What is the white scale on my crusher?

I have asked several wine makers this question and no one seems to know the answer. After crushing grapes, both red and white, my crusher paddles have a white scale on them. The scale can be scrubbed off with a lot of elbow grease but tries to stay permanently attached to the stainless steel paddles. I have flaked it off and it has no discernable odor, is tasteless (yes I did taste it) and is white. If you know what this is, please tell us! I suspect that it is a protein possibly bound to sulfur.