Dry Popcorn for Storage
Pick popcorn when the stalks are dried out. If you have an accurate way to test moisture content, you can time it more precisely. The University of Wisconsin Extension Service suggests harvesting popcorn ears by hand anytime after it reaches 35% moisture and before the first hard frost.
Check to see if the popcorn is ready for harvest by stripping the husks from a sample or two. The kernels should be hard and nearly dry. If the corn appears ready, pick the corn, then strip away the dried husks.
Cure the corn in a warm dry place for four to six weeks. There are a number of methods to finish curing popcorn after harvest. The easiest way is to cover concrete floor with a canvas tarp and spread the popcorn ears in a single layer over the tarp. A popular alternative method is to place the popcorn ears in a mesh bag or nylon stockings and hang them from the rafters of a warm, dry attic or garage room.
Store dried ears in mesh bags hanging in a root cellar or other cool, dry place if you prefer to store the dried ears whole. Popcorn will keep for years under those conditions
Remove Popcorn Kernels from the Ears
Wearing gloves to protect your hands, grasp the ear of popcorn firmly at each end.
Twist your hands in opposite directions until the dried kernels begin to pop off. Once the kernels have started falling off, they'll come off easily.
Remove any remaining kernels by rubbing your hands up and down the ear of popcorn.
Pop immediately or store your popcorn in airtight jars until you're ready to pop it. It will remain fresh for months stored this way.