After internet searching this I see two reasons- pine nuts and pregnancy. I am not pregnant and do not believe I had pine nuts recently unless it was in something and I don't know about it. It's a kind of bitter, chalky feeling I've had for 2 days now. It is not metallic. Even when I brush my teeth I get it. It goes away for a bit but lingers quite awhile after I eat. Any suggestions on how to get rid of it or what it could be?