All foods go past their prime, but technically, you can eat expired popcorn. Don't be surprised if the kernels don't pop properly or the flavor seems stale and "off."

How long your popcorn will stay fresh depends on the type. Unopened bags of already-popped corn will taste fine for two to four weeks beyond their best-by dates.

Once opened, popcorn will taste off in a week or two, or quicker if not stored properly. Unpopped kernels of corn stay fresh indefinitely, though older kernels don't pop as well.

Dry popcorn kernels can be used within six months to a year beyond their best-by dates. Microwave popcorn bags should be fine for three months past the date on the bags.