What the hell IS that?

I have a mystery substance in my kitchen cupboard.

See, I have a lot of unusual flours and other products on hand to help me live a gluten-free life. And I buy them in bulk, since it's cheaper that way, and when was the last time YOU saw a pre-packaged container of xanthan gum or sorghum in the store?

Anyway. All this stuff is stored in plastic bags, which I carefully label. You know, on those white labeling spaces on those ziploc bags I buy at Costco.
But the writing has somehow come off of one of them... and I have no idea what that grayish/beigeish powdery substance inside is. There's a lot of it, which suggests I don't use it very often...

But am I really gonna have to examine each bulk bin at Rainbow to figure out what the hell it is?


Say it with me, people: "DORK!"