Congratulations! You grew some indigo plants!

Now what the heck to do you do to get the color out!?

First things first, it kind of depends what you mean by “indigo”. Chances are, you’ve grown only one of a handful of plants that contain enough indigo to actually work with. If you got your plants from me while on tour, then you’re either growing Persicaria tinctoria OR Indigofera suffruticosa OR Isatis tinctoria or a little bit of each. The methods I’m mentioning here apply to the processing of the LEAVES ONLY on these plants. Other indigo species contain pigment in other parts of the plant, but not these.

This page is meant to point you toward a whole bunch of different resources for information about indigo pigment extraction. For the sake of organization, I’m going to break down extraction options into three different categories in order from simplest to most complex: first - direct indican dyeing, second - aqueous extraction of indigotin, third - dried leaves and composting extraction.

I’ll say it now (and say it again later), in my opinion, the best, English language published single source of practical information on many of the processes mentioned on this page is actually a publication by John Marshall which is available in my shop. So if you’re looking for information to demystify the process, start there.

I’m going to throw a bunch of similar words at you which can be confusing but they have different meanings and different uses but it is helpful to know the difference so here we go :

INDICAN - This is a molecule produced within certain plants that CAN be used directly to dye protein fibers.

INDOXYL - An intermediary molecule which easily converts to indigotin in the presence of oxygen.

INDIGOTIN and INDIGO - Used interchangeably, referring to the oxidized pigment molecule which CANNOT directly dye fibers, but requires dissolution and reduction in alkaline solution called a vat to be able to penetrate and adhere to cellulose (plant) or protein (animal) fibers.

1. Direct Indican Dyeing

for dyeing directly onto Silk and wool fibers

This is the most simple means of extracting pigment from indigo leaves. For those of you who have seen a indigo leaf, you may have noticed that it is not blue! That’s because there is not actually ‘indigo’ in the leaf but actually two precursor molecules that need to combine to form indigo. Sometimes, when the leaf is bruised, frostbitten or bug-bit you’ll notice that portions of the leaf DO turn blue. This is because the cell structure of the leaf that normally keep the two indigo ingredients separated has been ruptured, allowing them to combine and (in the presence of oxygen) form indigo.

The two ingredients are Indican and an Enzyme that digests indican. Indican itself is water soluble and actually able to dye protein fibers (silk, wool, spider webs, eggs, vicuña fur, porcupine quills, what have you!) But it is typically short-lived once it is smashed or soaked out of a leaf because it is quickly digested by the enzyme into another molecule which does NOT dye fabric in the same way. Direct indican dyeing works within the limited amount of time that the indican exists (in our oxygen rich atmosphere). There are a couple methods of effectively slowing the enzyme so the dyer has a longer time to work with this pigment.

HAPAZOME : Directly Compressing Leaves onto Fabric

Salt Rub Dyeing

Ice Cold Fresh Leaf Extraction

  • John Marshall covers this process in Singing the Blues

  • Liz Spencer has a lovely post with photographs here: http://www.thedogwooddyer.com/blog/2014/9/27/fresh-leaf-indigo-dyeing

  • Here’s a nice Turkey Red Journal article on dyeing wool : http://www.turkeyredjournal.com/archives/V13_I2/cadoret-braunschweig.html

2. Aqueous Extraction of Indigotin

To Create indigo Extract which can be stored indefinitely and Activated in vats to dye any type of fiber

3. Dried Leaf Extraction

to be stored indefinitely and activated in vats for dyeing any type of natural fiber

Couching or Secondary Composting

Sukumo Production

Boiled Extraction from Dried Leaf Powder