Indigo Sig Vat

Waste not: Urine – Part 2: The Indigo Sig Vat

This post is part of a series exploring the historical and modern applications for human urine.  Part 1 is available here.

At the end of the previous post I left off with a short anecdote about how last year I set out to grow my own dye plants, and how after transplanting my japanese indigo (Persicaria tinctoria) too early I used urine as a fast-acting nitrogen fertilizer to encourage my plants to stop early-flowering and ‘force’ them back into a state of vigorous vegetative growth.  Vegetative growth is what we’re looking for here, as it’s the leaves of this frost-tender annual that contain the most of the indigo pigment precursor known as indican

Unique indican-bearing plants exist in many parts of the world.  Indigofera tinctoria is a legume native to India and Southeast Asia.  The similar Indigo suffruticosa is native to the subtropical Americas.  Woad (Isatis tinctoria), a brassica, is a native to the steppes of Caucasia that ultimately became the primary source of blue dye in medieval Europe.  Persicaria tinctoria is in the buckwheat family and is native to east Asia.  Before “true indigo” from India came to dominate the global trade of indigo pigment, each of these unique plants supported a dyer’s economy of their own in their respective native region as far back as 2000 BC.  This suggests that some form of indigo dyeing may have arisen independently among various far-flung cultures, but what’s perhaps most intriguing here is that the actual process of dyeing with indigo is not all that intuitive.  In fact, it’s quite likely the discovery of the process was accidental, and involved large amounts of – you guessed it – urine.

A small bed of Persicaria tinctoria in early summer

Indigo Chemistry

Indigo is unique among natural dyes.  Lightfast blue dyes are rare in nature, and indigo is one of the oldest dyes known to man.  It’s one of few substantive natural dyes; no mordant is required for a washfast dye that binds well to both animal fibers (wool, silk) and cellulose fibers (cotton, linen).  Indigo dye is extracted from indican-bearing plants and rendered useful by way of a series of chemical reactions that historically speaking, have only recently been fully understood.

On a molecular level, indican is a glucoside.  Think of a glucoside as a sort of two-part molecule with a loosely connected glucose and non-glucose component; indican is part glucose, part indoxyl.  When held under water for some time, enzymes cleave the molecule into its two components where then bacteria consume the glucose, and the indoxyl component is left in solution.  Under water, the soluble indoxyl is in itself colorless, but when exposed to oxygen it becomes the dark blue and insoluble pigment indigotin.  If allowed adequate time to settle, water can be decanted and the remaining indigotin can be dried and stored as indigo cakes or powder.

indican to indoxyl



Under the right conditions indigotin powder can be made soluble again in the concentrated amounts necessary for dyeing shades of deep blue.  This a two-stage process: Insoluble indigotin must first be chemically reduced before it may dissolve in alkaline solutions.

Indigo dyers meet these conditions by preparing a vat of alkaline liquid that includes some sort of reducing agent.  Indigo powder is added, and upon reduction the vat may turn a muddy yellow or green color.  Now ready, the undyed material  is lowered in the vat and soluble leucoindigo soaks in and mechanically adheres to the fibers, where then upon removal and exposure to air it reverts back to its insoluble form.  Deep shades of blue are possible through a process of repeated dips following aeration.  To watch this process is a one-of-a-kind, almost magical experience: immediately after removal from a well-reduced vat the fiber will be a grassy green hue that morphs into brilliant blue right before your eyes.

With the insight of modern chemistry, dyers can now choose between natural and synthetic indigo powders of varying purity, and among an array of alkaline powders and reducing agents from which to build their vats.  In ancient times, however this was not the case – conditions for a suitable vat were made possible by bacterial action in aged urine


An excerpt in a circa 300 A.D. collection of ancient craft and dye recipes known as the Papyrus Graecus Holmiensis confirms that by this time urine was commonly used in Europe and Northern Africa for processing indican-bearing woad:

“105. Dyeing in Dark Blue. Put about a talent of woad in a tube, which stands in the sun and contains not less than 15 metretes, and pack it in well. Then pour urine in until the liquid rises over the woad and let it be warmed by the sun, but on the following day get the woad ready in a way so that you (can) tread around in it in the sun until it becomes well moistened. One must do this, however for 3 days together.”

The ancient text of the Papyrus Graecus Holmiensis AKA Stockholm papyrus

In his book The Art and Craft of Natural Dyeing author J. N. Liles writes how some of the earliest indigo dyeing was done by using fresh plant material in containers of stale urine.  Soap was unknown to the ancients; available cleaning agents would have largely been limited to alkaline liquids like wood ash lye and ammonia in aged urine.   Niles writes that urine was:

“…collected and stored by literally all primitive cultures. If, by chance, some indican-bearing plant material found its way into a urine vat, the bacteria growing therein would render the vat in a reducing condition (use up the oxygen and release hydrogen) and the ammonia, being alkaline, would dissolve the resulting indigo white.  Now, if some fiber fell in the vessel, and if it were retrieved later, the yellowish green material would turn blue before the eyes of the retriever, and the material would be dyed a permanent very pale blue”

It takes a lot of plant material to make shades of deep blue.  A fresh leaf vat, certainly that of the relatively weak woad, would indeed yield a very light color.  The deeper shades we now associate with blue jeans would certainly require concentrated vats, made possible by using extracted indigo pigment.

Indigo Pigment: Water Extraction Method

Powdered indigo pigment can be extracted from indican-bearing plants by a fermentation process that typically takes 3 to 5 days.  Immediately upon harvest, leaves and stems should be rinsed and then placed in a suitable container and covered entirely with water.  Warm water speeds up the reaction.  It’s important to make sure leaves are clean and completely submerged; dirt and oxygen are not helpful here, their presence will decrease yields and contaminate the final product with the unwanted related compounds isatin and indirubin.  

Preparing Japanese Indigo for water extraction

Over the 2020 growing season I was able to harvest my 40ft² bed of japanese indigo a total of three times.  The fermentation step for each extraction took the expected 3 to 5 days.  It’s during this time that enzymes are working to cleave the aforementioned indican molecule into its constituent parts: glucose and indoxyl.  Here’s where things get interesting: Over the next few days glucose is consumed, indoxyl moves into solution, and the ferment takes on an antifreeze-like otherworldly neon blue/green color.  The smell here is very apparent too.  Odd, sweet and only slightly rank is what we’re working for.  Over-fermentation leads to dramatically lower pigment yields, and this disappointment will be matched by a shift to an intense, distinctly putrid smell.  I’ve read of one person who described the smell as ‘like a shrimp boat’.  For me, it has a definite low-tide smell, but with the faintly sweet smell of tempura.  When fermentation is complete, indoxyl is in solution and has not yet deteriorated.  Smell really is your best cue here, and better judgment is said to come with experience.

Otherworldly hues from fermenting Indigo leaves

When fermentation reaches that sweet spot, pour the water into another vessel while straining the plant material.  I go for as much liquid as I can and give the wet, slippery leaves a good squeeze before turning them under the compost pile.  Recall that when indoxyl is exposed to air it shifts to the dark, insoluble blue pigment Indigotin.  First, however, the solution should be brought up to a higher pH by addition of some alkalizing agent.  Though some have said to have success obtaining pigment without adjusting pH, the settling process absolutely takes much longer and with likely lower yields.  There are options here: wood-sourced potassium hydroxide/carbonate was almost certainly historically common, nowadays slaked lime (calcium hydroxide, sold in grocery stores as pickling lime) is a nice choice. Slaked lime doubles as a flocculant here, greatly speeding up precipitation, but also contributing to an impure product.  It’s best to use as little as necessary – start with as little as .5 grams per gallon of solution.  Aim for a pH  between 9 and 10.

The blue/green water is now ready for oxidation and dependent on scale, there are multiple ways to go about this. In the days of the indigo plantations around the world  it might be common for lower-caste workers, or even slaves, to literally stand in and kick air into alkaline pools of reduced indigo.  On a small enough scale one can repeatedly pour the solution back and forth between containers.  For my 10 gallon batches I use the same air pump and manifold I have for making aerated compost tea at home.  With the air pump I can sufficiently oxidise the solution in a matter of a few minutes.   Now, given enough time at rest, indigo pigment should settle down leaving behind a supernatant of clear, brown alkaline water.

Introducing oxygen via air pump manifold

Precipitated indigo powder

At my scale it’s easy to start a siphon to decant the water into five gallon buckets.  At a pH of 9, I’m not too concerned: this water goes over the compost pile.  Once the excess water is carefully removed, I’ll consolidate the remaining watery paste and pour over coffee filters.  Once water is fully drained out, Indigo pigment extraction is essentially done. The resulting paste can be stored in airtight containers in the refrigerator or dried completely and is indefinitely shelf stable.

Draining excess water from indigo paste

Dried indigo powder can be indefinitely stored in airtight containers

Much of the indigo pigment extraction process, with all its nuance, is detailed in this document from  A special thanks goes to the moderators and community at the Indigo pigment extraction methods facebook group – the kindhearted souls there bring hope for the future of social media.

Sig vat

The urine vat – referred to by practitioners as the Sig Vat (a name of obscure origin) – is certainly one of the oldest methods for dyeing with indigo.  If you read my prior post, you may recall that urine is typically about 95% water and somewhere around 2 to 3% urea.  As urine ages, the natural enzyme urease transforms urea into ammonium, hydroxide and carbonate ions which causes the pH to rise from it’s slightly acidic starting point to about 9.   Now slightly alkaline, the urine is largely considered safe from pathogens (e.coli, among others), but it is certainly not a sterile environment.  Bacteria are already at work here contributing to urea transformation, and all the while also consuming organic compounds and additional nutrients in the urine.  Bacterial action releases CO₂, therefore creating the alkaline and low oxygen environment necessary for reducing indigo pigment.  Compared to urine collected throughout the or from that of beer and coffee drinkers, the relatively higher urea concentration in morning urine contributes to a more potent vat.  Allegedly, the urine from diabetics is best – this makes sense – higher glucose levels would promote more robust bacterial-induced oxygen-reduction.

Compared to other indigo processes involving chemical reductants, my experience is that a sig vat is a comparatively weak, slow and fickle process.  Maintaining a functioning vat takes effort:  the vat must be kept warm, introduction of air should be kept minimal, and special care must be taken to keep out chemical contaminants lest they disturb the active biology.  Japanese researchers have worked to isolate the specific bacteria that are well-suited to this alkaline, oxygen-free environment.  In this research, they determined that acidic ‘micro-environments’ may form, that can be mitigated through daily stirring.  Additionally, Indigo powder must be ground very finely.  Some suggest introducing powder to the vat by means of a suspended filter – imagine an indigo tea bag – kneaded on occasion, where then only the fine indigo particles are able to pass through.

Preparing a slow-release indigo ‘tea-bag’

The inherent weakness of the vat does have its advantages.  There is the personal satisfaction of learning a process that is very old, that no doubt must have seemed quite magical  to the ancients.  Atavistic tendencies aside, the lack of harsh chemicals here does reduce the risk of damaging fabrics.  When building shade a weak reducing environment prevents re-reduction of pigment on the fiber during re-dips.  Some fabrics can be left in the vat for extended periods of time, ensuring very deep and permanent penetration of dye into the fiber matrix.   In fact, as J.N. Liles points out in another excerpt from The Art and Craft of Natural Dyeing:

“The alkali of the urine vat is the least damaging of all alkaline substances to wool, and for the reason buyers of indigo-dyed woolen yarns and woolen articles often would not purchase such items if they did not smell right”

Sig Vat attempt #1

My first attempt at a sig vat was in the early months of 2020 – long before I had any of my own homegrown pigment.  Instead, I was using a 45% purity indigofera tinctoria sourced pigment, found here for sale in small quantities.  I collected enough daytime urine to fill a 2-gallon wide-mouth jar within 2 inches of the top.  Then, I loosely covered the jar with an old t-shirt and moved it into a back corner of our biocharprocess-heated shipping container.  This is a multi-functional space that we had originally setup for rearing black-soldier larvae and at this time in late winter, temperatures for the most part were maintained around 70 degrees.  At this time of year it is not unusual for daytime temperatures here to climb up to 80 degrees.

Using the 1 tsp/liter ratio described in Kevin M. Dunn’s Caveman Chemistry, I measured out 2.5 tablespoons of pigment for my 2 gallon vat.  Using this blog post as my guide, I made a ‘sock’ from a scrap of old t-shirt and mason twine, weighted with a stainless steel nut.  As Dunn describes, using smell as my guide, the urine was already turning after only a few days at this temperature.  I dropped in the ‘sock’ and, while wearing gloves, gently ‘massaged’ it to slowly release indigo – the color change in the vat was nearly immediate.  A few more times throughout the next week I gently stirred and released more indigo into solution.   After a week or so, essentially guessing, I made a determination the vat was ready.

Adding indigo powder to my first sig vat.  Blurry photo taken ‘in the moment’

Dyeing with this first vat was quite successful, but still slow when compared to the more common hydrosulfite vat.  I started with a set of 6, 2 oz cotton napkins, and found I had room to dip 2 at a time, where I kept them submerged for 20 minutes.  I found I could dip and wring-out each pair only once before a noticeable color shift in the vat – the deep green, reduced vat would shift to blue after introducing too much oxygen.  At this point, I would need to wait at least another day for reduction to take place before my next dip.

Some of the cotton pieces were dipped up to 8 times, at which I was able to build some fairly dark shades.  Once I was satisfied, I poured the nearly exhausted vat over large wood chip piles and thoroughly rinsed the all 8 cotton cloth napkins in cold water until the rinse water ran completely clear.  The entire process took me about 3 weeks, although I suspect shorter reduction intervals would have been possible.  Lastly, I should mention the smell vanished after a single wash in a machine and after almost a year of occasional use these pieces have maintained nearly all of their original color.

Building shade in early winter at the biochar facility

Sig Vat attempt #2

By mid-summer of 2020 I was ready to try another sig vat with my homegrown indigo pigment. This was the pigment from my second extraction – and no doubt the indigotin concentration (purity) of each extraction increased with experience – the purity of this batch was indeed quite low.

Again, I collected two gallons of ‘normal’ daytime stored in the same glass jar.  Outdoor temperatures now modulated between an average nighttime 60 and 80.  I placed the glass jar inside a five gallon bucket with a lid and kept in a sunny location in the garden.   After a week I added ½ cup of refrigerated indigo-paste directly to the vat.  For me, the ½ cup was a bit of guess – Assuming at the time that I had both accounted for lower purity and additional moisture content, this concentration ultimately proved to be quite dilute.   Nonetheless, I was able to dye light shades on a pair of lightweight cotton batik dish towels.

A first attempt at a simple batik, sig vat dyed in the garden


Historical context and detailed ‘recipes’ all kinds for natural dyers, including in great detail the construction of indigo vats, preparing fibers and troubleshooting: J.N. Niles: The Art and Craft of Natural Dyeing: Traditional Recipes for Modern Use

An amusing and eccentric history of the chemical industry, with project-based lesson plans:   Kevin M Dunn: Caveman Chemistry

A very helpful and active community of natural Indigo processors

A detailed account of both composting and water-extraction methods for isolating indigo dye from plants: The Production of Indigo Dye from Plants 

Waste Not Urine

In his posthumously published 1911 work Farmers of Forty Centuries, USDA agronomist F. H. King documents his travels studying the intensive agriculture of China, Korea and Japan.  Multiple references are made to the efforts of farmers and city-dwellers alike to collect and distribute human waste to nearby farms as a valuable source of ongoing fertility:

“In such public places as railway stations provision is made for saving, not for wasting, and even along the country roads screens invite the traveler to stop, primarily for the profit of the owner, more than for personal convenience.”

Ancient Roman launderers known as fullones collected human urine from the public in small pots set alongside the street,  diluted it with water and used it to aid in removing dirt from clothes.

In a vain attempt at producing gold, 17th century alchemist Hennig Brand accidentally discovered elemental phosphorus while heating in a retort the residues of some 5,500 liters of boiled down urine.

In his book At Home: A Short History of Private Life, author Bill Bryson writes about how before “sanitation’s greatest champion” Joseph Bazalgette started work on the central sewers of London, he had built his reputation on a plan to construct public urinals throughout the city, where then the urine would be collected and sold to industrial processors of alum.

Historically speaking, it’s clear that the current ‘flush and forget’ system of human waste disposal is abnormal.

In Bazalgette’s time, London’s growing population was experiencing cholera outbreaks that were widely thought to be the result of breathing the foul smelling air around the open sewers that led to the Thames river.  It wasn’t yet widely understood that diseases were spread by fecal contamination in drinking water.  Bazalgette’s contribution was to enclose sewers and pump and dump the waste further downstream, offsetting the offensive smell, while also incidentally beating the cholera crisis by moving the human waste further away from the source of London’s drinking water.

Nowadays, wastewater treatment systems are very effective at keeping fecal-derived pathogens out of our drinking water, but it comes at a cost.  In a system where nutrient-rich liquid waste is diluted with flush water, mixed with fecal matter and whatever else people put down the drain, nutrient recovery at the sewage treatment plant becomes challenging and expensive.  The majority of modern sewage plants are designed to remove most of these nutrients before discharge, typically either through chemical flocculation, various means of microbial immobilization or some combination of both.  The resulting phosphorus and nitrogen-rich sludge may be anaerobically digested or further treated and applied as a (somewhat controversial) fertilizer, but more often than not (as is the case with my local wastewater plant) it is incinerated or landfilled.  Moreover, although the liquid effluent from sewage plants is largely free of harmful pathogens, some contamination still persists: pharmaceutical contaminants or hormones may still be present, along with remaining nitrogen and phosphorus, further contributing to nutrient pollution in our waterways.

In recent decades, researchers in Europe and stateside organizations like the Rich Earth Institute in Vermont are advocating for a new approach to managing human waste where nutrient reclamation and sustainability takes center stage.  Sometimes called Ecological Sanitation or ecosan, these are whole systems designs that attempt to ‘close the loop’ on human waste and agriculture.  Common among these designs are urine diverting dry toilets (UDDT) where urine is kept separate from feces and flush water and stored in holding tanks to be applied directly as a fertilizer at nearby farms.

Urine diversion represents a sort of ‘low-hanging fruit’ in ecosan system designs. Compared to feces and kitchen waste water, urine is very easy to manage for pathogen reduction.  By volume, urine accounts for only 1% of domestic wastewater while comprising up to 80% of the nitrogen, 55% of phosphorus and 60% of potassium.  Urine is a potent fertilizer that is well balanced for grain production:  an often cited Swedish publication from 2004 states that over the course of one year the average person produces enough urine to fertilize a 250kg crop of maize.

