Unpopped popcorn kernels are best stored in an airtight container, such as a sealed plastic bag or a glass jar with lid. Once you've opened the commercial packaging, it's a good idea to transfer unused popcorn kernels to the glass or plastic airtight storage container. Store such popcorn kernels in a cool, dry place. Once popped, popcorn can be stored in an airtight container or in the freezer but you'll find more instructions for freshly popped popcorn in the wikiHow: .