HERE (http://www.thehistoryblog.com/archives/60911) is a link to a fascinating article on fermented wool.
No, seriously. I’ve said many times that “fermentation is not only proof that the divine exists, but proof it wants us happy”, but until yesterday, I did not know that fermented wool was a thing. Apparently, if you apply wheat bran and sourdough to wool very carefully you can convert the fat in the fibers and make it much more colorfast.
This 2,400 year old rug was unearthed in 1947 in the Altai region of what is now Kazakhstan, and resides in the Hermitage. Detailed study with modern equipment has revealed that the wool was processed before dyeing with fermentation.
Go read the article. You’ll probably learn something, I know I did.
Klabautermann's Hammer 