Urine accounts for most of the possible major plant nutrients that are flushed away in domestic wastewater.Source

Seeking a deeper understanding of the science of nutrient cycling, in early 2020 I set out to explore firsthand the historical and relevant modern uses for human urine.   In a way it was good timing – the isolation brought on by the Covid-19 pandemic enabled me to invest more time in these admittedly anti-social projects.  Ultimately, there’s too much to cover in one post.  Here I’ll cover in detail the issues with urine collection and agricultural applications.

In later posts I’ll share my efforts with a historical method of using urine for processing indigo dyes and saltpeter production, experiments with the use of urine in recirculating hydroponic systems (known as anthroponics, or pee-ponics), and lastly I’ll share my trials with a low-tech process of struvite precipitation, yielding a potentially valuable, easily transported and stored urine-derived mineral fertilizer.  But first, in order to discuss urine applications in any detail, we need to know more about what’s in it.


Healthy human urine is between 91% and 96% water.  Over half of the non-water fraction is the nitrogen-containing compound urea.  Nearly all of the Nitrogen in fresh urine is the form of urea.  The remaining portion is a panoply of mostly innocuous organic compounds and inorganic salts.

These figures for average nutrient concentration in human urine were published in the 2011 report: Technology Review for Urine Diversion Components

The elemental composition of urine changes with diet.  Urea is a product of the metabolism of protein.  Meat-eaters should expect their urine to have higher nitrogen levels, as well as higher levels of phosphorus and calcium.  Conversely, those with a largely vegetarian or protein-limited diet should expect a higher pH urine with a higher ratio of potassium.  Additionally, urine collected in the morning – the first after waking up – has been shown to have comparably higher levels of urea, calcium and phosphorus.

It has been said that adults are essentially at a ‘steady-state’; major plant nutrients nitrogen and phosphorus are no longer needed to grow, and thus not retained in the body.  A diet rich in minerals will produce mineral-rich urine.  On the flipside, diets high in common salt are going to reflect high sodium and chloride levels in urine.  Pharmaceuticals can be persistent too, leading to valid concerns over the use of urine as a fertilizer and subsequent accumulation in agricultural soils; this has been the focus of much ongoing research, where a symbiotic application of biochar may be a solution.  Urine is the product of filtering blood through the kidneys and contains only substances that have been metabolised. Heavy metals are largely a non-issue; metals are removed from the body as feces – a combination of both metablised and non-metabolised material.  Interestingly it has been shown that when compared to expulsion via urine, sweating from the result of vigorous exercise is a much more effective means of removing metals from the body.

Is it Sterile?

Technically, no. Contrary to popular belief, human urine as it exits the body is not absolutely sterile.  However, it should be noted very few diseases are transmitted via pathogens in healthy urine.  In Carol Steinfeld’s book Liquid Gold: the Lore of and Logic of Using Urine to Grow Plants we are told on the authority the Swedish Institute of Infectious Disease Control that significant urine-transmitted diseases Leptospirosis and schistosomiasis are only of particular concern in humid, tropical environments.  Salmonella is potentially transmittable through urine but is inactivated quickly after excretion.

There seems to be a general consensus among urine-reuse advocates that the risks of infection are nil if the urine is collected only from healthy members of your own household and destined for application on crops consumed only by the household.  The conventional wisdom here is that you cannot get a disease from your own urine that you don’t already have.   However, problems arise with fecal cross-contamination, and I suspect this is more often the case than I expect most people would like to know.  In her presentation for the 2020 Rich Earth Summit, ASU researcher Daniella Saetta and team shared their work in identifying microbial communities in urine collected in waterless urinals – of all the samples, none were without contamination.  For all practical purposes we should assume urine may harbor pathogenic bacteria and that come harvest time you may decide to share the produce with friends outside of the household.  This is not to say we should be scared, but rather cautious.  The risks can be easily mitigated through a regime of pre-treatment and best practices upon application in the garden.

Pre-Treatment for Safer Agricultural Use

Recall that fresh urine is slightly acidic. It’s mostly water, while the remaining portion is mostly urea, along with some inorganic salts and various organic compounds.   Among these organic compounds is the enzyme urease.  Urease is naturally found in both urine and soils, and is ubiquitous among other many species of plants, fungi and bacteria.  Urease is the catalyst by which through hydrolysis urea is ultimately converted to ammonium and hydroxide and carbonate ions.

Hydrolysis of Urine: By far, the simplest method for pre-treatment

Hydrolysis of urea and the resulting conversion will raise the pH from its starting point to at least 9.  Pathogens are deactivated after a length of exposure in this high pH environment.  This is an easy strategy for pre-treating urine prior to agricultural application – it’s largely a spontaneous process, all that is required is proper storage.   Odorless ammonium easily shifts to gaseous ammonia, complete with it’s potent, distinctly pungent odor.  Storage containers should remain closed but not necessarily gas-tight.  The goal is to keep this volatile nitrogen dissolved in water, rather than lost to the air.

Under normal circumstances, hydrolysis may take anywhere from a few days to weeks.  The speed of the reaction is largely temperature dependent – higher temperatures will speed up the reaction while very cold temperatures will nearly stop it.  The rate of the reaction is also dependent on the amount of urease in the urine.  Scientists have shown this through supplementation with urease found naturally concentrated in the jack bean.   Researcher Henrique Sanchez has shown that by adding 1 gram of dehulled, crushed watermelon seeds to 100 mL fresh urine he was able to facilitate hydrolysis within 20 minutes.

Addition of watermelon seeds can speed up the hydrolysis reaction.  In my trials I determined seeds should be crushed with a mortar and pestle, but dehulling was tedious and unnecessary.   24 seeds (.54g when dehulled) helped bring 600mL of 6.8pH urine up to 9 in less than 20 hours.

Hydrolysis of urine is an easy way to safeguard urine from pathogenic bacteria but it is not without its downsides.  Containers must be kept at a moderate temperature for at least a month or more.  The WHO recommends retention times above 8.8pH for 1 month when applied to fodder crops or those that will be later processed, and 6 months when applied on crops to be eaten raw.

The conversion of urea to volatile ammonia all but sure ensures that some nitrogen will be lost to the atmosphere.  The smell is potent, and even though it has been said to dissipate quickly, make no mistake: doing anything with aged urine is likely going to be a lonely experience.

Another complication associated with hydrolyzed urine is the formation of struvite.  Struvite is a mineral form of magnesium, ammonium and phosphate that precipitates out of stored urine as the pH rises.  The formation of struvite leads to scaling of fixtures and clogging of pipes in urine diversion systems.  The sediment builds up on the bottom of collection tanks and can clog fertigation equipment.  It also changes the nutrient profile of the urine – all of the magnesium and most of the phosphorus will precipitate.  Calcium too, will precipitate under high pH conditions.  This is not to say these minerals are unavailable as plant nutrients – quite the contrary – struvite formation has been seen by some creative engineers not as a problem, but as a low-tech and accessible way to reclaim nutrients from urine in a solid form.  Gardeners can be sure the mineral component of urine is delivered to soil through dilution and stirring before application.

Nutrient Analysis of Human Urine Before and after Hydrolysis.  Source

Problems associated with struvite and ammonia losses from hydrolyzed urine are one of the reasons researchers are looking for alternative ways to sanitize urine.  Some have suggested treatment with citric acid to deactivate pathogens by adjusting pH down while also preventing struvite formation.  The Rich Earth Institute employs a pasteurizing system.   Others in the permaculture community have experimented with fermentation of urine along with wood ash and dynamic accumulators such as comfrey.  Lacto-fermentation of the comparably phosphorus and calcium-rich morning urine is the method I’ve chosen for use in my recirculating hydroponic system (more on this in a future post).

Urine as a Fertilizer

Urine is a free and natural source of fast-acting, soluble nitrogen that compares well to widely-used industrially-produced urea and ammonium fertilizers.  Recall that nearly all of the nitrogen in fresh urine is in the form of urea.  Upon application in the soil, as in urine hydrolysis, soil-borne urease works quickly to convert urea nitrogen to ammonium nitrogen.  Ammonium is in itself a plant-available source of nitrogen; ammonium may also be converted in the soil to plant-available nitrates by way of nitrifying bacteria.  Nitrate conversion typically occurs in a few days.  Biologically active soils will see faster conversion.

Nitrification: Conversion of Ammonium to Plant-Available Nitrates

Other major plant nutrients – phosphorus, potassium and sulphur are found in urine in their readily available ionic form.  Researchers in Sweden determined that locally-sourced urine had an NPK ratio of roughly 12:1:3 and was well-proportioned as a fertilizer for cereal production.  Still, nitrogen is the primary nutrient here – urine alone is suited for nitrogen hungry leafy vegetables; supplemental potassium will be required to balance urine as an appropriate fertilizer for fruiting vegetable crops.  Joe Hollis from Mountain Gardens mixes urine directly in wood ash – a potent source of potassium, calcium and micronutrients.  Alkaline potassium and calcium will quickly raise the pH and deactivate potential pathogens, but will also encourage loss of nitrogen through ammonia gas formation.  Mixing urine and ash can be a suitable way to create a balanced fertilizer that will be best stored in closed, corrosion resistant containers.

Depending on diet, urine is likely to have a concerning amount of sodium.  Few common vegetable plants actually need any sodium at all, and therefore sodium accumulation in soils can reach harmful levels if left unchecked. In our humid climate in the Eastern United States rainfall will usually be enough to leach unwanted salts in outdoor gardens.  However, gardeners must take special care not to allow excessive salt buildup anytime when growing under cover, or during periods of drought. This is especially the case with any indoor growing  – potted plants, greenhouses for example.   This is one reason why occasional deep irrigation is often recommended.

Application Methods and Rates

As a directly applied fertilizer, urine should be applied in methods that minimize ammonia volatilization,  both for fertilizing efficiency and curbing offensive smells.  Band application, low to the ground, is most appropriate for larger scale projects.  In the garden, ammonia losses can be mitigated by applying in small holes or furrows alongside  crops and immediately covered after application.  The same technique can be applied with mulches when pulled aside and covered again after application. As a rule-of-thumb, keep urine 4” away from the base of the plant.  Trees can be fertilized to the dripline.  Nitrogen efficiency will be greatest in soils that are rich in organic matter, where urine is readily absorbed and won’t leach through or evaporate quickly – reducing losses from both above below.

Urine is easily measured, diluted and applied with a watering can when stored in small containers.

Avoid spraying altogether – foliar application will damage leaves as water evaporates and concentrates salts.  Application of through drip irrigation is likely to cause problems due to precipitation, but may be an appropriate method for the remaining phosphorus-free, yet still nitrogen-rich liquid that remains after struvite precipitation.

Dilution of urine with water prior to application is a common practice that isn’t entirely necessary.  The Rich Earth Institute determined that there were no adverse effects of applying undiluted to hay.  However, in the garden more precise application is possible when urine is diluted, and dilution helps prevent over-application and alleviates the risk of damaging roots.  Garden vegetables are likely less tolerant of the high sodium content in urine; excess water in diluted urine will help evenly distribute all minerals, lessening the impact of concentrated salts.  On a large scale dilution is not always practical, increasing labor and contributing to soil compaction issues, where larger tanks are required to carry additional water.  A better strategy may be to apply urine at full-strength followed by light irrigation.  In either case, urine is best not applied to dry soils.

Application rates are dependent on nitrogen needs of the crop at the time of application.  Precise rates are all but impossible to determine without a urine nutrient analysis, however, we can make some assumptions based on published data. The Rich Earth Institute estimates there are .05 lbs of nitrogen (N) per gallon of urine.  Much of the Swedish literature assumes 7 g N per liter – the equivalent of .063 lbs per gallon.  Assuming .05 lb N/gal, then 20 gallons will provide 1 lb N over 1000ft² – for reference, this is the amount of nitrogen a typical suburban homeowner would apply two or three times a year to their front lawn. A typical corn N recommended application rate may be 240 lbs/acre, or 4800 gallons urine.  Swedish trials found significant improvement in yield of winter wheat, assuming 7 g N/l, with an application rate of 120 Kg N/ha – the equivalent roughly 1,800 gallons urine.  According to Swedish estimates the average person produces between about 1.5 and 2.5 liters urine a day – the equivalent of 145 to 241 gallons/year.  Farm-scale urine fertilization clearly takes a community-scale collection effort.  Such a project requires committed participation from a range of individuals – daunting, yes, but not impossible.  Larger scale projects in Sweden have been implemented with installed urine diversion toilets and collection tanks and for their large-scale trials and the Rich Earth Institute has a program for accepting donations of urine from members of the local community.

Practical Advice

At a smaller scale the urine collected from even a single person can make an appreciable impact in the garden.  Collecting a little over a quart a day, a single person can supply a ½ lb N every month for a 1000ft² garden.  Vegetable crops are only fertilized during a portion of the growing season, so if urine is collected and stored throughout the year, one could reasonably fertilize a garden 3 or 4 times that size.  Alternatively, urine can be used in ways that support fertility without direct application to the soil.

At home I keep a smaller dedicated vegetable garden space, a small orchard of 10 fruit trees and grapes, along with a patchwork of ramial chip mulched beds.  I collect urine in a simple five gallon bucket in a private location outside on my property.  Only 3 or so partially filled buckets will be stored and treated through hydrolysis for direct application on garden vegetables.

Lately I’ve been collecting morning urine separately in quart or gallon size plastic jugs and fermenting it and storing for a month before use as the primary nutrient for my recirculating hydroponic system – a little goes a long way here.  Smaller storage jugs are easier to measure, dilute and pour into handheld watering cans for targeted application.  As a male, it’s easy to use these, and for now, I prefer to keep it simple as I don’t expect anyone else in my family will be excited about contributing their own for a long time. 

Outside of the garden, urine is applied in the orchard and occasionally on the compost pile. Diluted urine is applied once a year in the early spring on select trees in the orchard.  Often I’ll take a half-full 5-gallon bucket and top it off with water before pouring over a thick layer of ramial wood chip mulch under the drip line of individual trees.  Nearly all of my fresh food waste goes to the worm bins – urine is not welcome here. However, in the fall I’ll start a passively aerated compost pile for carbon-rich yard and garden cleanup, and here, urine is absolutely a helpful way to apply nitrogen that facilitates decomposition of woody material.

Passively aerated carbon rich compost, including biochar and urine

It seems in nearly all of our biochar presentations, someone in the crowd inevitably mentions charging biochar with urine.  There is wisdom here.  High temperature biochars especially have been shown to retain nitrogen and phosphorus anions.  A common strategy here is to pre-treat, or ‘charge’ the biochar with urine before mixing as an ingredient in the compost.   I use this method as means of including both nitrogen and biochar in my carbon-rich static, passively aerated piles.  In conventional 30:1 C:N thermophilic compost,, it stands to reason that biochar may be more effective at absorbing ammonia gases when applied without a urine pre-treatment.


It was about this time last year I set out to begin establishing a dye garden.  Dyeing with indigo pigment is a fascinating process involving reduction in an alkaline vat – a condition that historically was met by using aged urine.  Out of some morbid curiosity of all things tedious, groomed through last year’s work with wood ashes, I set out to attempt the process on my own. Again, I’ll speak more about this in a follow-up post.

Germination of my Japanese Indigo (Persicaria tinctoria) was very successful – 90 frost-tender plants were ready for transplant in the greenhouses by mid-march.  Started early enough and managed carefully, some growers can expect 3, sometimes 4 harvests throughout the growing season.  However, it was about this time the Covid-19 pandemic became more severe and indigo plants were no longer a priority – space in the greenhouse was to be reserved for food and medicine.

Mid-April is our average last frost.  In prior years our final spring frost had come very early and I retained some hope I could transplant by the first of April in my own garden.  Around 60 plants were well established after a month in a 40 ft² before a late April cold snap arrived.  A low tunnel kept enough heat in to prevent frost damage, but the cold was enough to signal early flowering.

Early spring flowering

Nitrogen is known to encourage vegetative growth; urine is a well matched fertilizer for leafy greens.  Following this logic, I pinched off early flowers and applied a heavy dose of 1 gallon urine, diluted with 3 gallons of water, over the 40 ft² bed.  In two-week intervals I repeated this process 3 more times so that an estimated .2lbs of N was applied in an 8-week period.  By late spring flowering had largely stopped, and despite the early season setback, I was still able to harvest completely 3 times throughout the growing season.  Urine would prove to be well-suited for both growing and processing my indigo crop.

Did applying a heavy application of urine fertilizer force my early-flowering Japanese Indigo plants back into vegetative state?

Helpful References

The Rich Earth Institute is researching and advocating for urine use in agriculture in the United States.  Their Home Use Guide is a helpful summary of best practices in the garden.

Guidelines on the Use of Urine and Feces in Crop Production

A Technology Review of Urine Diversion Components

A report on urine diversion with concrete examples of use in agriculture: Urine Separation – Closing the Nutrient Cycle

WHO Report: Urine Diversion – Hygienic Risks and Microbial Guidelines for Reuse

How I Caught the Steer

Our blog for December is a true story from Living Web Farms’ livestock manager, Rocco Sinicrope.

Let me tell you about the time I caught the steer.

When we were first starting in the cattle business I figured we were a little too small for a cow calf operation.  We were, after all just beginning and I had next to no experience.  That, topped with the fact that we only had 20 or so acres of grass which is comparatively small and the responsibility of a breeding program was enough to convince me to start off with an all in all out.  Granted that jumping in head first does have its advantages when it comes to hands-on learning, but, in this case familiarization of alternative grazing systems was the priority.

 All in all out basically means you buy steers and grow them to market weight, then sell the beef.  A stocker program like this typically produces beef faster than a breeding system, but you are subject to whatever animals you can find.  I was a student of what I’ll call alternative grazing techniques as opposed to the traditional, and I was dying to implement mob grazing, high density grazing, multi species animal impact, and stockpiling grasses for winter.  That’s plenty to chew on and get under your belt without having to figure breeding as well.  Well, one thing at a time.

So where do we start?

Baby Big White

The livestock auction, or sale barn as it’s commonly known, is a fine time. In addition to a place to buy and sell cattle, It often acts as a community hub; lots of information gets passed along there both formally and via casual conversation.  I have experienced a strong sense of camaraderie at farmers markets both with other farmers and customers, and the sale barn has the same quality, I think primarily because raising livestock is next-level stuff.  I love vegetables and have been raising them for over 15 years, but in my opinion, livestock is more visceral. The energy exchange is more in your face.

