As I mentioned in my previous post about a dyeing workshop I recently attended, one of the dye sources was black beans. The sample I took away from class was a light blue, but the sample I brought home turned out light green. I'm guessing one of the wooden spoons was contaminated with copper (from the mordanting of a different yarn sample).
The hibiscus tea flowers I brought home from the workshop were disappointing - the result was taupe. The photo below shows undyed yarn lying on top of unmordanted dyed yarn. It is not a black-and-white photo.
SO... I decided to overdye the yarn with henna, which I purchased at Fresh Thyme in their hair dye section. I chose the variety with only henna in it, using 4 ounces of henna for 8 ounces of Lambs Pride wool. Then I threw a couple of one-ounce skeins into the exhausted dye bath. The result is two lovely shades of brown.
After "cooking" the henna, I strained the dye bath through some cotton cloth before adding the yarn. Since the cotton cloth was basically partially dyed from this step, I threw it into the exhausted dye bath as well. The results were uneven (and more tan than this photo indicates).
One thing I learned from this post-workshop experience is not to leave yarn in an eight-ounce hank when dyeing. I was too lazy to rewind it into two four-ounce skeins, but eight ounces is just too much wet wool to wrestle with, especially when rinsing, then spinning in a salad spinner. I considered experimenting with different after-dye processes, but by the time I reached this point, I was done with dyeing... for a while.