Hi everyone, first post though I've been soaking up your knowledge for months.
I grew woad this year (UK) to colour my soaps and extracted the blue pigment from the leaves. I used the method of processing the leaves within an hour of picking. Tear the leaves and put into 90C water (with lid on) for 10 mins then squeeze the water out, mix in soda crystals then stick blend for a while. Let the bits settle then take out the top water and put more fresh water in, leave to settle, repeating until the water is clear. Then remove as much water from the top as possible and dry the paste until totally flaky and dry. Grind into powder and you're done.
It works but I didn't get a massive amount of powder, though I harvested a month too late. It works great though. Beautiful deep blues or pale pastel ones, no grey. I'll harvest again in the spring and hopefully get a better yield.
I couldn't find the page I followed but this is the same method:
http://www.thomaskeyes.co.uk/index.asp?pageid=689263
Glad to be here with you all - I've learned so much thanks. Sam