I've got about 15lbs of saphire unbleached white flour left from my 25lb bulk purchase from 2 weeks ago. While preparing a wonderful zucchini bread recipe I noticed a "sour" smell from my flour.
It's been tightly sealed in the heavy duty bag I purchased it in and stored in the pantry at 70-85°F.
Has my flour spoiled?
What are the storage guidelines for flour?