For myself at that time however, the mysterious nature was enough to make me look elsewhere.  I’m glad I went, and I still go from time to time just to keep myself honest, but I learned that some folks take their best stock there, and some take their worst. The problem for me at the time was my inability to really tell the difference. I kind of figured why not go to the source?  Besides, who the hell can understand that auctioneer.

Knowing a little historical background on the animals you are buying and bringing to your farm is useful because it gives you more of an idea of how these animals were raised and the lives they have led.  The less they have to adapt to dramatic changes between where they are coming from in correlation to where they are going, the better off they’ll be.  This is how I came to meet Tommy Heffner.

I forget if it was Craigslist or the Iwanna (a local bulletin for this kind of trading) but one spring day I found myself headed to upstate South Carolina to meet Tommy who had come highly recommended by some good ol’ Mills River folks.  Tommy was a local Henderson County man himself who had moved down off the mountain a few years prior.  Presumably to have a little more room to roam and to find some land that was more affordable. I eventually arrive at Tommy’s farm and while driving in I recall being in deep thought, wondering if the rain I was driving through was the hardest I’ve ever seen.  I mean to tell you, it was pouring…hard.  So after seeing me pull up, he waved me into his shop, we introduced ourselves face-to-face, and from there it was obvious that we didn’t have much else to do but sit down and get to know each other.  I also had the chance to meet his wife, Francis and being stuck in their company was such a pleasure.  We talked and swapped stories for a couple hours until the downpour subsided and we were able to go look at his yearlings.

Geese are helpful defense against birds of prey for a chicken flock.

Tommy had all the hands-on farm experience that I lacked at the time, and I just sat there like a kid at his feet doing my best to soak in and glean all that I could.  I had all these ideas and concepts and theories but finally here was a real opportunity to bounce them off someone with tons of familiarity.  I don’t believe any of these ideas were new to him, but it’s fair to say he was more of a conventional practitioner, and if he ever thought my ideas or plans were off the wall crazy, he sure hid it well! It was like free consultation.  All-in-all, Tommy turned out to be a great resource for me, especially when I was just getting my feet wet.  He was encouraging and supportive, from time to time I’d call on him with a quick question or two or just to say hi, and from time to time he’d do the same.

Tommy has passed on now but as it turned out he was a big fan of frequenting the sale barn.  I’m not sure that he did a whole lot of buying and selling although I know he did some, but more to keep up on prices and spend a little time with buddies.  I wouldn’t necessarily call this a regret, but as I sit here and reflect on these memories, I sure wish I’d gone to an auction or two with him.

We ended up getting five steers from Tommy and he brought them to us a week or two later.  One thing my years of diverse vegetable production has taught me is the concept of staggered harvest via successive planting.  It’s nice to have a steady supply of produce coming in over the span of weeks or months as opposed to a one shot deal.  For example, the last frost date may be May 15th, but we typically plant tomatoes the entire month, and even into June to stagger the harvest down the line.  It also reduces risk because it provides a scenario where plants are coming into and going out of their peak production all at the same time.  Why not apply the same philosophy to the steers?

So when Tommy brought us his yearlings I thought I’d bounce an idea off him – would you bring me some older steers Tommy?  It made sense to him and at this point he had a pretty good idea of what I was looking for, although he didn’t have any steers that were in the age range I wanted, he said he’d be sure to keep an eye out at the sale barn for me.  A few weeks went by, the new steers had gotten accustomed to the frequent paddock moves that make up mob-grazing, and sure enough one day my phone rings and Tommy informs me that he just picked up three big steers for me and he’d see me tomorrow.  Great!  He shows up the next day, backs into the barnyard and we unload three of the prettiest Charolais crosses I’ve ever seen.

One red, one blonde, one white.

The steers as they arrive

Charolais are a French beef breed. Most American cattle (at least in this area) are some cross of European beef breeds; Angus, Hereford, and Charolais are among the most popular.  They unloaded fine and for the most part fell in line with my management system – which includes being moved into relatively small paddocks every 12-24 hours in an effort to maximize efficient use of grass, heavily impact weed pressure, boost fertility, and conserve stockpile grasses for the dormant season.  The cattle herd was running with a flock of hair sheep and two donkeys, giving us a flerd.  Moving all these animals at least once a day gives you a good rapport with them.  Among other things, one advantage in seeing them up close everyday is easy regulation of their body condition.  Point is, all these animals were moving along and getting along just fine.

However, there was something that I always noticed.  When I would walk out to them for a move, the big white steer would always be the first one to look up and keep his eye on me. Not the five smaller steers from Tommy, not the big blonde or red one, but always that big white.  He was always the last to go back to grazing after being moved into a fresh paddock.  He would see you from across the farm and never really settle until you were really far away.  For the most part, my little flerd was just chugging along that summer.  The big white steer never really got too excited about anything, he was just always the first one to stop what he was doing and check you out but he complied and followed all his companions into the next paddock so I never really paid it much attention.  Things continued that way for quite a while until it was time to load them for the processor.

Moving livestock somewhere they want to go – like a field full of fresh, lush grass is one thing – moving them somewhere they’re not too sure of is another.  A livestock trailer is a prime example.  The best way I have found to get cattle loaded is to simply take your time and get them accustomed to it.  If you have a handling facility with a loading chute it’s pretty easy to get them loaded, but if like me you don’t, you have to do the best with what you’ve got.  Expecting cattle to walk right onto a dark, confined space that they are unfamiliar with can be a tall order, here is my recommendation.

Cattle that don’t fear you are much easier to work with.

Park your trailer in a location that isn’t out of the ordinary.  Secure the wheels and jack so it has no chance of rolling away or shifting when a couple thousand-pound animals walk in it.  Prop open the back door in a way that is secure,  but allow yourself the ability to shut it quickly and quietly should the opportunity present itself.  Put the water trough all the way in the back.  Put it in a spot where the livestock have to walk the entirety of the trailer floor to get a drink.  Then simply walk away and give yourself a few days for the animals to learn that nothing bad happens to them on the trailer.  If you have a date for the processor, or some other reason to move them, just work backwards and set yourself up three or four days in advance to relieve any stress by building familiarity.  When the time comes to load them, now they are accustomed with where you want them to go and it’s so much easier than having to force them.

Another little trick that can come in handy is using sweet feed as a little treat for the livestock.  Sweet feed is a highly palatable treat for cattle that seems to have the same effect on them as ice cream does for children.  Not only can it help to lure cattle, it also trains them that when they get  on the trailer a nice surprise awaits them, thereby associating the trailer with good thoughts – a mobile sweet morsel facility, as opposed to a big scary metal trailer.  Just feed them a little bit during the time they are getting accustomed to the trailer, and when the time comes to get them loaded, you throw a little in the bin and the cattle come running and you simply shut the door behind them.  Done – stress free.  It’s just a helpful trick to know and to have in your toolbelt.  A couple handfuls in their last days as a treat and to get them where they need to be with no hassle is worth it in my book.  To make my point even further I once saw an old-timer load a dozen hogs on a trailer simply by walking on it and they all followed him, then a buddy shut the door, he strolled to the back and his friend let him off.  All the pigs ready to go, the whole process probably took 20 seconds. Talk about making something look easy.   Amazed, I asked how he did that, it was like magic!  He walked over to me, looked me right in the eye and said “son, you gotta be smarter than they are.” He then reached in his pocket and pulled out a crushed up hand full of vanilla wafers.

Learning to work with livestock and how to move them is like learning another language. The more you do it, the more it becomes second nature to anticipate their next move.  Always keep in mind that we are not raising predators but prey. Now when you are standing next to an animal that is ten times you size, it’s easy to feel intimidated and for good reason, they can injure people and you should always be careful  If bulls and full grown boar pigs were all the size of cat and dogs I think the world would have a lot less farm accidents and there would be far fewer handling and loading issues.  My point is that the size of livestock can lead to people being intimidated by the animals they are trying to manage.  In and of itself it is a stressful situation that has the potential to get dangerous.  Observation leads to understanding, understanding leads to knowledge which in turn enables you to provide the most efficient and stress-free situations for you, the people around you, and the livestock. So to the best of our ability, let’s avoid the scene of scared people handling scared animals.

Livestock and handler engage in a dance to the tune of the animals’ comfort level.  You can stand 100 yards from a steer, and while it will notice you are there, more than likely it won’t react because you are too far away to cause immediate threat.  Now, standing 12 inches from a steer, you are now close enough to achieve physical contact, and it simply turns into a “too close for comfort” situation and simply goes into a get-out-of-there, flee-as-fast-as-possible state.  There is a beautiful and precise point.  This one little spot where the animals aren’t stressed, but they don’t want you to come any closer, when one step forward adds pressure and one step back relieves it.  That’s where the magic happens, where the dance begins, where you lead and they follow.  That precious place fluctuates between species and within species individual animals, but working that edge in a calm manner is the key to handling livestock.

The flock

So, back to the due date.  The three big steers had been gaining nicely all summer and it was time for them to meet their maker.  I had an appointment at the processor and it was time to get them ready for the one-hour ride to Forest City.  I put them in the barnyard and set up the trailer.  This was the first time I had them in a somewhat confined area – the barnyard is about an eighth of an acre with access to the barn for staples and cover.  Anytime I had previously looked or gone in there with them they didn’t get stressed or seem to really pay me any attention, but on loading day, something really spooked big white.  I’ve never been able to pinpoint what elevated his stress level so much. The other two were just fine but when I went to load them he ran back and forth the perimeter of the yard, trying to get as far from me as possible while me and the other two steers watched in surprise.  I decided to load big red and blonde by getting behind them and doing the dance with their comfort level. A step to the left to make them go right, a step to the right to make them go left, and a couple steps forward and they eased onto the trailer with no significant hesitation.  I pushed them all the way forward and closed the middle gate and turned my attention to big white.  As soon as I stepped off the trailer, he took one look at me, got a big run and sprinted toward the corner of the barnyard and leaped right out of it, back into the main pasture!  I had never seen anything like that before or since.  He had been on and off the trailer many times in the previous days but on that day he very clearly wanted nothing to do with it.

I stood there dumbstruck, scratching my head.  Well what now?  After a few failed attempts to get him back in the barnyard it was clear that he had no intention of cooperating, no intention in fact of letting me even get to a place where I could try and get him to cooperate.  It takes a while for animals to calm down after they have experienced high levels of stress, and after an hour or so of running around and trying my damndest to get him back in the barnyard, it was painfully clear that I had lost this battle.

I was a little embarrassed the next morning when I showed up to the slaughter house with two steers instead of three, but they were encouraging and seemed to understand.  Apparently I was not the first farmer who couldn’t get an animal loaded, so I made another appointment a few months out and figured I’d try again.  The other two big steers had been processed, but Big White wound up back in the rotation with the sheep and things returned to business as usual.  Round two approaches.

Fast forward a few months and it would be like rereading the previous couple paragraphs.  Now he knew the barnyard wouldn’t hold him and as soon as I even thought about trying to load him, he simply hopped the fence again.  It’s not that I couldn’t get him on the trailer;  I couldn’t even get him to a place where I could get him loaded.  Possibly the most frustrating part was that at this point I’d spent nearly a year with him, providing fresh pasture with daily moves, and he was still untrusting.  So I called the abbatoir and had to tell them I would miss yet another appointment, which was embarrassing at this point because it’s basically calling a business you had a deal with and telling them they won’t be making money today because I couldn’t keep up my end of the bargain.  Again, they were understanding but I made it a point to say I’ll call you when I’m ready and have him caught as opposed to making another date.  They happily accepted.

I’ve had a lot of teachers over the years and they have all helped and contributed in so many ways.  It still never ceases to amaze me how people can have two fully functioning regenerative farms, totally successful and have different management tactics.  This isn’t a one size fits all sort of thing and there are truly as many farms as there are farmers.  One of my teachers is Jim Elizondo.  I won’t try to describe Jim’s level of knowledge when it comes to cattle, genetics, and grazing, mainly because I wouldn’t come close to doing him justice, I mean he is really brilliant.

Living Web Farms is an educational farm and we do classes on various subjects for the public and sure enough Jim was coming here from out-of-state to teach a segment on stockpiling winter forage, complete with a little farm tour where we kept the flerd.  The morning of the class was cold and rainy and I was full of excitement.  While doing chores I had the bright idea to put big white back in the barnyard and add my unsuccessful attempts to catch him as part of a transparent class.  Plus, maybe Jim had some bright ideas on how to load him.   I hadn’t planned on doing this but convinced myself that it was a good idea although it put me in a bit of a rush.  So I hopped in my truck and set up the trailer in its spot, step one.  I opened all the gates and doors and made sure they were secure and easily accessible if a lucky opportunity should arise, step two.  I ran out to the feed store and picked up a bag of sweet feed.  A 50 pound bag is inexpensive and I use it so rarely and infrequently I thought I’d get a fresh one.

With the trailer set up and the lure in place all I had to do was cut out big white from the sheep flock and stick him in the yard. Up to this point, getting him from the barnyard onto the trailer was the problem, not from the pasture to the barnyard, so this shouldn’t be a big deal.  Maybe Jim had some secret way to load him and the participants of today’s class can glean some wisdom on animal handling, and I can get this animal on the trailer? A win-win for all people involved right?

Time was against me at this point.  It doesn’t take too long to set all that stuff up, but it’s the running around that will eat up your day.  I still had to go home, shower, put on some clean warm clothes and be the first one there to greet Jim with open arms and enthusiasm, all while putting on my hospitality hat for our guests while we all learn.

We use electrified mobile fencing or netting for the sheep. They respect it more than the single strand polybraid which a lot of operations use for cattle.  I also believe the netting creates more of a mental barrier for the sheep as opposed to just one lonely strand. It is formidable and encourages sheep to stay put.  As a quick side-note: sheep can be tough to keep in electric fencing.  They are light and agile so they aren’t particularly well grounded (not like hogs or cattle anyway) and they have a heavy wool layer that keeps their skin well insulated from the elements and electricity too.  Make sure your fence is real hot when you’re training sheep to respect electric netting.

It can be tricky cutting out different species from one big group.  While daily moves are routine at this point and everyone is well accustomed to them, it can still be challenging when you are moving three different species.  When the paddock where you want them is right next to the paddock where they are going it’s pretty easy, but there are those times when you have to move them across the whole farm.  Our routine at that point was mainly staying ahead of the donkeys because they had the highest level of confidence, not pressing the steer too hard because he is easily frightened, and giving the sheep plenty of space.  Moving sheep is interesting, they have the highest flock mentality so when you move them they really unify and act as one being as opposed to a bunch of different personalities.

On this day, the steer was feeling satisfied, and decided he couldn’t be bothered to move anywhere, while the sheep on the other hand were ready to high-tail it across the farm.  Why they decided to have such different reactions on what was otherwise a totally normal situation I don’t know, but I have since convinced myself that they had a meeting before I got there and decided to do their best to humiliate me.

Well, they did.  At this point I’m rushing.  Jim’s class has already started and I’ve been frantically going back and forth around the perimeter of the paddock trying to get the steer out and keep the sheep in.  The dance I described earlier is a good analogy, but some days are better than others and I was out there with two left feet.  The sheep would get out and the steer would stay, I couldn’t turn my attention to the steer cause the sheep would run off and then I’d have to go get them.  Soon as the flock went back in the paddock, the steer wouldn’t go anywhere and if I applied too much activity or pressure, he’d just jump over the netting.  It was mildly chaotic and that’s a bad state to be in when you’re working animals.

Again, this is something I do every day with no stress or struggles at all!  Why did it have to be today? I was due some humility because right when I was having all those thoughts, at the peak of my frustration of running back and forth around the electric netting, I ran up to it to keep the sheep inside, slipped in the mud right in front of netting, snagged the bottom of the netting with my boot as my feet lifted into the air and over my head, and then came crashing down with a thud, square on my back only to have the netting land right on top of me and give me a couple good jolts until I could crawl out from underneath.  I got up and put the fence back together, knowing that I had clearly lost this day.  Cold and wet, muddy and tardy, I showed up to my instructor’s class thirty minutes late, a beaten man.  Humility served.  I spent the class huddled in the back corner kinda hoping no one would notice me.  Suffice to say, when it was time for the farm tour I stuck to the subject matter at hand – grazing, not herdsmanship.

There were a couple more unsuccessful attempts that winter and spring which granted the same results, the steer was still around and any new plan of mine to load him proved unsuccessful.  It got to the point where I simply didn’t know what to do.  I couldn’t get him loaded. In fact, the worst was I couldn’t even get him to a place where I could load him – and he knew it.  Big white was well aware of the fact that he didn’t have to do what I wanted him to do and his efforts of distrust resulted in his victory.  I really understood the importance of low-stress animal handling, and was basically doing it everyday, but I was beginning to doubt my ability and skill level as a farmer. At least now I can look back and laugh, but at the time it had got to the point where some buddies were making fun of me.  I had shared these attempts with people who might actually have some helpful advice and one response was “well, I guess he’s gonna just die of old age.”  That one stung a little bit, but I’m thankful for it – because it stuck.  A voice inside me said “No. No, he won’t.  I’ll get him, one day I’ll get him and I will not give up”  I just didn’t know how…

If I recall correctly about a year went by.  A full year or so since I missed that initial first slaughter date and it did appear that big white was just gonna have to live here forever.  Man, he was big too.  We never ran out of grass the whole time and he just lived with the sheep, getting moved everyday and gaining weight everyday.  The typical standard weight for steers at slaughter is 1200 pounds live weight.  I gauged him to be every bit of 1800 pounds.

One warm evening when the days are nice and long I had finished work for the day and was just piddling around the farm in the cool of the evening when suddenly a thought came to me.  Lysondra was in town.  Lysondra is a good family friend.  She and my wife had met years before when they worked at the same restaurant in Hendersonville.  The service industry is something I have no experience with, but they really hit it off and apparently you can develop quite a bond amidst that fast-paced environment.  She had moved out of state and was visiting this evening with my wife and kids.  Lysondra is a real sharp lady, raised on Staten Island and grew up there in the 80’s; quick-witted and says what she means, she and my wife would have lots to catch up as it had been awhile since they’ve seen each other.  I also knew she’d keep my kids occupied because it’s all about family with those two.  For me at this moment it meant that I didn’t have to rush home to be with my family because they were occupied, and it was such a nice evening, I didn’t really want to leave anyway.  Piddling around thinking about what to do, realizing I didn’t have anywhere to be I said aloud: “I’m gonna go catch the steer”.

