An additional beauty of dark Indigo is that when ironed or pounded, the blue cloth takes on a beautiful coppery sheen – the same sheen that is seen on the well reduced Indigo vat, when it is ready for dyeing. When ready to dye again, warm it up, renew it with the ingredients, and proceed as before. The fibre is worked in the solution, or “vat.” When brought out to the air, it is a bright green. However, many of these cultures now use synthetic Indigo, manufactured from coal tar or petroleum. Enter the fibre (yarn/fabric) into the vat very carefully, to avoid adding any air to the vat. The indigo vat is very alkaline. It must be ground to be used for dyeing. It should feel pleasantly warm to the hand. The liquid, lifted carefully in a glass jar, will appear green. Next day I soak in two successive waters for about an hour each time, rinse again, wring and dry. Then let sit a few days to re-ferment. Over time a deposit of sludge will develop at the bottom of the vat. The solution is then beaten to oxidize and precipitate the Indigo. Dyeing is begun, with the darkest colour dyed first, then medium, then lights. Any air remaining in the fibre will oxidize Indigo in the vat, and this must be avoided. Indigo blue has still the association of “The Working Class”. It is an excellent rotational crop for increasing soil fertility. Indigofera is a legume. Now the fibre must be “worked” in the vat, under the surface. An oxidized (blue coloured) vat won’t dye well. WARMTH: It is necessary to keep the vat warm, but not hot, around 100 – 110° Fahrenheit. Always work under the surface of the vat. Indigo in some form is used in all traditional cultures, for it is the only clear and fast natural blue. In southern Mexico, where some of the current Indigo of commerce originates, it is naturalized and grows in fallow fields, so no effort is spent cultivating it. The amounts are weight ounces, not volume ounces. Indigo dyeing was one of the first speciality professions. It takes time to do the dyeing. TIME is very important. To keep it warm, a light bulb in a reflector can be put under the vat, with a blanket over it to keep in the heat. 2 oz. It takes time for the vat to ferment and it does no good to try to rush the process. With “renewals” the time needed is a bit less, four or five days. The Indigo plants are harvested and brought to a central location. Slowly the air changes it to the beautiful deep and rich blue of Indigo. For more detailed instruction and recipes for colors, please purchase the book Brilliant Colours with Natural Dyes. In this way a vat can be kept going for many years. Be sure to remove the screen after the day’s dyeing, so you can stir the vat before closing it. We use the distinction as “Blue Collar Workers” and “Blue Jeans”. This recipe is the one most commonly used for home dyeing. After you have worked it several minutes, carefully and slowly raise it out of the vat, squeezing the excess Indigo solution back into the vat. Between dyeings the vat must rest overnight or an extra day. You may want to gently lower a screen into the vat before dyeing, to keep your fibre from pickinging itup during the dye process. It is not good to leave a vat unused for too long, as it is a living process and may then get cranky about starting up again. In a warm climate no additional heat is needed, but be sure the vat is out of direct sun so it does not overheat. You don’t want to scare people with blue hands; also the strongly alkaline vat may irritate your skin. If you leave more than 2″ of air at the top of the vat, it will not reduce properly. It contains no harsh chemicals nor toxic metals. The vat is let to ferment for several days, and is ready to dye when it shows the proper signs. Air between each dip. The dye process is unique, and the facilities require a stable set-up. It is begun with a certain amount of Indigo, and all other ingredients as given, in proportion. Rinse well. Also it is important to exhaust the vat before leaving it, or it may over-ferment and ruin any Indigo remaining in it. Vats made of great clay pots set in the ground are commonly used in warmer climates. The first time, it takes about a week for the vat to ferment and be ready to dye. The vat is “renewed” with more Indigo and the other ingredients in proportion, whenever the dye value weakens. These complexities give Natural Indigo nuances and depths that cannot be achieved with the synthetic substitute. Traditional fermentation methods are used. The size of the pot is