<<Disclaimer: Verify this information before applying it to your situation.>> With just a few replies I would say - yes, rinse and dry quinao before making your own flour. Answer 1 - If you use our Ancient Harvest Quinoa you do not need to rinse before grinding into a flour. We wash our quinoa in pure water and sun dry it prior to packing. Just remember that although the quinoa has about a 2 year shelf life, once it is processed into flour, it needs to be used within about 6 months so it is best to grind only what you are going to use to make sure it is fresh. If you have any more questions or comments you may E-Mail us at Quinoa Corp. [log in to unmask] Answer 2 - Hi, I would always rinse quinoa, for the reason you mentioned--the bitter saponins--as well as to make sure dirt, and even stray glutinous flours, are not contaminating it, before cooking or grinding. The problem then is, of course, that then you must dry it again before grinding, or risk a gunky mess instead of flour! I would recommend heating it while stirring in a pan on the stove or in the oven until dry, or, even better, use a home dehydrator. It's a lot of trouble, but I think it's the best way. (I haven't tried this with quinoa, but I have done it with rice to make rice flour: takes at least a day, of course.)