wildcrafting

Growing & Making Fermented Indigo Dye

fermentation, wildcrafting

All of us are born dyer right? We’re born with the ability to fumble our mug of tea onto our shirt in an uncontrolled moment. Any of us can make browns, as lots of plant materials oxidize into other shades like yellow too. However blue is a much more difficult one and rarer in nature to achieve.

The substance in plants that makes blue exists in many botanically unrelated plants. Examples from across the globe include: “True Indigo” – India (Legume), Anil- subtropics (Legume), Indigofera bracteolata (maybe Dugwa lala)- West Africa (Legume) , Woad- Middle East/ Britain (Brassica), and Japanese Indigo- (polygonaceae). Japanese Indigo is what the following information will specifically pertain to. Even as these plants grow geographically and culturally separated, the process for obtaining pigment is generally universal despite the techniques being discovered independently.

Growing

Japanese Indigo is sensitive to frost. The damage to the leaves from frost and insects are interesting ways of speculating how the pigment was discovered, as the damaged leaves show a curious blue hue. Start seeds indoors around the same time as tomatoes or direct sow after the frost date. They can be a little slow to germinate but will grow quickly thereafter.

Japanese Indigo requires no special growing conditions, good fertility gives more leafy growth, which is what we are after as the pigment is in the leaves. A rich soil and ample water will increase your yield.

Harvest the indigo before flowering by cutting the plant down to a couple inches above ground. Japanese Indigo will easily regrow after being cut and it is possible to get multiple cuts in a season depending on your situation. Do consider not cutting the best performing plants in order to let them go to seed. Harvest these just before the frost so they have a chance to mature. Also make sure to get a final harvest in right before the frost arrives.

Pigment Extraction

There are many different ways to process the harvested indigo from drying to composting, to using right away for fresh dyeing. The following process explains how to extract the pigment from the fresh leaves that can then be stored for later use. It is the preferred method for our farm as the first cutting usually comes in late July when time is more scarce and the harvest is the greatest.

Leaf cells contain indican and an enzyme that are kept separate until the cells are ruptured. Combined they make indoxyl. Indoxyl when exposed to oxygen becomes indigotin- blue. So first the cells must be destroyed to begin extraction of the pigment.

If you happen to have a protein based fiber you can pick the fresh leaves off the stems into a bowl, sprinkle a little salt, and massage the leaves into your cloth which will rupture the plant cells in a process that feels very much like making sauerkraut. The result is a teal color.

Fermentation Extraction

Immediately after harvest, plunge the whole cut plants into water weighted down. We use 44 gallon Brute garbage cans. Warm temps are ideal like 70° with a lid. Placing the container outside in the summer under some shade is great.

Let it ferment for 3-4 days or until the pigment is noticeably spent from the leaves. You should be able to notice the water having a greenish-blue hue. Discard the plant materials into the compost. Fermenting too long can decrease the amount of pigment.

Bring the remaining liquid to a pH between 11-12 with lye, hardwood ash, or Cal/lime. A pH measuring tool can be used or you can incrementally add your alkalizing agent, stirring vigorously, until the water reaches a hue of blue you want. Raising the pH will darken the blue color.

Stir and splash vigorously for as long as you can to introduce oxygen. Then let the mixture settle a couple hours or overnight. The top liquid should be clear of any blue with the pigment settled on the bottom. If there is still blue suspended in the water then go back to vigorous agitation and try again. If it still doesn’t separate try dropping a couple bags of ice in- this has worked for me in the past. When the pigment has precipitated, the top liquid, which will be yellow-hued should be poured off until all that remains is a blue sludge. The settled pigment goo can be dried down into a pigment powder or left as a paste. In this state it is usable to make paint or ink but needs an additional process to be able to adhere to fibers, specifically plant fibers.

The Dyeing Vat

The indigotin produced through the extraction process is insoluble in water. However when oxygen is removed and the pH elevated (+11) it converts into leucoindigo/ white indigo (it’s technically colorless now) and dissolves in liquid and can now adhere to cellulose fibers like cotton and linen. Fibers introduced to leucoindigo collect the pigment, then when removed from the liquid and reintroduced to oxygen returns the leucoindigo back to indigotin thus dyeing blue.

Two ways to remove oxygen is through an active fermentation or by chemicals such as Iron (II) Sulfate Heptahydrate.

In a bucket of clean water add lye/ hardwood ash/ or cal to reach a pH of between 11-12, then add processed indigo pigment.

For a chemical reduction add Iron (II) Sulfate Heptahydrate, something like 60g per 5 gallons. It can be helpful to dissolve it in hot water first. Stir everything then let it rest before using the vat.

For a fermentation reduction add a sugar, preferably from a fruit source, but it can also be as unassuming as bran. Add a starter like unpasteurized vinegar/ wine/ sourdough starter. Leave the vat in a warm place to ferment until it is vigorously bubbling. At it’s peak activity the vat is ready for dyeing. This vat can be reactivated much like keeping sourdough starter, though all of the vats can be used indefinitely as long as the pigment gets replenished, the pH stays within range, and the reduction is reinstituted.