The flerd had been in the goat pen for a few days.  The goat pen was this little half-acre paddock that I built years prior when we tried our hand at meat goats.  It was this little section that wasn’t quite pasture and wasn’t quite forest, that lovely little mix of multi flora rose, privit, blackberries, and a bunch of other pioneer species that I wasn’t familiar with.  I had built a five-foot tall, 4”X2” welded-wire fence secured with T posts and let some goats have at it.  The meat goat venture ran its course and the farm was left with this cool little paddock in a transitional location between the main pasture and the woodline.  Normally, there was only about 12 hours worth of forage in there but I prolonged their stay by feeding hay for an extra day to add to the animal impact and lay down some more carbon.  It was worth it to keep that area leaning toward growing grass as opposed to forest, without having to get in there with machinery and rip all that brush out.  Livestock like to move, and they like to eat green grass when they have a choice, so I knew they would exit the goat pen with no fuss, but I was gonna throw a little curve ball at them.

A map of the pasture as it was on that fateful day.

I went and got the livestock trailer and set it up just outside the gate to the pen.  I put up a strand of temporary netting for their next paddock, and I even had a little sweet feed laying around I took with me.  Nothing was different except the trailer being in between where they were and where they wanted to go.  I opened the big back loading door and the small pedestrian door on the front passenger side and hid.  I went outside to the front of the trailer and laid underneath it on the ground completely out of sight from all the animals and waited, quietly.  The donkeys were the first to go through.  No hesitation to speak of, they went to the back of the trailer and kinda stared at it for a moment, then hopped right on and went right out the front door into the new paddock and began grazing.  All I could really see was a bunch of hooves scurrying along.  My point-of-view was fairly limited from underneath and as soon as the sheep watched the donkeys pass through unscaved and start eating, they soon followed.  It was fun to hear the flock scamper on the floor just inches above my head.  I was feeling rather proud of myself, so-far-so-good.  In the moment, my efforts at concealment were thus far paying off, but I had learned many times over not to get too confident.  At this point, Big White was not where I wanted him to be, and the scoreboard had him winning and me losing by a landslide.

My plan went something like this: as soon as he got all four feet on the trailer, I would spring up and close the pedestrian door, then dash to the back as quickly as I could and close the back door.  I layed there, out of sight, no movement, no sound and peeked out as I watched him start galloping back and forth in the paddock.  One thing these herd animals really don’t like is to be alone.  With the rest of the flock in plain sight, happily and calmly grazing along, all he had to do was walk through the trailer to cross the threshold.  That was the last option in his mind though.  He ran fast as he could all along the inside of the goat pen just looking for an alternate route, and I knew that he could jump fences because he’d done it many times in the past.  At 1800 pounds, my little goat fence wouldn’t stand a chance.  Right when I was thinking about all that he took a full fledged sprint straight toward the fence and I knew he was going to jump right over it and all I could do was sit there hidden and watch.  In addition, if he jumps over this fence and sees my lying under this trailer trying to be all sneaky, I’ll really have my cover blown.  It would just be another victory for the steer – chalk one up for him again.  To my amazement, right in the very moment when he would have jumped, he stopped.  He stopped and checked out the trailer, sniffing it and pacing behind it.  After he calmed down a bit, I could see his feet getting real close to stepping up there.  I could see he had his head in and was considering going in; there was hesitation, and I thought maybe he could smell me and I was adding to his suspicion.

I figured he was getting pretty stressed again. After that last episode, I thought to myself:  not having caught the steer is different than not having caught the steer and having him jump another fence, and then having to go fix it.  So, I decided to go back to the drawing board – maybe some other opportunity would arise and I’d have better luck.  I got up and walked toward the truck, all set to hook up to the trailer and move it out of his way when I said to myself: “You know what.  If he wants some damn grass he can walk through that thing and get it himself and if he hops another fence, so be it.”  I got about 40 yards away and sat and watched.  It was close to sunset by now and that little spot on the farm has great western exposure.  The peacefulness of the sheep and donkeys grazing in the cool air with a watercolor-painted sky was quite tranquil.  The ease only disrupted by big white still pacing back and forth in the goat pen looking for a way out, any way out other than through the trailer.  Just as I figured I better get the truck and let him settle, I was astonished to watch him suddenly walk right through the backdoor and straight out the front.  It was a decisive move, almost as if he shrugged his shoulders and just went for it.  I guess he got tired of watching all his compadres eating grass and felt he was missing out on the fun.  I was so relieved to see it happen, thankful to witness him conquer his fear and pass through, but it didn’t get me any closer to achieving my goal.

So now he is out with all the sheep and two donkeys, I let him settle down a bit after he started grazing and he looked perfectly content, all was calm.  He really had to pump himself up to go through the trailer, so I knew I didn’t have a prayer of getting him back on tonight.  Besides, it was getting dark and I would have to set up a whole new configuration to even try.  I headed back toward the barn, with my chin on my chest a bit feeling like I had lost yet another battle with the steer – a feeling I was too accustomed to.  On the way back I remembered the half bag of sweet feed and an empty feed bucket.  I eased back through the flerd with the sweet feed and they were so content nobody really paid me any attention.  I took a little detour to the donkeys who hang out together in the field.  They have been around the block on the farm, in fact the older one was here before me so I thought I’d give them a little treat just because I had the opportunity to do so and they practically never get any sweets.  I’m scratching their ears with one hand and feeding them with the other when low and behold, big white looks at me, smells the air and takes a step or two in my direction.  Quick and calm, I placed the feed inside the front pedestrian door, went to the back and closed the big door and sat off in the corner to see what would happen.  I put the feed all the way inside the pedestrian door as far back as I could.  If they wanted it they would have to step up in there and get it, not stand outside with their feet on the ground and stick their heads in. This would prove to make a big difference.

The donkeys practically followed me on the trailer, soon as I set the feed down they were on it.  The two of them shoulder to shoulder eating out of a bin in a corner creates a touch of a competition.  Healthy rivalry among the animals isn’t a bad thing and it worked in my favor because Big White was easily twice their size, but the treats were in short supply.  I was well out of the way back to my 40 yard spot to make sure no matter what happened, I wouldn’t interfere.  Sure enough, Big White followed his nose down there and looked in the trailer to see the two donkeys having a grand time eating what is essentially ice cream to livestock.

A couple key things happened next: first he stuck his head into the trailer, then he put it as far in the trailer as he could without stepping in.  He still couldn’t quite reach the feed, at least reach it and enjoy it comfortably with two donkeys in his way.  I worried that they would run out, I didn’t put that much in the bin, just a treat and if I ran down there and spooked them by trying to add more, I would risk blowing the whole thing.  I think the urge to have a couple good satisfying mouthfuls was enough to convince him, and considering he had just been on the trailer and nothing remotely bad happened, he had no reason to associate it with any danger.

My excitement, anticipation and heart rate were all on the rise.  Here he was with his whole head in the space where I wanted him, I’d never been so close. No noise, no people clapping and screaming, no chains banging on metal, none of the things you know would spook livestock, just a little bit of feed and me well out of the way.  Then it happened, he put his two front feet on the trailer.  I couldn’t believe it! So close!  I flew down there as fast as I could and I never made a sound (yes I’m bragging a bit on that one) careful to stay completely out of his sight path should he look up.  I positioned myself a few feet away, trying hard to remain calm, a lot could still go wrong here but then… yes!  He took a full step forward, all the way into the corner to get complete access to the feed while the donkeys had to wait their turn.  Now I am inches from him, he still doesnt know I was there and I’m face to face with his rump, which is as tall as I am.  It was really exhilarating, nearly a year’s worth of failures had all accumulated to this very moment, and I had to play it right, my one chance!  He was mostly in there but not all the way, two back feet still on the ground, how can I get him up there, and without thinking about it I slapped him on the ass as hard as I could and he jumped right on the trailer!  I had that door closed in the blink of an eye and nearly had what felt like a panic attack but with excitement.  I must have ran around that thing checking the doors and latches at least a dozen times.  With him loaded and the trailer secure I finally had him.  Having lost every previous battle, that evening I won the war.

The next day I called the abattoir first thing and happily reported that the steer that had been alluding me this past year was loaded and ready to go and could they please find an opening for me.  To my surprise, they had one the next day, so I filled a water trough for them and parked the trailer in the shade.  The donkeys would simply have to go for a ride.  The slaughterhouse has a great handling facility and when I got there we put them back on the trailer with no difficulty whatsoever.  When I got back to the farm, they went back in with the sheep and are still out there grazing right now as I write this.

As previously mentioned, most steers are finished at 1200 pounds live weight.  After they are eviscerated, the carcass hangs on the rail in a cooler for 10-14 days.  This is called the hanging weight, typically 60% of the live weight, typically somewhere around 700 pounds.  Then after the carcass is butcher, you end up with roughly 500 pounds of actual meat.  Another way to consider it is 40-30-30.  Forty percent skin, bodily fluids, hair, etc.  Thirty percent bones, and thirty percent meat.  When I went to pick up Big White he had hung on the rail at 1,020 pounds, 300 pounds over average.

This all happened about 8 or 9 years ago and since then I have loaded, moved, worked with and harvested many animals.  I’ve never had one that was that untrusting and fearful.  All the livestock I have since worked with display similarities at times but never to that extreme.  I’ve had a few old-timers tell me you always get one like that.  This makes sense if you think about it.  When you are around animals all your life and they are constantly coming and going, consider the one that was the most difficult, its bound to happen in life that some animals are easier to work with that others

I’m thankful for that steer.  Thankful for the lessons he taught me about low stress handling.  His hypersensitivities forced me to treat him gently and with great care, in a way he kinda taught me about trauma.  If I had chased him, or used cattle prods, or constantly yelled and scrambled at him I have every reason to think he would have been even more difficult to work with even more stressed.  I have no interest in making any animals’ lives stressful, just the opposite.  If the goal is to understand as much as we can about livestock and try and work with them to regenerate our lands, not depreciate them, and only in the end to transition them into food we serve our friends, families, and customers, they absolutely deserve the best possible life we can give them.  He taught me that I’ll never know what an animal wants more than the animal itself and so it becomes my job to observe and provide.

There is an element to farming that I think all producers experience in different ways and at different times.  A feeling of trying to control things you don’t have control over.  Sometimes it goes the way you want and you feel on top of the world, other times things don’t pan out and you have to succumb and show up tomorrow to try again.  Over the years, the more I remove my intentions, the more I try to let nature show me what it wants, the more I’m able to plug-in and achieve cohesion, the more success I have.  The animals are my greatest teachers, I hope it stays that way.

Thank you, Big White

Working with the Roots

By Greta Dietrich

In the southeastern United States, November is the time when we begin to gather the root medicine from our perennial allies. Midway through fall, as the days shorten and the weather becomes colder, first freezes die back the terrestrial parts of plants. After the living green dies away the energy of a plant flows into the underground organ we call the root or rhizome. Starches and carbohydrates and many other chemical components gather in a concentration in the root acting like a battery to assist the plant through the winter and ensure new growth in the spring.

There are optimal times throughout the year for harvesting all parts of the plant – the flowers, leaves, buds, seeds and roots. Some plants require several seasons to pass before they are ready for harvesting roots. Echinacea, purpurea for example, needs to have three years of growth, and Astragalus, membranaceus needs four to five years of growth. Only after these plants have had many seasonal cycles will their root medicine be ready. This is mostly because it takes several years for the roots to develop into large enough size and build up a concentration of medicinal constituents.

Deciding the best way to harvest a root is unique to the plant. Before harvesting, take into consideration if the plant that you have positively identified is native or a non-native species. Non-native are more sustainable to harvest because often they are more invasive and are endangering native species. If it is a native species check to see if it is an at risk plant. United Plant Savers is a great resource for educating yourself on endangered plant species.

Instead of wildcrafting native species, search out your local woodland farmers and support them. Do not harvest anything that is endangered or at risk.

After answering these questions for yourself, then decide if you should partially harvest a root, fully harvest it or leave it alone. A partial root harvest allows for some of the root to be harvested and replanted with the intention that the plant will continue to grow for years, creating a more sustainable relationship. This may be a great option for a plant you are trying to establish a large patch of and don’t want to cut into the population such as black cohosh (Caulophyllum thalictroides) or wild yam (Dioscorea villosa).

As an example, one can harvest part of a comfrey root and replant the rest. Comfrey (Symphytum officionalis), is easy to propagate from root. Half of the harvested root can be used to propagate new comfrey plants and used to replant in my garden, the remainder I will dry and use for salves.

figure 3

If I treat 6-7 comfrey plants like this I can get a good amount of medicine and a plethora of new roots for vegetative propagation for the following year. Deciding whether or not to harvest a whole root as opposed to partial root harvest depends on what your need is. Either way, inspecting the root when harvesting gives opportunity to make root divisions and stimulate new growth come spring. Harvest half to three-fourths of the root system for medicine and replant the remaining roots attached to the crown (see figure 3 & 4).

figure 4

By digging the root and separating the rootlets and buds and cutting up the root you can make clones of the root stock and enlarge your stand of that particular plant. Depending on the plant you could get anywhere between 7-20 baby plants or divisions off of a mother plant (see figure 5). The benefit of this is that you can bypass the process of seed starting which has many processes such as the time it takes to create mature plants. Planting from division you get the same characteristics as the parent. This is a great way to work with genetic qualities you favor and characteristics you like in a plant.

figure 5

Take extra care to properly identify the plant before harvesting. The lack of foliage may prove difficult to identify. Roots tend to overlap and inter-grow. Once I had a very well-meaning forager bring me a nice harvest of Japanese knotweed. The patch of plants had been properly identified and I happily set to work processing the freshly harvested roots. While cleaning tiny little rootlets that were growing in and around the main root system, little did i know i was removing poison ivy roots with my bare hands, which 48 hours later showed up as the worst poison ivy rash of my life. It is wise to follow a plant through several seasons for this reason to properly identify it. If this had been done with the knotweed, then certainly the jolly forager would have known poison ivy also grows in this patch with the knotweed.

Another thing to keep in mind is where you are harvesting. Steer clear of roadsides and around houses or fence lines where the ground may have been sprayed with harmful chemicals. If you decide to do a whole root harvest, then the plant obviously will not be growing the following year. This may be fine especially if the plant is an invasive species in your planting zone like japanese knotweed or kudzu root, or if you simply want to thin out an overcrowded area in your garden.

A digging fork is a great tool to use for harvesting roots. Use the sturdy tines to create a circle around the plant you wish to unearth. By gently rocking the digging fork back and forth around the base of the plant or root crown you can begin to loosen the root and get a sense of how deep it is and if there are any lateral roots. Stopping and using your hands to get a feel for how and in what direction the root is positioned is helpful.

As soon as you have harvested the roots , you will want to process them as soon as you can. Using a hose and a brush is very helpful in removing soil. I always have pruners handy to break up bigger sections and scissors to break up smaller sections. As soon as all roots are well cleaned, chop them into desired size as soon as possible because they harden very quickly as they dehydrate.

Root season is an active time for harvesting and processing. It is a rich time for both propagating and medicine making. Whether you are foraging or feasting, roots offer a bounty of food and medicine. Getting to know your local roots will connect you deeper to the natural world, and the rewards abound.

Native herbs of the Eastern United States can be purchased here, here and here.  Thanks for reading, and Happy Rooting!

All About Batteries

Batteries have become such a ubiquitous part of life that we often don’t give them much thought until they fail.  At that point, they’re an inconvenience, an unwanted expense, and to most of us a profound mystery. Yet they’ve brought so much accessibility to our lives that it would be difficult to imagine getting by without them.

Cell phones, power tools, laptops and tablets, medical and communications equipment, portable devices, and even vehicles all rely on some form of battery storage. And since batteries span a full spectrum of applications, chemistries, performance, and environmental impact, it can be difficult for a consumer to make a good—not simply convenient—decision when making a purchase.   

The common dry-cell battery found its way to market in 1896 and used a zinc-carbon and paste construction to replace earlier liquid solutions, opening the door to portable electric devices, most notably the flashlight, since it would work in any orientation. That first cell was essentially the plain-vanilla D-cell 1.5-volt general purpose battery still used today.  A single-use disposable, it served nearly a century no questions asked until we began to question the very fabric of our throw-away culture.  

The first dry cell appeared in 1896 and opened a world of new possibilities for portable electric devices

Curiously enough, several years after the National Carbon Company (predecessor of Eveready/Energizer) introduced the dry cell, a rechargeable Nickel-Cadmium (NiCad) alkaline battery was developed in Europe. Alas, it was a wet cell and relatively expensive, and so the technology didn’t find its way to U.S. shores until after the Second World War.

Following several decades of persistent research into alkalines, technological breakthroughs occurred beginning in the 1980’s when Lithium-Ion (Li-ion) and Nickel Metal Hydride (NiMH) chemistries were developed for satellites and specialty applications. Today, there is an impressive range of battery chemistries and constructs, seven in the Lithium family alone. But for the purpose of this blog, I’m going to focus on the most popular consumer rechargeables and single-use batteries common to specific devices because that’s what most people use.

What’s in a Name?

Let’s begin with terminology. What we commonly call a battery is actually a cell, or a single electrochemical unit that converts chemical energy into electrical energy. When two or more cells are assembled together, it becomes a battery, or group of cells.

The batteries that we’d typically use in our devices have positive and negative terminals and two internal components called electrodes—one cathode which carries a positive charge, and one anode to carry a negative charge. These are embedded in an electrolyte, a material that conducts electrons between the terminals. When the battery is installed and the device is turned on, an oxidation reaction takes place and electrons move through the electrolyte to exit the anode and power the device.

Because they’re often called storage batteries, there’s a misconception that batteries and cells “store” electricity. What actually happens is that they store energy in a chemical form, and when a conductor provides a path for electrons to move and do work, the process initiates the chemical reaction. In time, the reaction degrades the chemicals and they eventually stop supplying electrons. In a rechargeable battery, the electrons’ direction of flow is reversed during charging, reversing the electrochemical process and restoring the electrodes to their original chemical state.

A dry cell battery works through a chemical reaction activated by a load such as a light bulb or other working device

Primary batteries are single-use disposable units, the AAA, AA, C, D, 9V, and button/coin types familiar to us in many products from flashlights to cameras. These are by far alkaline or lithium batteries, though general-purpose zinc-carbon cells are still manufactured.

