How long does soy flour last?

How to tell soy flour has gone bad

General signs for vegetarian proteins, the group USDA lists soy flour under.

• Sour or off smell instead of a neutral, mild scent
• Slimy film developing on the surface of tofu
• Discoloration, especially yellowing or dark spots
• Mould, often black or white, on tempeh
• Packaging that has swollen or lost its seal

More on vegetarian proteins. The times above are quality guidelines, not safety limits; food that shows these signs goes out regardless of the date.

Storage habits that make the difference

Refrigerate opened tofu submerged in fresh water in a covered container, changing the water daily, and use within about a week. Keep tempeh and meat substitutes in their sealed packaging until use, then reseal tightly. Freeze extra tofu or tempeh in an airtight container for longer storage; the texture will change slightly.