These last months, a time when I would usually be traveling and teaching, I have found myself immersed in studio and garden. We are healthy and thankful for that.
I am also grateful for the extended time to spend learning more about indigo fermentation. Over these last months I have made dozens of small test vats in the quest to better understand how the vats work and how to maintain them. These small vats have given way to a three 50 liter vats that are healthy and dyeing beautifully.
All of my vats use indigo pigment from Stoney Creek Colors, plus organic material to produce fermentation and thus, reduction.
As part of the experimentation and study, I have successfully made my own wood ash lye and worked with both soda ash and potash as alternatives. All of these sources of alkalinity work with these vats. I have almost eliminated the use of lime, except as an occasional addition to adjust the pH.
Each of the small indigo test vats (mostly 1 liter) are designed and made to answer a single question such as:
- How long does it take a vat to go into reduction?
- Does fresh ground madder root behave the same as “spent” madder root?
- What is the effect of applying heat?
- How much heat?
- Can soda ash be substituted for wood ash lye?
- Can potash be substituted for soda ash?
- Will “seeding” a new vat with a small amount from an older, reduced vat speed up the reduction process?
- What is the effect of additional indigo plant material when added to the vat?
- ground woad balls
- dried Persicaria tinctoria leaves
- patties made from Indigofera suffruticosa leaves
- Can I make a fermentation vat without adding indigo pigment? All the indigo would then come from the plant material that also causes the fermentation.
- Can I leave a vat unattended for a week? 2 weeks? 3 weeks? how long?
- What is the best way to get the vat back into a healthy reduction after it has been ignored and the reduction is weak or non-existent?
- What is the best way to make a weak vat for pale hues?
- Can a fermentation vat be done successfully using synthetic pigment? – I was not successful at this!
Small samples are dyed daily in the sample vats and I monitor both the pH and the temperature of the solution. I also take note of both the vat surface and its smell. Once I feel “confident” that I have learned the lessons that each experiment has to teach me, I add the small vat to one the large ones. This replenishes the volume and adds some organic material.
Making the first “large” vat took courage and a leap of faith. I now feel ready to double the size.
Several years ago I began growing small amounts of indigo in my garden, simply to understand it. I knew it would never be practical to extract my own indigo pigment. Now I have found an important use for even the small amounts of those fresh indigo leaves as source material for indigo balls or dried leaves to be added to the fermentation vats.
Earlier this month I “attended” a “Zoom” talk by Aboubakar Fofana in which he talked about his own indigo practice. It was hosted by Botanical Colors. I think it is well worth you time and now available online.
The indigo research and opportunities to attend virtual lectures have become possible because of this focused time at home. Now, it’s time to go back to the loom and prepare some woven shibori textiles for dyeing!