Secondary batteries are rechargeable and are usually device-specific, though secondary letter-size and 9V batteries that use NiMH and Li-Ion chemistries are widely available. (The most popular Li-ion cells are 3.6V but 1.5 volt cylinder sizes exist.)  They have largely replaced reusable alkaline batteries, a transition technology developed in the early 1990’s as a green option to single-use disposables.   

Other than determining by shape and size that a battery will actually fit in your device, there are other things to be aware of when battery shopping. Voltage output is indicated on the cell. So an AA configuration not only tells you that the cell is 14.5mm x 50mm cylinder, but that it has a nominal voltage of 1.5V. Coin and button-cell batteries use an alpha-numeric code, where the first two letters indicate the chemical composition and the shape, followed by four numbers indicating the size in millimeters, diameter by height.

Nominal simply means in name only. Actual voltage of an AA alkaline battery fresh out of the pack is about 1.6 volts. A reusable alkaline of the same size, 1.2 volts.  And an AA rechargeable NiMH between 1.2 and 1.25 volts. So how do they all work in the same device? Because the voltage of a single-use alkaline cell declines immediately as the battery discharges, putting it on par with the reusable and the NiMH, which tend to maintain their consistent voltage much longer under use. 

Battery capacity is measured in milliamp-hours (mAh) and may range from 900 mAh to over 2500 mAh depending on chemistry. A battery with a rating of 2000 mAh should deliver a current of 2000 milliamps for one hour. Though higher energy capacity batteries will generally power a device longer, high-drain devices like digital cameras will deplete an alkaline cell more quickly than it will a NiMH cell because of their high rate of draw. In comparison, the Nickel Metal Hydride cell can tolerate higher rates without exhausting the battery.   

Self-discharge rate is an important factor for devices that spend a lot of time waiting for use, such as a flashlight or smoke alarm. It’s also a measure of shelf life, as when stocking up for later emergency use. Power loss on standby can be fairly high in standard NiMH batteries—up to 40% capacity in a month. Hybrid NiMH batteries (marketed as pre-charged cells) do much better in this category, and Li-ion chemistries excel, along with standard alkaline batteries.  

Charging cycles refers to how many times a battery can be charged and discharged before its useful life is over. Alkaline batteries are generally not rechargeable (except for the reusable types) but NiMH cells can be cycled over 500 times and some Li-ion cells over 1000. Pre-charged NiMH batteries perform slightly better than standard NiMH cells.

Single-use batteries may be less costly initially but they take an environmental toll over time in that they cannot be conveniently recycled and are usually just discarded. Occasionally local recycling facilities may sponsor a hazardous household waste collection event where they can be turned in, or you can take advantage of the mail-in or take-back programs offered.

Rechargeable batteries are a better choice in that they are generally recyclable. NiCad cells are hazardous waste and must be recycled when they are spent. NiMH and Li-ion laptop batteries are non-hazardous, but can be recycled through local programs or through Call2Recycle outlets. Some button-cell batteries contain silver and mercury, but many are mercury-free and relatively benign. Regardless, these too should finish their lives in a recycling facility.   

One aspect of battery manufacture that doesn’t always get the attention it warrants is the necessary extraction of conflict minerals. Mining and mineral harvest are part of any manufacturing process, but the evolution of battery technology has increased the demand for materials such as lithium and graphite, and with certain chemistry types,  rare metals such as cobalt, nickel, and manganese. These are often mined and processed in developing and politically unstable nations, where worker rights and protections are meager at best. Certainly something to keep in mind when buying batteries, and certainly an incentive to maintain them properly to extend their useful life.

Mineral extraction includes the harvest of conflict minerals which are often mined in unsafe conditions

Choosing a Battery

If this were a discussion on batteries for electric vehicle design, factors like weight, size, and safety would be key considerations. Since those factors are already established in a laptop or flashlight or any other consumer device, a buyer should be comparing cost, capacity, charging cycles, and disposal in order to get the best value. NiCad cells, for example, have largely been replaced by NiMH cylindrical batteries because they don’t contain highly toxic cadmium and have a 40% greater energy capacity.     

From Encyclopedia Britannica 2007

In most cases, if the other parameters are satisfied, contrasting cost to cycle life offers a good yardstick for value comparison. For example a popular pre-charged NiMH 800mAh AAA cell is available for $10.49 a 4-pack, or $2.62 per unit. Another manufacturer sells standard NiMH cells with the same capacity for $2.08 per unit. Even though the cost of the pre-charged is $0.54 higher, their cycle life is nearly three times greater so they represent a better value over time.  

Charging Strategies

Proper charging and discharging practices are an essential part of maintaining the life expectancy of any type of battery. In normal use, a battery performs best when it’s not exposed to extremes of heat or cold, especially sub-zero temperatures. If you can schedule charging sessions once the pack has been acclimated to room temperatures, it’s better for battery health.

When NiCad batteries were more common, users were cautioned against the “memory effect,” or recharging after shallow discharges, which encourages that chemistry to absorb only the amount of energy it supplied during its previous discharge. NiCad’s, in fact, require a periodic full discharge and prefer a fast charge and immediate use to being cradled in the charger for days at a time.

NiMH batteries, and Li-ion’s particularly, share no such memory quirks. They can be recharged at any point in their cycle with no recall effects. They will, however, last considerably longer if they are discharged within the shallow end of their range before recharging. A good rule of thumb is a 30% discharge, with 50% acceptable. Deep discharges, especially under high loads, can reduce cycle life by half. Charge times for NiCad batteries can be as quick as one hour. The others need 2 to 4 hours to full charge, with slightly less time for reusable alkalines.   

The slab, block, prismatic, and pack style batteries found in cell phones, laptops, and other consumer devices are often Lithium-ion chemistries and come with dedicated chargers. Rechargeable cylinder style cells are similarly charged, or can be used in what’s known as an  intelligent digital balance charger which accepts NiCad, NiMH, or Li-ion cells (up to 20,000 mAh) and automatically adjusts voltage and charge rate to suit the chemistry of the battery.

A plug-in balance charger accepts a variety of battery chemistries and self-adjusts for charge profiles

When charging multiple batteries, avoid mixing different capacities and different brands, and try to maintain the same age cells in a simultaneous charge. The same practice should apply when using the batteries as well; consistency promotes better performance and longevity.

There is also a wide array of solar chargers on the market that provide a reliable source of power whether you have access to the grid or not. Compact windowsill chargers are made to supply energy to multiple configurations of NiMH and NiCad cells, and similar packages are available for older style reusable alkaline batteries too.  

Compact solar chargers are economical, versatile, and convenient

Borrowing from the outdoor recreation venue, foldable portable chargers provide greater wattage and work with many devices including cell phones, rechargeable lanterns, tablets, digital cameras and the like. More robust configurations with adapters will charge a variety of larger devices including compact power stations safely, with an assortment of voltages. 

Portable solar chargers can be used for a wide variety of devices

Reliable battery technology has brought us to a place unheard of even a few decades ago. Using it wisely is the responsibility of all of us if we’re to be educated consumers.  

On-Farm Plastic Recycling

From last year’s Cooking with Food Waste workshop to the upcoming installment of the developing Waste Not series, Living Web Farms is making a point to not only reduce waste, but  help change the perspective on waste all together.

There is no waste in nature.  As agriculturalists, there is great importance in studying farming practices that mimic natural systems.  However, as farmers, it is also important to be honest about certain non-natural materials, particularly plastics, and their role in productive modern sustainable agriculture.  Plastics are lightweight, resistant to biological decay, mostly translucent, tough, and most of all, inexpensive.  On the farm we use HDPE containers, polystyrene starting trays, PVC piping systems and polyester floating row covers – just to name a few examples.  It would be hard to imagine a better suited material than translucent LDPE film for greenhouse coverings; its low cost allows more farmers access to year-around food production.  In this sense, plastics could be said to have a democratic “leveling” effect – and, herein lies the problem – agricultural plastics have become so prolific, and so cheap to replace that many farmers and municipalities have implicitly agreed there is little incentive to recycle them when their useful life is over.  Without recycling opportunities, the most responsible farmers are left to landfill their plastics. Others bury it on site, or worse yet, burn it.  Still, for others, spent agricultural plastics are often piled up and neglected, exposed to UV light and weathering where its size is reduced to unmanageable bits.  Perhaps what is most offensive here is our newfound reliance on materials made from petroleum stocks that are formed over millennia, used only for a few seasons, and left behind to degrade for possibly yet another millennium.

For nearly three years the LWF biochar crew has been exploring on-farm plastic recycling.  Our doe-eyed naivete humbled and hardened over years of experimentation; Working mostly in fits  and starts, what began as a catch-all attempt at processing a wide range of consumer plastics ultimately had us finding our niche at the intersection of contaminated agricultural plastics and biochar production.

Preparing aging drip tape for on-farm recycling

Nutrient Cycling

Advocates of a circular economy often describe a dividing line between what they call ‘organic’ and ‘technical nutrients’.  Organic nutrients are materials defined by those made from renewable feedstocks and their recycling is governed by biochemical processes – think timber, biofuels or natural fibers for example.  A naturally dyed cotton tee shirt can be safely and easily composted whereby it’s nutrients are returned to the soil.

Circular Economy System Diagram from the Ellen MacArthur Foundation

Technical nutrients are materials synthesized from non-renewable materials such as glass, aluminum, steel, or plastics.  Ideally, technical nutrients are those that can be continuously recycled without losing integrity.  In circular economy models this is realized through leases or refurbishment buyback programs, where products and their various ‘technical nutrients’ are returned to the manufacturer when their useful life is over.  On the farm, technical nutrients can be thought of as those that can not be cycled via organic processes – or those that must be repurposed, recycled, incinerated or landfilled when their useful life is over.

This distinction between technical and organic nutrients may seem very mundane – but there are important implications in making these distinctions at home and on the farm.  A polyester (technical) and cotton (organic) blend tee shirt CANNOT be responsibly composted at the end of its life.  The authors of Cradle to Cradle: Remaking the Way We Make Things warn us about these ‘monstrous hybrids’ of inseparable combinations of both technical and organic nutrients.  Coated to-go coffee mugs and PVC/paperboard blister packages are common examples.  Wax-coated produce boxes and synthetic ‘latex’ painted plywood are examples of monstrous hybrids one might find on the farm.  Lacking foresight, something resembling a monstrous hybrid may be created too – for example, where tangled nylon tomato support strings become frustratingly tangled among the vines, or used LDPE film mulches become contaminated with dirt and moisture beyond the point where conventional recyclers will accept it.

The gardeners at Living Web use durable woven polypropylene landscape fabrics for weed control on specific row crops.  Rolled up gently at seasons’ end, and stored away from UV light these fabrics can be expected to last three to five years – at which point these aging fabrics must be removed before their breaking point is realized.  Otherwise they will begin to fray, leaving behind strands of the inorganic material, which become increasingly smaller and impossible to remove – effectively creating a ‘monstrous hybrid’ out of our soils.

Woven polypropylene weed barrier, reusable for no longer than five years

Reduce, Reuse, Repair, Repurpose, Recycle, Remove

Farmers wishing to reduce their plastic footprint and eliminate pathways to pollution should have a management plan for each type of plastic material used on the farm.  It should be simple and for many will sound very familiar.  A management plan should include provisions to:

  • Reduce future purchases of new material.
  • Reuse existing new material to the extent that it remains safe and effective.
  • Repair existing material when possible, to further extend its useful life.
  • Repurpose existing material when it has exceeded its useful life for its original purpose, so long that it remains safe and effective for its new purpose.
  • Recycle existing material when it is no longer useful in its current form
  • Remove from circulation the material that is no longer useful, cannot be repurposed and longer safe and is not able to be recycled.

Let’s look at few examples:

Example 1: Polypropylene Weed Barrier

  • Reduce: Prioritize robust mulches from organic materials.
  • Reuse: Gently remove as soon as possible at seasons’ end.  Further extend life by removing loose dirt and storing dry and under cover.
  • Repair: Fuse tears and frays by melting ends together with a gentle flame.
  • Repurpose: Save short sections for other seasonal projects.
  • Recycle: Although it will likely be very challenging to find a recycler to accept the material, your chances are greater by thoroughly removing dirt and water before tightly bounding.  Reach out to a local extension agency and see what recycling services are supported in your area.
  • Remove: All fabric should be removed from circulation after a field-determined maximum lifespan (five years for us), or when material begins to tear easily and frayed ends become excessive.

Example 2: LLDPE Drip Irrigation Tubing

  • Reduce: Use non-plastic or more permanent irrigation techniques when feasible.  Purchase robust and reusable 15 mil drip tape when replacing spent lower quality drip tubing. 
  • Reuse: Gently remove at seasons’ end, flush if necessary and store clean and dry.
  • Repair:  Inspect for visible damage upon removal and installation. Routinely inspect for leaks throughout the season.  Keep repair couplings accessible to field crew.
  • Repurpose: Heavier mil drip tapes are tough and allow for many creative uses of short sections.
  • Recycle: Until very recently there were markets for used irrigation tapes that were cleaned and baled separately from mulch films.  In our own on-farm recycling trials, drip tapes have proven to be one of the best, most consistent and easiest to work materials.
  • Remove:  Replace aging tapes with higher quality material when leaks appear more consistently and repairs become prohibitively expensive.

Repurposed drip tape

Small-Scale Recycling

Recycling – turning used products that would otherwise be discarded as waste and turning them back into useful products – is a complex system of processes with multiple steps, each with its own nuance and challenges.  A complete consumer plastics recycling system includes means for Collection, Sorting, Processing, and Forming.  On a municipal scale these steps are typically handled by different agencies – collected plastic is sorted and baled at the recycling center, sold to a processor, who then markets the chipped or pelleted raw material to a manufacturer.  Our initial on-farm recycling efforts were an attempt to handle all of these processes on our own.

These early efforts were largely inspired by the machine designs from Precious Plastics.  Originally a design-school project by dutch artist Dave Hakkens, Precious Plastics has grown into a global network of young and enthusiastic multi-talented plastic-waste problem solvers.  At the heart of the movement are open-source plans for mostly DIY low-investment recycling equipment, including a shredder, injection molding and extrusion machines, and various adaptations on compression molding machines.  An active online community offers troubleshooting help along with encouragement and advice of all sorts.   Nowadays, the precious plastic mission has expanded in scope; included among their offerings now are upgraded semi-industrial machine plans and an online marketplace dubbed the bazar.

By the end of the summer 2017 our crew completed building slightly modified versions of the V2 shredder, injection molding and extrusion machines.  The crew’s tenacious fabrication skills combined with a bit of junkyard savvy helped keep fabrication costs extremely low.  We were ready to begin experimenting.

The author, posing before a demonstration of our precious plastics recycling equipment.

Farm staff and families were asked to bring us all of their consumer plastics.  Quickly thereafter sorting, de-labeling, washing, shredding, drying and cataloging plastics nearly became a full-time job.  Each step had its own challenges, and it was quickly becoming an overwhelming effort that was taking away too much from other responsibilities.  After some brief experimentation with PET (#1) and polystyrene (#6) our initial broad collection efforts were quickly limited to only HDPE, LDPE (#2, and #4) and some polypropylene (#5).  Even then, reliably sorting polyethylene from polypropylene and subsequent cleaning of equipment after switching between polymers was proving too cumbersome.  The following spring, a friend and delivery driver for a local dairy helped us by collecting used, rinsed-out HDPE milk jugs from area restaurants – finally providing for us a steady supply of material that was well-suited for the capabilities of our machines.

Remembering the monstrous hybrid – One of our first hurdles was finding a reasonable way to remove paper labels from hundreds of milk jugs.  We attempted solvents, applying heat, scraping and some combination of all three before ultimately settling on cutting them out entirely prior to washing and shredding.  Shredded milk jug flakes were laid on screens and allowed to dry overnight before storing for later use.  Working within the limitations of our smaller machines, suitable injection molds were designed and fabricated by our incredibly industrious biochar crew.   Meanwhile we continued to collect brightly colored HDPE laundry and shampoo bottles when offered.  A combination of modest amounts of colored flakes with the translucent white flakes from milk jugs yields fascinating swirl patterns in injection molded products.

HDPE “Project Boxes” Injection molded at 180/185C


Fruit Bowls, black ones formed via extrusion of shredded drip tape at 120/126C

Precious Plastics is doing important work and has rightfully gained the attention of an international audience.  Where plastic products are generally thought of as mass-produced and cheap throwaway items, the community at Precious Plastics is helping change the narrative about waste.  By empowering people around the world to craft unique and beautiful products on machines they can make themselves, others are beginning to see plastic waste with an entirely different perspective.  Our machines are now used almost exclusively for demonstrations.   For children, a demonstration is a chance to watch trash turned into unique toys. Kids are shocked to learn that the material from a single one-gallon milk container is more than enough for one injection-mold full-size drumstick. For many adults there is a realization of the amount of work that goes into modern recycling systems.  The job is far from over when the recycling truck pulls away from the curb.

We have never bothered to offer products for sale.  The labor requirements of running our machines is way too high.  And, although usually a point of pride, our machines are a little too junkyard-sourced.  We have always been uneasy about the amounts of energy involved.  Naively, we jumped in without much consideration for generation of waste water and microplastics with our low-tech processing equipment.  After some time, we began to question if the work we were doing was even tangibly helpful at all – even after China rattled the global recycling industry by banning imports of mixed plastics, regional markets for recycled HDPE do still exist.  However small our impact, in some ways, our work with clean HDPE served to divert material away from professionals who could do the job better than us.

To be clear, our failure to achieve a reasonable economy is not indicative of the entire Precious Plastics community.  Many in developed countries have persisted and developed fantastic niche products.  In developing countries, where plastic pollution is much more apparent, these kinds of low cost accessible machines offer real opportunities for entrepreneurs to clean up waterways while making something beautiful.  However, on our farm in our part of the world, it was becoming apparent that in order for us to move forward with our work in plastics recycling, we would need to come up with tailored solutions that address our own plastic waste and use much less energy doing so.