Dyeing

Presoak clean cellulose fabric in clean water and wring out. Dip carefully to not disturb the vat and introduce any oxygen. Leave the fabric in the vat for 30-60 seconds and carefully pull it out, gently wrigging out the fabric, then rinse and squeeze out in cold water.

Repeat the dipping steps to get the blue color you want. The more dips will create darker colors as opposed to longer dips. Keep in mind how the blue color will lighten as when it dries.

When you’re finished, rinse your fabric in cold water with a splash of vinegar to reset pH.

There are so many different techniques for dyeing with resists, folds, and ties that will be a final layer of excitement to your home grown and processed indigo.

How to Make Homemade Clay… and ferment it!

mold, wildcrafting

Making homemade clay is another great chance to interact with the natural world around us and help us get to know our surroundings even better. It doesn’t require any special equipment and even a general knowledge can produce a good quality clay for endless hours of fun. I love clay as an off-season activity, especially as the forest floor lies barren any hike can become a scouting mission. Clay also comes with the added benefit of adding another potentially fermented skill to your fermentation-arsenal, through it’s bacterial breakdown during aging.

Finding Clay

Clay is possible to find in many regions. The best places to look are areas where there is running water such as a stream, creek, or a river. Running water washes away the less dense soil particles revealing the strong water-holding layer of clay. It can be a lot of different colors such as grey, white, orange, and red, and has a slick, plastic-y appearance when wet. When it is bone dry, it’s noticeable by its cracking.

In addition to running water, construction cuttings into the earth, such as roadwork and building foundations are also great places to hunt for clay.

When you find an area that may contain usable amounts of clay, test it first by taking a handful and kneading it in your hand. Add water if necessary and test its malleability. The properties of clay will vary from location to location. If you can roll it into a coil and bend it into a ring then you have found yourself some good quality clay to work with. My favorite places with the best success have been hillsides with deep creeks cutting through them. Often the clay is easily visible just by looking at the stratification of the soil layers.

Harvesting

In all cases when harvesting from nature its essential to be mindful and respectful to the place were taking from. Take only what you need and be thoughtful to not influence unnecessary destruction. The great thing about making your own clay is how easily it will return to back to the earth.

Fill up your container, whether a bag or bucket. Any “debris” such as sticks and rocks and such we will filter out later, no worries if there’s stuff in it. It may be dry or wet, either way is fine. A stick, rock, trowel, or your own paws should be sufficient to dig with.

Processing

Unload your collected clay into a large container, at least twice the size of your amount of clay. Add enough water to the container to achieve a loose slurry, it should look like chocolate milk, maybe with sticks and leaves in it. Stir it up well. If there are chunks holding together, break them up with your hands. Let rest overnight to give the water a chance to really soak in.

When you return to the slurry, check to make sure all the chunks are broken up and all the clay is dissolved into the water. Give it another good stir. When the clay is fully dissolved into the slurry you are ready for straining.

Prepare your straining apparatus. We are not necessarily looking for a tight sieve, some netting will do fine. While we want to remove any stones and forest debris, we still want some variable sized particles, just not anything noticeably big. Sand and larger (relative to clay) particles known as grog actually provide strength to clay, and helps prevent cracking and warping by influencing a more even dry. I have strained through a kitchen sieve, a dehydrator tray, and a whole variety of fabric, plastic, and metal mesh. Give the clay a good stir to loosen up anything sunk to the bottom then pour over the sieve.

Finishing

At this point you should have some clean clay slurry and all we have left to do is dry off the water. Depending on the amount of excess water you may be able to skim some off the top as the clay settles down. Check for clear water on the surface.

You can blow a fan indoors or place the clay outside in the sun. In either case be mindful of surface drying and stir the clay periodically as needed to keep it working uniformly. Keep an eye on it and over the course of a few days you should see it thickening up. Watch it and play with it until you have reached a good workable consistency. Consider erring on the side of “wetter” as it’s easier to remove moisture than to add it back, but both are still possible.

Aging & Fermentation

The longer that clay is aged for the more potential it has to be broken down into finer particles that can be made into finer ceramics. Aging clay in an environment where it won’t lose moisture- such as in a plastic bag or a lidded bucket, allows the slow penetration of water in the clay particles that makes them smaller in size, and thus increases the clay’s plasticity.

During the aging of clay it can also sour. This is when bacteria present in the clay continue to decompose it. Through the process, amino acids are released which bond particles to further increase its plasticity. As the bacteria works the acidity also increases which brings particles closer together and forms a colloidal gel, which creates a very strong lattice giving the clay favorable strength. A rotten or moldy clay is prized for these reasons inspiring people to add all sorts of things like beer, vinegar, and milk to their clays. A rott-y clay can be used as a “starter” to inoculate new batches. I inoculated my clay with bacillus subtilus, a bacteria used to make the fermented food natto, but is also occurs naturally in the soil. I mixed it into the slurry during the “drying” phase, right after “sieving”, to experiment with this breaking down. And how’d it go? Who knows, but it’s about a year later and regardless the clay feels great!

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