@evelyninthegarden I had to Google coffee Silverskins too!
https://www.sciencedirect.com/...
Coffee silverskin (CS) is the only by-product produced during the coffee beans roasting process, and large amounts of CS are produced by roasters in coffee-consuming countries. However, methods for the effective utilization of CS have not been developed. Reuse of CS, which is the primary residue from the coffee industry, is important for the environment and economy. Recently, there have been some attempts to reuse CS for biological materials and as a nutrient source for solid-state fermentation.