Finding Our Niche

Those who have followed us know that we speak often about biochar.  We’ve talked a lot recently  about various small scale production methods, inoculating biochar for use in the garden, and even touched on water filtration applications for homemade biochar.  And even though we’ve been relatively quiet about it, we are still producing biochar with our farm-scale system.  At our peak production our ‘triple-retort’ system is capable of manufacturing about ten cubic yards of biochar/week.  From 1200 lbs of sawmill waste, a single batch yields about 400 lbs of crushed biochar along with some 40 gallons of wood vinegar, 5 gallons of ‘pyrolysis oil’, and a considerable amount of heat from the combustion of excess syngas.  Wood vinegar and oils in the form of raw condensate are stored in second-hand caged HDPE containers known as IBC totes.  Over time, tars settle to the bottom of these containers where then clarified wood vinegar can be decanted off the top.  We had accumulated a considerable amount of wood vinegar in the years before modifying our system to include a condenser bypass.  Scaling up our wood vinegar field trials means a considerable amount of tar-stained IBC totes are left behind.  Suffice to say, these tar-stained HDPE totes are too contaminated for conventional recyclers to accept.

Products of wood waste pyrolysis

Simply put, biochar can be produced when wood, or some other carbonaceous material is heated in the absence of oxygen.  This process – known as pyrolysis – requires heat to get started, though after some time it will become self-sustaining.  Gases created during pyrolysis can provide the energy to continue the process.  In our system, sawmill waste is loaded into large oxygen-limiting stainless steel containers known as retorts.  These retorts are indirectly heated, starting at ambient temperature and over the course of a few hours reaching a critical point at which a transformation of the wood waste begins.  Some solid material is left behind and carbonized into biochar, while the same time, through destructive distillation gases are released from the heated wood.  This blend of gases, known as syngas, exits through a series of pipes where then condensable gases can either drop out as liquids or be directly combusted to provide heat. Through a corresponding series of channels and valves, heat from the combustion of excess syngas can be directed throughout our system and used to start another batch, heat or water, or in our case, recycle plastic.

Process time compared to internal temperature of wood in the retort.  A five hour window of opportunity for recycling happens between 400 and 900F.

Moving forward with recycling contaminated IBC totes would present a series of challenges.  Preparing totes for molding would require removing as much sticky tar as possible from the material prior to shredding.  What we found to work best is a process involving removal of the totes from their cages, cutting the bins into strips and laying them out in the sun for weeks.  The sun-baked tar is easily scraped off during the shredding process.  Still, we needed a larger shredder to accommodate the thicker material.  We found luck when a neighboring business sold us a decades-old salvage Weima-WL 6 wood shredder, where then we had it adapted to a tractor PTO drive.  Today, shredding the material still remains our biggest challenge.

Our early product designs sought to mimic the versatility of plastic lumber.  We built simple steel molds and a large custom press and trials began shortly after.  Molds were filled with HDPE chips, loaded directly into one of the retort chambers and indirectly heated until reaching a predetermined optimum temperature.   These trials were largely a guessing game at first – and failures were often demoralizing.  Plastic would overheat and offgas noxious fumes.  Molds were unevenly heated resulting in burned and unmelted sections on the same piece.  Even when successful, the shrinkage rate of cooling HDPE was too apparent in the longer board-length molds, causing our finished product to take on a twisting, uneven quality.  Nonetheless, we persisted, ultimately concluding 195C was the optimum temperature for compression molding our tar-stained flakes.

The crew addressed the problem with uneven heating by constructing a suspended interior chamber, which could drop into the retort and keep molds suspended above and isolated from overheated surfaces.  Air circulation throughout the chamber is maintained with a junkyard-sourced furnace blower.  This blower remains powered on throughout the entire heating process. A small setpoint-controlled exhaust blower is utilized to draw in ambient air when necessary to help maintain a more precise internal temperature – in this way, we have both coarse and fine methods for temperature control.  Built as a prototype at the time, this ‘convection heater’ has proved effective and is still used today.

Cutaway diagram of the suspended convection heater. Yellow line represents high temperature gases from combustion chamber to water heater. Red lines indicate circulating air, limited to 195C.

Prior experiments had shown that our method for compression molding HDPE would not produce usable plastic lumber without considerable post-processing – planing, shaping and sanding – all processes that create a demanding amount of fine plastic dust.  Additionally these trials proved that a substantial amount of pressure would be required for adequate compression.  By the end of 2019, we had built a new, exceedingly robust stainless steel mold and corresponding 20 ton press. Our tree planter mold would handle 28 pounds of HDPE flakes and fit snugly inside our process-heated convection oven.  What followed were yet another series of increasingly smaller, but seemingly endless demoralizing losses – we had to build the press even stronger, modify the mold to include a removable bottom, and locate suitable release agents all while continuing experiments with optimizing temperature and residence times.  By spring of this year, after nearly a dozen failed attempts at complete tree planters, we had finally dialed in our process.

At ¾” thick, these 18” tall hexagonal shaped tree planters are robust and, in my opinion, quite attractive.  Heavy walls and non-structural applications mean we can accommodate contamination to a degree that other more precise molding processes could not.  At 28 pounds, we can process a meaningful amount of otherwise non-recyclable plastic – a scale that matches nicely with our stock of material and available process heat.  Labor demands are much lesser now during molding and post-processing, but remain high during shredding and washing.  Future work will seek to improve on this, and potentially open the door for molding with alternative materials – including LDPE films, and woven polypropylene bags and mulch fabrics.

Compression molded tree planters. A small amount of colored flakes makes for fascinating patterns

Planter mold detail

In Defense of Downcycling

In the fall of 2018 we held an open-house style workshop showcasing our work with plastic recycling.  This was right around the time when we were just beginning to experiment with compression molding with biochar process heat.  One of the attendees, a recycling industry professional, spoke of a company in the midwest USA that was accepting lower grade agricultural mulch films for recycling into standoffs for interstate guardrails.  As someone who commutes via interstate to an agricultural community, I’m often reminded of this comment – a business owner had found a use for all that dirty black film – not in making new film, but in making something entirely different – something downcycled.   Downcycling – normally the bane of plastic pollution activists – in this case was the solution.  In our case too, our contaminated IBC totes would never be accepted by conventional recyclers forced to compete in quality with virgin material.  Downcycling is the only kind of recycling we can do with our expertise, on our shop-made equipment.

A defense of downcycling should not be confused as a defense for the proliferation of single use plastic – What else comes to mind is the absurd distance this lightweight, non-dense material travels to make this transformation. Shipping our plastic waste to China, only to be returned as more single use plastic was an absurd system.  It goes without saying we should do all we can to eliminate unnecessary plastic.  At the same time, we can be honest about the productive and democratic benefits of durable plastics in our homes and on the farm.

A year later, towards the end of 2019, another visitor to the shop spoke of Dominican locals who would harvest beach plastic and gently heat them while pressing them into blocks.  Where others would carve driftwood figurines to sell to tourists, some were beginning to use these mixed plastic blocks as raw material instead.

In my humble opinion, at the time of this writing,  those in developed countries wishing to pursue DIY recycling for genuine environmental reasons would do well to be like these Dominican innovators and keep it local and small.  They should look to the ideas of the midwestern USA innovators and maintain a narrow, focused approach.  And, like both of them, they should prioritize working with conventionally non-recyclable materials.

Questions, Comments, Criticism, Compliments? Send an email

  • Dirty IBC totes - no longer conventionally recyclable

Making Fish Sauce, Fish Fertilizer, and Garums

By Meredith Leigh

The earliest evidence of fish sauces, or garums, dates back as early as the 3rd century BCE, made by ancient Greeks, and much speculation exists regarding whether the practice traveled from the shores of the Black Sea to the many other regions where garums are found, or if people across the Mediterranean, Asia, and elsewhere spontaneously developed their method for similarly preserving fish, without the help of trade. Modern day Tunisia, in North Africa, is where some of the oldest evidence of production can be found, in old garum factories carved from limestone, which would date to Carthaginian reign. When the Roman Empire took over, and sprawled across the Mediterranean, much of Europe, the Middle East, and Central Asia, culinary traditions spread with it. However, this doesn’t explain the origins of Scandinavian fish sauces, or garums found in Indonesia. What is certain is that where fish were abundant, fish sauces were the primary means of preserving and deriving maximum flavor and nutrition from fishery resources.

Fish Sauce varies in its chemical composition and flavor depending on where in the world it is made. Variations can be due to the fish available, the preference of the people making it, as well as climactic implications. Versions of fish sauce can be found in numerous countries, identifiable by their distinct names:

Indonesia: kecap ikan
Thailand: nam pla
Philippines: patis
Japan: shottsuru
Vietnam: nuöc mâm
Malaysia: budu
Myanmar: ngapi
France: pissala
Greece: garos
Iran: mahyaveh
Pakistan: Colombo-cure
China: yeesu
Korea: aekjeot

Fish sauce everywhere is just fish, slowly hydrolyzed, or broken down with water, by proteolytic (protein-digesting) enzymes. These enzymes come from the fish viscera (innards) and muscle tissue, as well as enzymes from microorganisms that may have been living on the fish. All animals have endogenous, or internally originating enzymes that aid in the digestion of their flesh. These only come in handy when the animal dies, and a process of autolysis, or an organism digesting itself, begins. No matter what fish sauce you’re interested in, you’ll find the common ingredients of whole fish, water, and salt. The fish and its internal organs and tissue provide the enzymes, and the salt offers stability by excluding harmful microorganisms that may spoil the product before autolysis can digest the fish.

Thus, the production of fish sauces the world over includes a mosaic of approaches to these basic ingredients, each method seeking to balance enzymes with salt as their palettes and climates allow. The ratio of these two ingredients within the context of temperature and time is what produces the lively variation in flavor, smell, stability, and overall character in garums everywhere. Analyses of almost 50 different fish sauces from the Phillipines, Southeast Asia, and Italy found salt contents ranging from 10-30%, overall protein content varying widely, and chemical and biological composition being similar, yet distinct from sauce to sauce. Think of it this way: there are many animals in the world which we call “fish”, but the species, shapes, colors, and other characteristics differ fantastically within their kingdom. It is as glib to generalize fish sauces as it would be to broadly generalize fish. What we can say is that they are fishy, nitrogen rich, and probiotic, to varying degrees and delights. Analyses of different sauces found 39 microorganisms representing 11 species of bacteria, 1 yeast, and 3 filamentous fungi.

Traditional fish sauce production in Vietnam

A more traditional approach might unfold as follows: Once the ingredients are mixed, the fish is fermented in concrete vats for 9 months at temperatures between 30-37C/ 86-98.6F. The liquid, known as “liquamen” is captured then aged 3 months. Some cultures flavor the liquamen as it ages, with spices favored in the region. The residue, or “allec” from this initial extraction is often leached 2-3 times and mixed with brine to produce sauces of varying lower qualities, which are usually blended with various amounts of the primary extract. The final residue of bones and sludge is used as a fertilizer.

In the oldest accounts, these varying quality sauces were associated with status. Liquamen from the blood and guts was called “haimation” and considered most valuable, whereas the pastes made from the allec were relegated to lower classes. This may sound strange, but fish sauce was so valuable in the Roman Empire that amounts as much as one gallon could be traded for nearly a ton of wheat. This is likely due to the fact that it was so full of tasty umami, but also because of its important nutritional qualities. Research in Asia on the nutrient density of fish sauces has shown that they can contain significant levels of nitrogen, mostly in the form of essential amino acids. This means that consumption of just 40mL/1.5 ounces of fish sauce in a day can account for almost 8% of an individual’s needed protein.

Most traditional accounts call for a ratio of as little as 1.5 to as high as 4 parts fish for every 1 part salt. Higher salt contents are likely attributed to regions with warmer temperatures, as more heat would encourage microbes that may outcompete proper enzymatic reactions.  Salt content in garums depends on how long the makers want to ferment, seasonal temperature flux, and time of year.

The type of fish varies, too. While most fish sauces are made from small fish like anchovies or sardines, larger sea fish are also used. The recipe included for this post uses mackerel, not an uncommon fish for garum. Most fish sauces are made with saltwater species, however there are accounts of ancient people using freshwater species from the Nile.

Modern adaptations of garum traditions are where fish sauces are being liberated. Far from falling into a strictly Asian culinary category, the sauces are being realized for their usefulness across the flavor spectrum. Chefs at world famous Noma are making garums from grasshoppers and bee pollen, and modern chefs worldwide are using garums in soups, vegetable pickles, and sauces. Because the flavor profile from such varying garums differs so much from the more traditional or familiar fish sauces,  they provide the perfect umami kick behind the dominant flavor in the food.

Like many ferments in modern kitchens, garums are experiencing a revival, and in the excitement of rediscovery, there is the urge to hasten processing, and modify. One way of recasting the fish sauce process has been the popularization of using the mold koji (Aspergillus oryzae) as the enzymatic catalyst for autolyzation, which can reduce the need for fish viscera in the recipe, and also speed the production. If you’re unfamiliar with koji, you can learn more about it, and how to grow it yourself in my workshops on “Koji in Every Kitchen” as well as “Making Miso, Tamari and Soy Sauce (coming soon to our video archive).” Makers pairing koji with fish trimmings for their fish sauce can create garums absent of innards, using instead just the fins, bones, heads, and meat, and still achieve proteolysis, because koji possesses the enzymes to do the job, and do it quickly. With the power of koji comes the ability to further play with temperature and salt. Paired with the technology of incubators and other control devices, the evolution and variation of fish sauces advances and telescopes with an ever-quickening pulse. As you craft the fish sauce, here, you will jot your own record in the ancient tablet of garum stories. A messy, smelly, mysterious and wild effort oddly organized by a common quest for concentrated deliciousness.

Homemade Fish Sauce (or one approach, at least)

For this sauce, I purchased two whole mackerel, and filleted them. My family and I ate the filets smeared with miso and pan-fried, but the rest of the fish- bones, heads, eyes, guts, and fins, went to this sauce.

1 lb./500g mackeral parts

4.25oz/120g pearl barley koji (either purchases, or home grown- see our “Koji in Every Kitchen” or “Making Miso, Tamari & Soy Sauce Workshops for more info on Koji)

14oz./400mL non-chlorinated water

3/5 oz./100g kosher or non-iodized sea salt

Fish parts, koji, water, and salt are all you need to make a fast-tracked DIY fish sauce.

Cut the mackerel pieces into roughly 1-inch pieces and place in a bowl. Crumble your koji and place it in another bowl. Measure the salt and set aside. Measure the water and have it ready.

Mix everything well.

Sterilize whatever jar or jars you’re  using for the fish sauce. I find it easier to fill the jars with even amounts, and then mix the ingredients, rather than mixing everything and then trying to slop it into my jars. You will want head space in the container, so think about that beforehand. I split this recipe into two-quart Weck jars, to ensure I had enough head space in each. Place each jar on the scale and fill them up. In my case, each jar got half of the mackerel pieces, half of the salt, half of the koji, and half of the water. Once the jars are filled with their respective ingredients, mix the contents thoroughly with a wooden spoon.

Seal the top of the mixture to minimize oxygen

Next, encourage a piece of Saran Wrap down into the jar, snugly on top of the sauce. Trim the edges and ensure that the sauce is covered by the plastic. Place the lids on the jars. If the seals are removable, remove them, as you will want gases to be able to escape as the sauce develops. I put the glass lids of the Weck jars on with the clips but left out the rubber sealing rings.

Label the jars with the type of fish used, the percent salt (in this case, 20%) and the type of koji. Place the jars into an incubator set to 98-100 degrees Fahrenheit. Allow to ferment for a minimum of 10 weeks before you begin tasting the results. Sample the liquamen to taste. If you want to age it further, return the jars to the incubator. If you want to decant the solids, do so, then bottle the liquamen and consider aging it for 2-3 months in a cool, dark cabinet or cellar. You may choose to add chiles, spices, or aromatics during this aging phase.

After one week. You won’t see much degradation of the fish pieces in the first 3-4 weeks. Don’t worry. Keep going 🙂

Note: Once you’re ready to decant the liquamen, be sure to use your residues or “allec” as well. If you’re not into making fish paste, use them in the compost pile or on the garden. Hydrolyzed fish protein is excellent food for beneficial soil fungi.

Storage: Your fish sauce should have stable water activity, due to the salt content of the recipe. As such, it will not need to be refrigerated, however you may choose to refrigerate it to cut down on the smell in your kitchen, and to keep it more stable. Add it by the drop to enhance soups, dressings, vegetables, and more.

Kitchen Allies

By Greta Dietrich

Plants are intrinsically woven into our existence and have been throughout time.  All cultures and histories have depended on plants for survival, for nutrition and healing.  Many modern kitchen herbs have originated from other parts of the world and are not native to Western North Carolina.  Their uses and stories have been shared between cultures and passed down through generations.

Many of these herbs are in our kitchens right now and still used today much in the same or similar ways as our ancestors.  Each plant holds a unique story reminding us that healing is accessible and begins right outside our door.  The human/plant relationship and intertwined histories are essential wisdom that is vital to preserve.  By bringing the green world into our kitchens we broaden our connection with the natural world and deepen our relationship to our own healing and health.

The herbal allies mentioned here are easily found at any grocery store.  Without even knowing it you may have already been integrating many of these herbs into your culinary pursuit.  A reintroduction to these plants may be revealing as to the spectrum of healing they may offer; sometimes we just need a reminder of the abundance of what we are already acquainted with.

These common herbs, many of which belong to the mint family, can be easily grown and very adaptable if you have the space.  If you live in a city or apartment and do not have the space to garden, try container gardening.  If that is not realistic, try a community garden or CSA (community supported agriculture) or your local community co-op.  Consuming plants grown in your bioregion (locally grown) have a rich phytochemistry of active constituents specific to that place they grow.  The specific ecology of these locally grown plant allies can aid the body in its adaptability and immune function.  Get to know these plants and they will be allies.  Growing your own herbs and/or learning to wild forage is good practice in sustainable health and  preventative medicine.

Garlic: Allium sativum

Garlic is native to Central Asia and Northeastern Iran. Garlic has been found in ancient Egyptian tombs, Greek religious temples, and it has been mentioned in ancient Traditional Chinese and Ayurvedic materia medica.  It has been prized for its medicinal uses for 5,000 years.  This classic staple, also known as “stinking rose”, has been used around the world on every continent for thousands of years.  Our ancestors used it often as a blood cleanser and anti-parasitic,  with reference to its ability to increase stamina in athletes, soldiers and the working class.  Its odiferous qualities can be contributed to the strong concentration of sulphur compounds.  The medicinal benefits of its culinary uses can be enjoyed on a daily basis to heal and increase immunity.  As an herbal ally it acts as a circulatory stimulant, which aids the heart in moving blood through the body and tissues, while also reducing cholesterol.

