<<Disclaimer: Verify this information before applying it to your situation.>> Hi Listmates I've been milling my own flours in a very sturdy german made mill. It takes almost everything, but remember the following caveats: Never ever mill tapioca granules! Your mill will be messed up and will need being taken apart in order to clean the stones - big mess !!! Oily grains are best milled if mixed with something dry, say rice. In most cases, the flours are used in a mix, so there is no problem with "pure" flours anyway. Quinoa and amaranth are tiny, hard grains. They tend to give a sandy texture, unless they are introduced in little ammounts. If your mill can be set to accept various ammounts of grains at a time, choose small quantities or fill in the grains a teaspoonful at a time. Keep your mill free of gluten grains! Happy holidays from Christian, Basel, Switzerland