Dyeing with back beans is very simple. You soak the beans for at least 12 hours, you strain off the soaking liquid and put the beans aside for cooking. Then you use the murky soaking liquid to dye your fiber. Note: Never use dyeing equipment for cooking food. I used a kitchen bowl to soak the beans and then a dye pot to dye the fiber.
|Cover beans with about two inches of water|
Some people like to dye the fiber with the beans, but then they can't eat the beans and I find that to wasteful. If you want a strong blue just soak more beans. You can always freeze the pre-soaked beans for later.
|This skein has just been pulled from the bath|
Heat will destroy the blue color, so all you have to do is put your pre-wetted fiber into the bowl and wait. Black bean dye is very sensitive to pH, so you can play around with the color by adding a little baking soda or vinegar. My tap water is alkaline and so I got a beautiful bright blue. It also seems like black bean dye works best on superwash wools.
|Left to right 1st bath and 2nd bath|
|Weld dyed Shetland wool over dyed with back beans|
I used 1k of beans to dye 200g of alum mordanted BFL and nylon superwash sock yarn. I probably could have dyed a lot more fiber, but I'm almost out of alum mordanted wool and didn't want to use up too much of my stash. I dumped the spent bath into my flower garden.
|This is the most accurate picture of the blue color|
Black bean dye is not very light fast, and is very sensitive to heat. I recommend minimal washing in cold water only. Be sure to dry your dyed fiber in a shady place.