Garlic’s immune modulating actions refer to its ability to enhance the body’s ability to create natural killer (NK) cells.  The antimicrobial and antiviral actions of garlic have been shown in studies to be an anti-inflammatory powerhouse.  Similar to the action of antibiotics, garlic acts as an immune stimulant and also decreases pathogens in the body without killing or modifying the gut flora.  Lastly, but certainly not least in it’s repertoire of actions on the body,  garlic is a stimulating expectorant.  An expectorant aids the respiratory system in releasing mucus and phlegm, acting as a stimulant when lung congestion is present by assisting in the release of mucous through the action of coughing.  Garlic is a sure ally during cold and flu season.

Taken daily as a tonic, garlic is a beneficial plant with a broad spectrum of uses.  You can do this by adding it to meals.  It is suggested that upon mincing garlic, let it sit after chopping on the cutting board for 15-20 minutes to maximize health benefits.  This “resting” period for the garlic activates an enzyme called Allicin which boosts the immune system.

Finer chopping yields more allicin, which is responsible for its antibacterial and antifungal actions.  It is considered preventative for heart health, diabetes, and immune support.  It commonly has innumerable applications to be used in food.  The addition of garlic as a daily condiment when used fresh, sautéed, fermented or as an infused garlic in honey, is a great way to use garlic into your diet for additional health benefits.

Garlic is an easy and rewarding crop to grow at home either in containers or in your garden.  Garlic is planted in fall or early winter and harvested in mid summer.

Thyme: Thymus vulgaris

This ancient culinary herb is a perennial native of Southern Europe and Western Mediteranean. There are around 300 varieties of this very aromatic plant. Thyme is a member of the mint family as well. The scent of thyme is characterized by the phenols Thymol and Carvacrol. The name originates from the Greek word thumos meaning courage.  Warriors and knights alike would wear sprigs of thyme when entering battle, as it was believed to give them added strength.

An infused honey can be made by harvesting the vitamin A and C rich sprigs in the spring before flowering.  It is handy to have on hand by fall to aid in treating coughs.  Thyme can be utilized through steam inhalation to treat upper respiratory infection.  As a tincture, it can be taken internally for its antimicrobial and antibacterial actions.  Thyme makes a wonderful infused vinegar used to make salad dressings or as a tea.

Thyme is one that is easy to grow, and I have found it is forgiving.  No matter the size of your garden, there is room for thyme.  It also grows well in pots.  You can grow easily from seed by cuttings or layering in a rich well draining soil in spring either in pots or directly in the soil.   Harvesting can be done throughout the entire growing season.

Rosemary: Rosmarinus officinalis

Rosemary is a mediterranean shrub and a member of the mint family.  Medicinally it is used as a mental stimulator, circulatory stimulant, anti-microbial, stimulating/relaxing Nervine, and as a treatment for fungal infections.  As an evergreen shrub ( in warmer climates) with needle-like leaves, rosemary has a reputation as an herb for remembrance.  The scent is a deep robust lemony pine woodsy aroma, refreshing to the mind.  Rosmarinus means “dew of the sea”.  The ancients revered this herb for strengthening the memory.  Rosemary was traditionally worn by brides in their hair so as to always remember their families, and the dead would be buried with it so as not to be forgotten after they were gone.

As the ‘memory’ plant, or ‘remembrance’ plant, has approached present day, research has shown that the essential oil of rosemary aids in short term memory.  The blend of rosmarinic, acid, carnosol and carnosic acid helps with oxidative stresses in the brain.  In the scientific community there is recent interest to further study this plant for all of its cognitive enhancing and antioxidant functions.  The inhalation of the essential oil either in a steam bath or humidifier is shown to be beneficial in aiding in remembering and recovery.

Research has been done revealing that rosemary’s essential oil and tea has been used to reduce side effects of radiation damage.  In many studies done, it is shown the consumption of rosemary drastically reduces the side effects of radiation sickness.  It is used as a fervent heart health herb because of its circulatory stimulant actions and ability to improve inflammation in the cardio-vascular system.

As with many plants in the mint family,  rosemary is also an ally for colds and flus. It aids in relieving symptoms of congestion in the sinuses by steam, teas or tincture.  According to The Treasury of Botany, a popular dictionary of the vegetable kingdom published in 1866 by John Lindley and Thomas Moore:

‘There is a vulgar belief in Gloucestershire and other countries, that Rosemary will not grow well unless where the mistress is ‘master’; and so touchy are some of the lords of creation upon this point, that we have more than once had reason to suspect them of privately injuring a growing rosemary in order destroy this evidence of their want of authority.’

The leaves can be harvested at any time during the growing season and used fresh, dried or frozen to use during colder months.  Rosemary is easy to grow in warmer climates. It prefers full sun, south facing against a wall to protect from the North wind especially in winter months. Mulching is essential if grown in colder climates outdoors or can be brought indoors easily in a pot and placed in a window in full sun.

Parsley: Petroselinum crispum

Another native to the Mediterranean region, Parsley is a member of the carrot family Apiaceae.  Parsley is a widely used culinary herb, great both fresh and dried.  Many cultures are reported to wear it for various reasons – the Romans in particular wore it as garlands to ward off intoxication during festivals and were given as a wreath during weddings to ward off and protect against evil spirits.  Grown as a biennial herb in northern climates as it takes two years to complete its life cycle.  There are two types of parsley, flat leaf parsley and curly leaf.  The leaves picked in their first year are best.

Parsley offers more nutritional value than most folks are aware of.  It is extremely high in vitamin A and C and it supplies five times more than your needed daily intake of vitamin K, which is instrumental in bone health and blood clotting.  Parsley is extremely rich in antioxidants.  Antioxidants reduce stress in the body associated with oxidation.  To get the most benefits from parsley start integrating it more as a staple than a garnish.  Using it in larger quantities in your salad, pestos and soups.  Most often parsley is more thought of as a digestive aid, however you can also use parsley as an ally for the urinary tract system as parsley aids in urinary tract infections and kidney stones.  Most folks aren’t familiar with the root of parsley, but used as a strong decoction it has a much stronger diuretic action.

Growing parsley is easy directly in pots or in the garden.  Plant in direct sun, in well-drained soil and water regularly.

Ginger: Zingiber officinale

Ginger is historically known as the “great medicine” or “mahaoushadha” among ancient Indians. A native to southeast Asia, ginger has been used for many thousands of years.  Ginger was introduced into the Americas by the Spaniards.  As a tropical perennial it is now widely cultivated all over the world.  It has a subterranean stem, known as a rhizome, that is the edible portion of the plant.  The spicy and sweet flavors of ginger come from the phenolic elements of gingerols, its most abundant constituent.  This pungent herb is very warming and drying. Incredible for aiding in digestion, it works wonders as an anti-inflammatory, antimicrobial, stimulating expectorant  and blood mover.  I often get asked if I could choose only one herb that I could use if I was stranded somewhere, I pretty much always think of ginger.  I use it in the winter months to warm me up, as it improves circulation to my chilly feet.  I drink its fresh squeezed juice to help stimulate my immune system and is a great ally for relieving stomach aches (although be wary of giving the fresh juice to children as it is powerful).

In Chinese medicine the fresh root is called sheng jiang.  In its fresh form its used to promote sweating and as an expectorant for colds and flus.  The dried root is called gan jiang and is used to warm and stimulate the stomach and lungs, a yang tonic and restorative.  Ginger is also used to moderate pain with its anti-inflammatory actions, and is specifically good for cramping associated with digestive issues or menstruation with its anti-spasmodic actions.  For colds and flu ginger aids the body in releasing stuck mucus using a poultice over the chest or by drinking a strong decoction.  Cooking with ginger in soups is a great way to become acquainted with its ability to offer its medicinal benefits by also enjoying its flavor.

It can be grown in a pot in a sunny windowsill, outside during warm/hot months in a pot or interplanted in the garden.  They do very well in the greenhouse.

Sage: Salvia officinalis

There are many different species of sage.  S. officionalis is known as the garden sage – a perennial evergreen shrub also native to the mediteranean region, and also another member of the mint family the Laminacea.  Salvia is the largest genus of this family which includes nearly 900 species.  It is the culinary sage S. officionalis that is familiar to most kitchens.  The word salvia is derived from the Latin word Salveo ‘to save or heal’.  This gives reference to the many healing attributes this plant has.  Traditionally it is associated with longevity and has a reputation similar to rosemary with restoration of failing memory.  In lineage with other plants that are associated with memory, it was a popular herb to plant on top of graves.  Historically it was very popular in trade as well.  While tea was being traded between the British and the Chinese, it is reported that the Chinese valued sage so highly that they would exchange two cases of tea for one case of the English sage.

Sage has a strong and pungent flavor with a slight bitter tang.  This bitter pairs well with fatty food.  The aromatic bitters of sage have traditionally been used in ales.  The leaves can be harvested throughout the growing season and used fresh or dried.  The herbal actions of sage are carminative, antispasmodic, astringent, anti-biotic, reduces blood sugar levels, promotes bile flow, circulatory stimulant, sedative and clears heat.  The leaves can be used in an infusion to create a digestion, liver stimulant, improving digestion.  This sturdy and drought resistant resinous herb grows within a large spectrum of growing zones.

Sage is a very forgiving. It a sunlight lover and prefers well drained soil.  It should be direct sown into pots or the garden.

Using plants in everyday life is essential to health.  The common cooking herbs are rich in benefits and applicable in so many different ways.  Their rich history in the lives of our ancestors has been preserved so much through food and medicine.  Start cultivating your own relationship with the green allies of the plant world into your life by bringing them closer, into your gardens, windows and kitchens.

All information written here is for educational and informational purposes only.  The statements here have not been evaluated by the Food and Drug Administration. Information is not intended to diagnose, cure, treat or prevent any disease.  Readers are advised to do their own research and make decisions in partner with their health care advisor.  If you are pregnant or nursing or have a medical condition please consult your physician.

DIY Activated Carbon

Like everyone else, Living Web Farms is adapting to the changing circumstances of the Covid-19 pandemic.  Expanded farm operations and food donations are now top priority.  We’ve started a new short-form, rough-edit video series for sharing immediately relevant information and a few weeks ago we offered our first of should be many free webcast workshops.  During this workshop I reviewed a number of different low-tech point-of-use water treatment technologies and quickly introduced some exploratory work with production of activated carbon from our wood-waste sourced biochar.  Today, for the blog, I’ll take a closer look at activated carbon and how it’s made and used around the world for removal of chemical contaminants from drinking water.

A screenshot from one our latest webinar-based workshops


Household Water Treatment

In 2015 the World Health Organization estimated that 2.1 billion people do not have safe water at home and of those, 159 million still primarily drink water from untreated surface sources such as streams and lakes.  Surface water is rarely fit to drink unless clarified and treated for the removal of biological and chemical contaminants.

Diarrheal diseases as a result from consuming microbiologically contaminated water are a severe and immediate human health concern.  An often cited WHO publication estimates that 2.2 million people die every year from gastrointestinal infections.  Tragically, young children are especially at risk of life threatening cases of diarrhea and further developmental issues related to malnutrition in non-lethal cases.  The good news is these diseases are largely preventable – and much attention has been paid to providing appropriate microbiological water treatment technologies to those in developing countries, ranging from the no-tech SODIS method, to locally produced biosand and ceramic pot filters, and beyond to the more recently developed higher tech personal use Steripen UV device and Madidrop tablets.  The downside is that, for the most part, these technologies do very little for treating water for chemical contamination.

Chemical contaminants may range from those that are naturally-occurring like arsenic, radon and fluoride, to lead in aging municipal water systems, or to the more complex and insidious herbicides, pharmaceuticals and industrial pollutants.  Interestingly, arsenic can be mitigated with locally-made iron-modified biosand filters and fluoride can be removed by passing water through calcium-rich bone char – However, altogether broad chemical decontamination of point-of-use drinking water is typically done with one of two technologies: removal via reverse osmosis or adsorption with activated carbon.


Biochar and Activated Carbon

If you’ve followed any of our work, then you’ll know we speak often about the physical properties of biochar.  Well-made biochar is resistant to decay, has a well-developed pore structure, and a high internal surface area.  These properties are what makes biochar work so well in building soil fertility – nutrients will ‘stick’ the internal walls of the charred material and diverse microbes can inhabit the open pore spaces.  Well inoculated biochar in the soil helps maintain a thriving soil ecosystem in the midst of external pressures such as tillage, drought or excess fertilizing.  In this way it can be even used as a vehicle for restoring fertility to damaged, lifeless soils.

Visible mesopores in our biochar at 400x magnification

One could think of biochar inoculation as essentially filtering a nutrient rich solution.  For example: If fresh, raw biochar is added to a bucket of tea made from rich worm castings, the nutrients will be drawn in and adhere to the internal walls of the porous char. One could now think of the tea itself as partially filtered.  Extrapolate from here and things get more interesting: biochar can be used in a cascading manner – for example, first as a filter adsorbing excess nutrients from the floor of the chicken coop, then to in the compost to maintain moisture stability and low bulk density, and lastly to its final destination in the soil.  Biochar could be used to filter water contaminants too, although it should be mentioned: careful attention should be paid to what is being filtered and whether or not it is acceptable to accumulate and bury these contaminants.

Before moving on, lets review a few definitions:

  • Biochar is essentially an agricultural or forest waste-based charcoal that is destined for the soil with the intention of building fertility.  This is an important distinction when marketing the material, as biochar is usually processed at higher temperatures than regular charcoal, sieved, and sold in pre-inoculated compost blends.
  • Charcoal that is intended for cooking might be processed at lower temperatures, leaving behind compounds that help it light easier and give its characteristic charcoal flavor.
  • Filter charcoal should be processed at high temperatures, as to remove all possible pore clogging tars and maximize usable surface area.  Typical filter charcoal is a select biomass that has undergone pyrolysis, but has not been Activated.
  • Activated carbon is like filter charcoal, but further processed to increase internal surface area.  Activating charcoal is distinctly different from Incoculating or Charging biochar.

The first documented case of charcoal as a filter substance hails from around 1500 BC when ancient Egyptians used it to absorb odors when dressing wounds.  Around 400 BC, Phoenicians would store potable water in charred barrels on their trading ships to ‘improve taste’. But it wasn’t until the late 18th century that scientists began to understand charcoal’s adsorptive properties.  In 1913 French chemist Michel Bertrand dramatically swallowed a lethal dose of arsenic, followed it with charcoal and survived.  A few decades later, another French scientist would publicly perform a similar demonstration by swallowing strychnine and charcoal in front of the French Academy of Sciences (he was however apparently booed off the stage).  In 1903, inventor and ‘subject of the Emperor of Russia’ Raphael Ostrejko was granted the U.S. patent for a ‘process of obtaining carbon of great decolorizing power’.  What he was describing was carbon with an improved adsorption capacity – produced by applying controlled steam over red hot charcoal – that would eventually be known as activated carbon.


Activated Carbon

Today, activated carbon production is a multi-billion dollar enterprise supplying material to a broad range of industries.  It can be found in numerous consumer products from gas masks to posh cosmetics.  It can be found in hospital emergency rooms, electro-plating facilities, distilleries and water treatment facilities.  Modern activated carbons are produced in a number ways, usually under specific parameters for targeted end-use applications.  All activated carbons are characterized by well developed pore structure and high adsorptive capacities – some may be chemically treated or ionized to target specific pollutants.  Our interest here is in granular activated carbons for water purification. They are generally produced in one of three ways:

  • Physical Activation – Charcoal is produced, sieved to specification,heated to 800-1100C and then steam, carbon dioxide gas, or some other oxidizing agent is carefully applied, creating additional fractures and tiny micropores along its internal mesopores.
  • Chemical Activation – Prior to carbonization, biomass is milled and chemically pretreated – possibly with potassium hydroxide or phosphoric acid, or a salt such as zinc chloride.   Activating agent is chosen based on biomass properties and desired chemical qualities of the end product.  Lower temperatures are required for activation, but chemical activation can be very corrosive to pyrolysis equipment.
  • Physio-Chemical Activation – Charcoal is produced, sieved, and then chemically activated and heated to a high temperature.

SEM photograph of Activated Carbon Source

In water treatment applications, activated carbon is mostly used for the removal of natural and synthetic organic compounds including, but not limited to chlorine and disinfection byproducts, industrial chemical pollutants, and some relatively harmless, naturally occurring compounds that negatively affect odor and taste.  This works mainly through physical adsorption – molecules are drawn in via intermolecular forces and then stuck to the massive internal surface.  One could think of this is a weak magnetic force, or similar to adhesion like dust on tape.  If considering granulated active carbon for a water purification project remember:

  • Contaminants must be in extremely close proximity to the carbon for adsorption to work. Contaminated water should not be allowed to bypass the filter media. For this reason, dense packed filters are better than loose ones.
  • Adsorption improves over time. Slower water flow rates through the filter medium are generally more effective. For this reason, gravity fed systems are generally more effective than pressurized ones.
  • Contaminants will occupy available surface area and build up over time.  Eventually this surface area is no longer available and some contaminants will bypass the filter.
  • Breakthrough is described as the point at which the filter is no longer effective at keeping specific contamination levels under acceptable limits.
  • Well designed carbon filters factor in reasonable breakthrough points for various pollutants and acceptable flow rates.
  • Activated carbon filters can be designed to be more effective at holding some contaminants than others – the breakthrough point of the contaminant with the lowest affinity determines the filter’s ‘expiration date’.

The science of activated carbon is complex, and it’s understood that I shouldn’t expect to be able to make gas-mask or pharmaceutical grade carbon in my backyard over the course of a weekend.  Nonetheless, perhaps out of ignorance, arrogance or genuine curiosity –  or some inspiration by the 19th century French scientists who risked their lives for science – I set out to explore whether it was feasible to make filter-grade activated carbon from our biochar at Living Web Farms.


DIY Activated Carbon

In late winter of this year I set out to explore what it would take to make granular activated carbon (GAC) from our biochar.  My ultimate goal was to have a material suitable for the adsorption of any potential hazardous chemicals in my rainwater collection system.  At my home I have a simple food-grade IBC tote and repurposed barrel collection system that retains water collected from asphalt shingles, aluminum gutters and flexible PVC piping.  400 gallons of storage means I can handle irrigation needs for up to a few weeks, and still have backup domestic water for the times when my aging community well system goes down for maintenance.  Incoming rainwater is almost always cleaner than surface water – although one must consider the roof itself is a surface of its own.  I would need a system that allows for settling of particulate matter, simple filtration, microbial deactivation (I’ll be using chlorine for residual protection) and protection against potential organic compounds and chlorine byproducts.  Now I use the popular Berkey brand carbon block filter system – in the spirit of self-reliance, for future experimentation I’ll be using a refillable canister filter and allowing for the longest possible filter contact time.

