infatuated with indigo
Sept. 2106 addendum: The post below describes my first experiment dyeing with my fresh indigo plants, but I used a synthetic reduction agent called Thiourea dioxide. Preferring not to use any chemicals, I am presently experimenting with a few different natural vats, based on information from Michel Garcia, via Maiwa. Recipes here.
This spring I attended a natural dyes workshop taught by Rebecca Burgess. The plant materials in the dye baths prepared by Rebecca created a beautiful array of colors on samples of wool yarn and silk scarves. Plants used included Japanese indigo (blue), toyon (orange), black walnut (brown), fennel (soft green), french broom (soft green), and coffee berry leaves (yellow). The class inspired me to learn more about natural dyes, so I bought some indigo seeds (Polygonum tinctorium) from Rebecca, as well as some from Britt Browne, and planted them in my garden.
By late July, the plants were ready to trim for my first batch of dye! I studied the notes that Rebecca sent with the packet of seeds, plus I did some internet research. Good information was gleaned from several websites:
On the morning of July 20th, I trimmed the plants, removed the leaves from the stems, and placed the leaves in a one-gallon jar with warm water. Based on what I had read, I decided to let the jar sit on top of the refrigerator (where it’s warm) for 24 hours.
Two days later I had not yet made the dye bath, and I trimmed more plants and filled another jar with leaves. One thing led to another, and before I knew it a week had passed! As you can imagine, the brew in those jars smelled extremely bad, but they produced wonderful indigo dye.
The method I used was to place the jars in large soup pots filled with water, but raised them off the bottom of the pots with a trivet, to achieve a double boiler effect.
After about 20 minutes, I decided to strain the liquid to remove the leaves, then put the liquid (which was now a brownish color) back into two one-gallon jars. I slowly heated the pots on my gas stove until the dye bath reached 120° F and then I poured the liquid into a large white bucket.
In order to adjust the pH, I added 4 tsp. of baking soda to the two gallons of liquid, and then I vigorously wisked the liquid (with a stainless steel wisk) for a few minutes until frothy blue bubbles formed on top. I later heard that it’s good to scoop the bubbles off the top, but this time I didn’t.
For the next step, I dissolved 2 Tbsp. of color remover (Thiourea dioxide, purchased from Dharma Trading Company) into the liquid. This is intended to remove the oxygen from the dye bath, which is necessary when dyeing with indigo. According to what I had read, the dye bath was supposed to turn a yellow-green color, but it still looked dark green, so I added another 2 Tbsp. of color remover and let it sit for an hour.
I wet an 8 oz. skein of Gaia organic wool, squeezed out the water and immersed it in the dye bath for 20 minutes. It’s thrilling to remove the wool carefully from the dye bath, so as not to add oxygen, and then watch it turn blue as the air hits it! I then let the yarn hang on the clothes line for half an hour. It’s probably not the best idea to dye such a large skein of yarn, as the dye doesn’t reach all the strands evenly, so to compensate, I moved the ties on the skein before I immersed it for a second time. Again, I let it soak for 20 minutes, and then let it air for half an hour before rinsing with clear water.
I also experimented with dying a chartreuse cashmere sweater that I found at a thrift store, but it came out a bit splotchy, so I will be dyeing it again another day.
I would not recommend letting the leaves soak in the jars for more than one day, as the smell of the liquid affected my yarn and took several washings to remove. Since then I have made two additional dye baths after letting the fresh leaves soak for just 24 hours, and it worked fine.
More to come about subsequent dye baths and experiments, plus a fabulous class on shibori with indigo and madder, taught by Ana Lisa Hedstrom.
An important footnote: The World Bank estimates that 17 to 20 percent of industrial water pollution comes from textile dyeing and treatment. They’ve also identified 72 toxic chemicals in our water solely from textile dyeing, 30 of which are cannot be removed. This is one of the main reasons it’s crucial to renew interest in natural dyes and locally sourced fibers. See Rebecca Burgess’s “Fibershed Project” blog for inspiration.