The fracturing and friction of coffee beans during grinding generates electricity that causes coffee particles to clump together and stick to the grinder. Researchers report Dec. 6 in the journal Matter that coffee beans with higher internal moisture produce less static electricity, which means less coffee is wasted and there is less mess to clean up.
Use a mister bottle and give your beans one(1) spritz per 20 grams. In those cases the amount of water should be small enough that it will completely dry before rust can develop