YOU ASKED: I started reading India Flint’s book Eco Colour. She mentioned that whey could be used as a mordant but didn’t say how. I do make cheese on occasion and am always looking for something to do with the whey. Have you ever used it? If so, how?
KATHY ANSWERED: Whey is usually acidic and contains protein and minerals. It might be considered one of those ingredients that helps dye molecules attract to fibers, like casein (milk protein), soy milk, blood, and egg white. All of these ingredients are used historically in other cultures to help dye stuffs and even pigments adhere to cloth. Of course, soy milk is a popular alternative binder for natural dyes and pigments today. I think if you wanted to try to use whey like you would soy milk, you could get some interesting results. Let us know the next time you have leftover whey what happens. It is also supposedly amazing for helping a lacto fermentation process get started, so you could also use it with your sourdough starter or next batch of dill pickles.