Q&A for How to Dehydrate Sweet Potatoes

If you keep them in an airtight container, they'll last a couple months.

I wouldn't. Sweet potatoes should be orange. If they are grey, that could indicate mold.

Yes it is. For example, I do this to make dog treats. They take a bit longer to dehydrate since they're thicker than a chip, but they work just as well.

This depends on whether or not oil is used. Any oil will decrease shelf time. I vac seal mine and store in fridge. In the absence of air, they last a long time in the fridge. Be sure there is no moisture in your potatoes before sealing them in.

Yes. Rehydrate dehydrated sweet potatoes (follow package ratio; typically 1 cup flakes to ~1 cup hot water, adjust for texture) until soft. Mash or chop as needed, then proceed with your sweet potato casserole recipe—mix with butter, sugar, spices, eggs/cream as called for. Bake the same, though monitor moisture. You may need slightly less liquid overall or add a splash if dry. For best texture, re-hydrate to a slightly firmer-than-desired state since baking will soften further.

Your sweet potatoes may be getting moldy because they were not dried correctly, or your dehydrator may be contaminated and needs cleaning.