determined by the amount of fobre you need to dye at one time. If more heat is needed, pits for burning charcoal are placed between clusters of the vats. Combine these ingredients in about a three gallon pot of warm water. Any time you break the surface you introduce air into the vat and this you do not want to do. Always wear rubber gloves. It withstands well the many washings that work clothes require. The process “reduces” the Indigo, changing it from blue to yellow. Now is the exciting time to begin Indigo dyeing! Keep the vat covered. It is dyed through a living fermentation process that does not require any mordant. Repeat the dips up to five times for dark Indigo Blue. Indigo dyeing is practiced today in Japan, Southern China, Tibet, India, Indonesia, Indo China, Africa, especially Nigeria, Southern Mexico and Guatemala, and it has recently been reintroduced to Turkey. The level of liquid in the pot should just allow room for the yarn dyeing, without spilling. It is important to rinse out all the alkalinity. Natural Indigo contains several related dye chemicals that give different shades of blue. This is because, during dyeing a certain amount of the Indigo is oxidized in the vat. The plant looks similar to alfalfa, but is usually larger. If one wishes to rest from dyeing for several weeks, simply turn off the heat source, and keep the vat cool for that period. ground indigo, 1/2 lb ground madder, 1/2 lb ground bran and 3 lbs washing soda in about a 10 gallon plastic tub. The less air between surface and lid the better. Excess water is poured off and the sludge is dried. The idea is to integrate the undissolved Indigo, madder and bran that settles to the bottom, back into solution. I have had my current vat over fifteen years. However, I advise starting small, till you are comfortable with the process. The vat itself lasts a long time. An additional beauty of dark Indigo Blue, is that when ironed or pounded, cloth so dyed takes a coppery sheen – the same sheen we see on the top of the well-reduced Indigo vat. It will start to turn blue in the air immediately. A larger vat can be made, for example with: 1 lb. A zip-loc baggie cinched over the grinding plates catches all the powder and keeps blue dust from getting everywhere. A three gallon pot is good for yarn skeins of 4 to 6 oz., while a 10 gallon or larger tub will be needed for yards of fabric. It can be used to dye any natural fibre. So stir gently. Indigo dyeing by this natural fermentation method is a slow-steady process. Allowing it to rest lets it re-reduce that Indigo. This separates the dyestuff from the plant. Indigo Natural Fermentation Vat. When the vat is “exhausted”, and will only dye light shades, it is time to renew it. These clothes were originally dyed with indigo. Below is what the indigo vat should look like at the end, when it is ready to use. The fibre is … Squeeze solution through yarn for best penetration. The fibre should be a bright clear green. In most cultures, Indigo dyeing is or was a specialty. It is good meditation. Yet it is easy to keep a home pot going, and most colonial homesteads had one. It is dyed through a living fermentation process that does not require any mordant. I use a domed lid, turned upside down. (See illustration, next page.) This sludge, packed into balls or patties and fully dried, is the Indigo dye of commerce. And to do this without incorporating air into the vat. A test piece of fibre or paper will emerge green and turn blue in the air. Just to be on the safe side, I always double rinse my indigo dyed textiles. Wet your fibre out very well in warm water. Soak and do a final rinse in the morning. It develops a coppery film on the top of the vat. A Corona Corn mill is what I use. In this state, it dissolves in an alkaline solution. For lighter shades, fewer dips are needed. Though the process of turning green leaves into brilliant blue dye through fermentation has been practiced for thousands of years, it still feels magical.Most natural dye colors are derived from bark, berries, or leaves that can be boiled down and dyed with—but the process of making blue dye … In this state, it dissolves in an alkaline solution. For greens, dye you fibre Indigo first, then rinse well and overdye with alum mordant and your chosen yellow dye. Meat grinders also work. In most traditional cultures, the colour(s) of ones clothing indicates ones status or class. For purples, dye the Indigo first, rinse well, then mordant and dye over with any red dye.