So, I recently acquired a soxhlet extractor to help with my apothecary work, and I'm having an issue. I'm using ethyl alcohol as my solvent, and shredded spearmint as my extraction substance. As the system runs, it does exactly what I expect: The ethyl boils gently, evaporates, and then condenses with seemingly little to no loss in the upper chamber. Then the reliquefied, but hot, solvent soaks in the spearmint leaves, turning a deep, but transparent, shade of green as the chamber fills completely.
The problem comes once the solution peaks the gravity loop and drains back in to the base liquid. The compound turns a milky, opaque shade of green, then steadily turns a greyish-black over the span of the next several rounds.
I'm sure I'm just doing something wrong, but since this is my first time using any extraction process that involves actual lab equipment, I'm at a bit of a loss as to *what* I'm doing wrong.