Today I harvested 1050 grams (2.25 lbs) of Japanese Indigo (Polygonum tinctorium, also known as Persicaria tinctoria). Here is the 2 gallon bucket with the cut stems:
I picked off the leaves into a gallon plastic bag for weighing, then cut them up with kitchen shears:
and stuffed them into a half gallon canning jar and filled it with warm water. Then I put the jar into a canning pot on a hotplate set to heat no higher than 100F to let it ferment overnight:
The next bag (250 g) I put into a 2 1/2 gallon plastic bucket with cold water. I'll add vinegar and macerate by hand to extract the color:
I also have 250g in a yogurt maker with water but it doesn't seem to be heating up much. I should have started with warm water. This is supposed to ferment too. I have just read a recipe for dyeing the fiber right away in the fermented liquid without beating it to oxygenate and then reducing it again. The fermentation splits the indican into indoxyl and glucose with carbon dioxide escaping as bubbles.