My simple rainwater collection system

For our experiments in activated carbon production I took inspiration from the immensely popular Cody’s Lab YouTube channel.  Cody does a great job in his video explaining activated carbon, where he then goes on to produce a small amount of steam-activated material in an electric induction oven and follows it up with an iodine test to compare its adsorption capacity to store bought material.  My plan was to perform a similar experiment, using our hardwood biochar as a feedstock, screened and heated with LP in the standalone refractory chamber our team built when developing our atomizing pyrolysis oil burners.  At the same time I set out to compare the adsorption capacities of several ‘DIY’ chemically activated chars, this time, following the recipes provided by several other popular youtube and survivalist-themed blogs.  Unactivated char produced in my TLUD cookstove was also compared.  Adsorption capacities of the final products were to be compared with two simple tests: (1) via visual indication of methylene blue adsorption and (2) following the R-134a adsorption procedure as described in chapter 8 of the Biochar Revolution.

Samples were prepared:

  • Enough retort-made biochar for several tests was screened to <1/8” and >1/16”, rinsed and dried at 350F for 2 hours.
  • TLUD char was similarly screened, washed and dried.
  • Canning jars were filled with the uniformly dried, granulated material and sealed until activated.

I proceeded to test several DIY chemical activation methods, following guidelines set out by popular DIY and survivalist-themed blogs:

  • A 4 oz. jar of prepared char was covered in 3 oz. of lemon juice and covered overnight.
  • 30mL of calcium chloride was dissolved in 100mL of distilled water.  This mix was poured into a 4 oz. jar of prepared char and stirred to paste consistency.
  • A potassium hydroxide sample was prepared similarly.
  • A wood-ash sourced potassium carbonate sample was prepared similarly.
  • All jars were covered and allowed to sit for 24 hours.  After which they were well rinsed over a stainless steel screen and oven dried for 2 hours at 250F.

Making a paste while attempting DIY activation with calcium chloride

In the meantime, a vessel was built for applying steam to heated char.  Again, taking cues from Cody’s lab, I knew it was important to distribute steam evenly, for a short time across a column of heated granulated material.  The vessel would need to accommodate a volume of sacrificial char in order to prevent any excess oxidation during heating.  Two samples were prepared, a steam activated sample and a heated, non-steam activated sample.  Both samples were slowly brought up to 1800F and held there for 1 hour.  Distilled water was simultaneously heated in a cast iron teapot.  Steam was generated and applied in 2 minute increments for a total of 10 minutes over 20 minutes time.  Samples were allowed to cool and stored in canning jars until testing.

Experimental DIY steam activation. Not as dangerous as it looks!

Activation vessel, showing steam input and sacrificial char.

All samples were stored in canning jars and labeled as follows:

    1. Control – Retort biochar, carbonized at 850F for at least one hour.
    2. TLUD – Char generated in a gasifying cookstoves.
    3. High Heat – Retort biochar, heated to 1800F for one hour.
    4. Steam – Retort Biochar, heated to 1800F and steam applied for a total of 10 minutes.
    5. Commercial – A store bought granulated aquarium filter carbon.
    6. KOH
    7. CaCl2AKA “Pickle Crisp”
    8. K2CO3
    9. Lemon

30 mg samples of each carbon were measured into 35 mL test tubes and covered with 30mL of 1% methylene blue solution.  Samples were gently stirred, covered and allowed to sit for 24 hours.

1% solution after 24 hours.

After 24 hours there was some visible change, but I wanted a more nuanced look.  30 mg samples were similarly prepared with a .25% methylene blue solution.  By this point I had run out of commercial activated carbon.

.25% solution after 24 hours

.25% solution after one week.

In the meantime, samples were compared with the R134a test as outlined in Chapter 8 of the Biochar Revolution.  In this process, a known weight of char is loaded into a small vessel and swept with a heavy refrigerant gas. The adsorption capacity is estimated by the weight gain of the sample.  The end point of the adsorption reaction is determined by a temperature change – the char sample heats up during adsorption, followed by a temperature drop when it reaches capacity.  I had some trouble determining this point – ultimately it took three cans of refrigerant until I was confident it was done.  Nonetheless I proceeded to compare the before-and-after weights of my remaining samples:

R134a adsorption test

Documenting percent weight change after adsorption of R134a.



The steam applied char performed well in the methylene blue test.  There was little difference between control and high heat chars.  All chemical-activated samples performed poorly – in all cases worse than the control char itself.  Simply applying a strong base, acid or salt to the char and rinsing does not work to create activated carbon – in time, I’ll attempt a proper physio-chemical activation by heating these chemically activated samples up to 1800F and compare again.  For now, it’s safe to say that the chemical activation methods repeated on many YouTube and blog posts are not helpful in improving the adsorption capacity of proper charcoal.  It is possible they help to some degree in improving low heat, tar-clogged chars, but it is doubtful the result is anywhere near what may be considered activated carbon.

The TLUD char was the star of the show – It compares surprisingly well, and given enough time, with the naked eye it appears to perform nearly as well as steam or even better than commercial activated carbons.  This confirms the rule that higher filter contact times make for more effective filtration.  These results are especially exciting given that TLUD char production requires no additional energy input and is much less demanding of my labor.  I look forward to testing again with TLUD production methods combined with chemically activated biomass – I’ll start by soaking hardwood chips in a solution of wood-ash sourced ‘lye-water’.

Since performing these experiments I’ve come across the work of Dr. Joshua Kearns and the work of Aqueous Solutions.  This is exciting stuff – their team is researching and developing extremely low-cost, locally-constructed, multi-barrier water treatment systems that include high-temperature biochars for removing chemical contaminants.  Kearns’ peer-reviewed work has been shared with the International Biochar Association and CAWST – Open source plans are available here.  What’s most exciting is that this work confirms high temperature biochars – those made with improved (still simple, still locally made) TLUD style methods – perform nearly as well as the ‘gold-standard’ activated carbons for adsorption of a variety of common surface water pollutants.  Essentially, according to his research, there are no major differences in the feedstocks tested, but rather the difference is in production method – gasification chars, made with high temperature methods perform much better than lower temperature kiln-produced charcoal for control of organic chemical pollutants.  Activated carbons ultimately still perform better for adsorption, but when compared to char that can be locally made with agricultural wastes on low tech production equipment, the cost/benefit analysis doesn’t always check out.

Want updates? Questions answered? Comments and criticisms? Send me an email.

Home-Scale Biogas Production

My enlightenment on the subject of biogas began when I stumbled upon an article in a dog-eared copy of The Mother Earth News entitled “Chicken Manure Can Power Your Car.”  Buried among debatable bootstrap business stories and homespun garden-prep tutorials, the write-up recounted how a one-legged British maintenance man named Harold Bate converted a 1953 Hillman sedan to run on decomposing poultry waste to circumvent what he saw as an unreasonably high tax on gasoline.

At the time I didn’t realize that not too far into the future I’d be building and operating a similar methane digester at the very same publication that ran the story years before. I’d been hired by the magazine and almost immediately thrust into the development of a 624-acre research farm in the mountains of Western North Carolina, where biodynamic gardening, permaculture, alternative energy, and natural building were the rule, not the exception. The experience left me with a newfound appreciation for the convenience of petroleum fuels–but it also opened a vast world of unexplored alternatives.

old TMEN methane digesters

My earliest foray into biogas, setting up a Servel gas refrigerator to run off the biogas generating tanks in foreground

There’s probably no better time than the start of the Spring season to talk about methane digestion—now referred to as “biogas” to more accurately describe its place in the hierarchy of renewable energy. Spring is nature’s time for rebirth and renewal, and the decomposition process of turning waste into a new form, a burnable fuel, is not so far removed.

The Living Web Farm project began in 2018 when we agreed to set up and test the Home Biogas system, a small home and farm scale anaerobic digester manufactured by a startup collaborative in Beit Yanai, Israel.  Unlike more permanent systems, this one uses a reinforced flexible bag as a digestion tank and a second sealed chamber as a gas storage bag. A molded plastic inlet feed sink is attached at one end and liquid fertilizer outlet at the other, with a gas filter and management setup fastened to the gas storage chamber.

setup before filling

The 300 gallon system is compact and occupies a 4 x 8 footprint

This approach makes it fairly easy to set up and operate a gas-generating system as long as you have raw materials available to feed it. This would include animal manures, food wastes, and garden culls such as vegetables, fruits, and even meat and fats. So let’s take a look at how it works.

What is Anaerobic Digestion?

In the short version, it’s a natural process in which organic materials decompose in the absence of atmospheric oxygen. Unlike aerobic digestion, familiar to most of us as simple composting, the anaerobic process involves specialized microorganisms known as methanogens whose metabolism generates methane in low-oxygen conditions. Because they do not have access to surrounding air, their limited oxygen requirements are derived from the organic material itself.

The transition from organic material to gas occurs in four stages. The first is hydrolysis, in which a watered slurry breaks down chemical bonds in complex matter such as carbohydrates and proteins into simple molecules of sugar and amino acids. The second stage is acidogenesis, by which those molecules are converted into ethanol and fatty acids, creating carbon dioxide and hydrogen sulfide coproducts. In the third phase, the ethanol and fatty acids transition to hydrogen and acetic acid in a process called acetogenesis. Finally, in the fourth stage the methanogenic organisms prevail to convert remaining hydrogen and acetic acids into methane and additional carbon dioxide. The composition of biogas is typically 55 to 65% methane and 35 to 45% CO2, with traces of nitrogen, hydrogen, water vapor, and hydrogen sulfide. The last two components are stripped out with a condensation trap and ferrous filter to improve the quality of the gas.

Fortunately for us, this complex series of events occurs without our intervention, save for providing a hospitable environment and a regular ration of feedstock material. Hosting the accommodations essentially means maintaining a consistent temperature above 75 degrees F and monitoring the slurry chamber’s pH levels. A surprising variety of kitchen and garden wastes, and animal manures, can successfully contribute to the generation of methane gas, but too much of certain things will crash the pH balance, dropping the levels into acidic territory and requiring a minor course of stabilization.

Even if the temperature falls below the threshold or pH levels stray from the ideal neutral zone, it does not kill the gas-producing organisms; they will simply go dormant until corrections are made and they can continue on their natural path. Extreme cases of pH imbalance will render populations inactive, in which case they can be easily jump-started with an infusion of fresh manure.

Why Bother?

Before I answer that, I want to answer this: Methane is a greenhouse gas. Why would we want to make more of it? The short answer is that livestock manures (among other things) generate methane whether we intervene or not. Here we are simply making and capturing it in a controlled fashion. Allowing it to degrade in the environment causes direct atmospheric emissions, the second greatest source of GHGE in intensive dairy operations. Coincidentally, volatized ammonia from concentrated livestock manures becomes residual in water and land ecosystems and can subsequently convert to nitrous oxide emissions as well.

But back to the question: we do it because energy provided by biogas can replace its share of fossil fuel, which happens to be the prime contributor to greenhouse gas emissions. Biogas energy is considered carbon neutral, since carbon emitted when burning it comes from the carbon fixed by plants in their biological cycle.

Biogas energy can be a supplementary source of income on a larger scale, but for small-potatoes producers it could reduce or eliminate the need for a propane delivery or a natural gas hookup. It can be a source of cooking, heating, or lighting fuel in any location, on or off-grid, and its residual digested matter can be further composted to provide nutrients to garden soils.

Granted, biogas does not have the energy content of natural gas. Due to a lower methane component, it contains about 25% less energy in Btu’s per unit, but it is has the advantage of being renewable and does not have to be extracted from the ground. Each cubic foot of biogas contains about 600 Btu’s of energy, so the standard measure of one cubic meter (35 cu. ft.) provides 21,000 Btu’s or the equivalent of 6 kW hours of heat energy–enough to keep a cookstove burner going for 4 to 7 hours (depending on its size) or a 100-watt light bulb on for 60 hours.

boiling water in pan

A single cookstove burner can operate for hours on the digester’s daily output

Post-Digestion Particulars

The amount of waste going into the digester is almost equal to the amount coming out. But the quality of that residue is improved with far less odor and a higher quality fertilizer because the nitrogen in the effluent is more readily absorbed by plants than the nitrogen contained in raw manure. Its nutrient value remains nearly as complete. Liquid effluent can be drained off and used as fertilizer; the solid component is removed periodically and is normally composted.

Through the anaerobic digestion process, most disease vectors are destroyed and external odors are eliminated, resulting in an impressive level of insect control. In fact, the only odors present in a healthy system exhibit as a slightly musty scent and are contained in the digestion tank itself, which is sealed from the outside environment.

The Need to Feed

As I mentioned earlier, hosting a biogas digester requires maintenance heat, pH balance, and a third condition familiar to home composters–a favorable Carbon to Nitrogen ratio.

Although reaction temperatures as low as 75 degrees F will keep the system functioning, ideal mesophilic conditions occur closer to 95 degrees. At this level, volume production and efficiency are optimized, and retention time can be as low as 15 days. The digester at Living Web is currently housed in a small greenhouse enclosure where it sees direct solar gain throughout the year. In the winter months, endwall and subfloor extruded polystyrene insulation works to retain some of the heat, but a 300-watt internal tank heater carries things through the night and the coldest days. (The digestion process itself generates some thermal energy.) Over the next month, we will be relocating the system to a large greenhouse at our Grandview location, where it will be far easier to feed and maintain, and where there is room for additional gas storage in a separate auxiliary container.

LWF biogas enclosure

A simple poly-skinned enclosure makes a good all-season environment with addition of extruded polystyrene insulation

pH levels are ideal in a range between 6.5 and 7.5. Digestion problems usually present as a drop in pH, which “sours” the system. The condition is easily corrected with a dose of sodium bicarbonate (baking soda) or sodium carbonate (washing soda). Infrequent alkaline conditions are remedied with an application of common citric or lactic acid.

The C/N ratio directly affects gas potential and undesirable ammonia production. Carbon to Nitrogen ratios between 25:1 and 30:1 have proven to be ideal. Keeping the C/N ratio in check is a matter of calculating, by weight, the values of individual inputs to the substrate used as digester feed, which are available online at sources such as this homesteading site.  Most livestock manures are already in the desirable range (poultry being one exception), so you’ll mostly be paying attention to supplemental garden and kitchen wastes.

The suitability of a substrate or feedstock for digestion depends not only on C/N ratios and pH levels, but also on the amount of total and volatile solids in the material. Livestock manures are usually in a slurry form with a limited dry matter content, but our horse manure required mixing with water to achieve a slurry. Too much dilution reduces the volume of manure input and too much dry matter can cause operating difficulties.

slurry mix

Solid manures are mixed with water to make a slurry for starter activation

To activate the system a starter manure slurry of 8 to 10% total tank volume is introduced into the digestion chamber, where it takes 10 to 21 days to digest and start producing gas. Suitable manures include horse, cow, sheep, swine, rabbit, goat, poultry (with caveats) and others, but manure is not necessary to keep the system going once gas is being produced. Vegetables, fruits, kitchen and dairy products, fats, meat scraps, seeds, and eggshells are all fair game feedstocks at this point, though manures can continue as part of the matrix if it’s available.

This, in fact, was a lesson I learned with the original methane digester years ago. Committing to one substrate limits the collective value of having a digester on the homestead that, in fact, is equipped to consume almost anything. Though it’s convenient to have a consistent feed regimen, you are limiting the digester’s potential if you don’t consider all inputs, including rotten and molded foods. Food waste has a high energy potential because it has not been digested by the stomach of an animal—particularly foods high in calories, starch, and sugars.

As far as volume, our 300-gallon system can accept up to 2 gallons of food and garden waste a day, or 4 gallons of manure slurry, including dog and cat wastes. Any input should be free of soil, straw, and non-digestable materials such as stones and twigs.

Other acceptable substrate materials, to be considered on a limited basis, include citrus (it has anti-bacterial oils), oil and cooking grease, poultry manure (high ammonia levels), fish, and spinach. Materials to avoid would be cardboard, tissue paper, fur and feathers, coffee grounds, sawdust and wood chips.

What to Expect from Biogas Digestion

The 300-gallon capacity turnkey system on our farm is one of many existing designs, and though it’s convenient it is also relatively small because it was intended for use on a home scale. The gas storage bag has a 24 sq. ft. capacity which is the equivalent of about 4.5 kWh of energy, or just about 15,000 Btu.

cross section Home Biogas

An illustrated cross section of the biogas unit. Weighted ballast at top provides gas pressure

Additional storage can be added, but the gas is difficult to compress and the technology impractical at this scale, so reinforced bladders are the storage of choice. With a moderate daily feeding of 2 lbs. of food scraps you can expect about 20 cu. ft. of gas daily under ideal conditions. Larger managed permanent systems perform even better, with some producing 1 cu. ft. of gas per day for every cubic foot of digester capacity.

gas outlet

Gas is extracted through the small black piping and can be delivered up to 50 feet for use

In working with a flammable gas, safety of the system is always important. Though methane content of the gas will fluctuate slightly with digester conditions, biogas is essentially odorless, colorless, and lighter than air so it is difficult to detect. It is also an asphyxiant, like natural gas and propane. Its flame often burns with complete clarity so it may not be visible.

Maintenance is an occasional thing, but nonetheless important. Any leaks in the digester tank or liquid fittings need to be addressed promptly for sanitary reasons as well as performance. Gas leaks are critically essential to avoid, but since the system works at a very low pressure of 4” water column—about 0.15 psi—they are not particularly forceful and easy to detect using a liquid soap-water mix at the joints. We have never experienced a leak.

manometer pressure

The biogas system works a a low pressure of less than 4″ water column or 0.15 psi

At some point the solids collect in the digester tank to the level where they must be removed. In this case, the liquid is siphoned or pumped out and the solids extracted through the port built into the base of the tank.  The chamber is small and manageable enough that this is simply a chore and not a battle.

Granted, most of us probably will not be going to the lengths that Mr. Bate did to get his vehicle running on manure gas, but a regular supply of site-made biogas fuel isn’t beyond the capacity of anyone with a small farm or homestead. And yes, outside of cooking, lighting, and heating water, it is possible to power a stationary generator that would normally run on gasoline or LP with biogas fuel as long as it is cleaned and filtered properly, once fuel system modifications are made. The issue is not technical but more of a supply question, since one gallon of gasoline is the equivalent of 200 cubic feet of biogas.