coffee as dye

Mountain Man recently handed me a pair of white linen trousers. He told me he never wears them, and he asked me to dye them. Yay! I love a dyeing challenge.

The reason it was a bit of a challenge is that plant fibers are much less receptive to natural dyes than animal fibers. They usually require a labor-intensive series of mordants, and even then they often don't come out with the same pleasing colors.

I decided to search for a substantive dye, which is one that requires no mordant. I thought about pecan hulls and tree barks, but I settled on the nearest one at hand: coffee. (A big thanks goes out to Mama Java's, our local independent coffe house, for collecting some grounds for me.)

Before I got to the main event, I wanted to do a little experimentation. I set up two dye vats: (1) one for the stovetop, with a conventional 1-hour simmer of dyestuff and 1-hour simmer of fibers, and (2) one for solar dyeing, with a 2-day soak of the coffee grounds and a 2-day soak of the fibers. I made mini-skeins of wool, handspun alpaca, and cotton yarns for each vat, and I added a silk skein to the conventional vat as well. The results:

Left to right: tussah silk, conventional wool, solar wool, conventional alpaca, solar alpaca, conventional cotton, solar cotton.
Overall, I was pleased with how the solar dyeing compared to the stovetop dyeing. It produced slightly lighter colors, but it was free, carbon-free heat.

I love the caramel color that came out on the silk and wool. You'll notice, though, that the cotton just came out looking dirty. Had me a bit worried for those trousers, but I tried them out anyways, solar-style (that was the lesson I took from the experimentation). And, reasonable success!
I did two rounds of solar dyeing on them, and they came out a light khaki color, a little warmer than it looks in the photo above. I had to agitate them in the dye pot (basically, plunging my hands in every couple of hours and giving them a good scrub) pretty often in order to get the color even. Both my hands and the fabric seem coarser after all that, but it was worth it. Now Mountain Man has a pair of pants he can spill coffee on with impunity!