Popcorn does not come from the same plant as sweet corn often used for corn on the cob. The University of Missouri recommends specific popcorn varieties best suited for home growing and drying: hybrid South American mushroom, Japanese hull-less, white cloud, creme puff hybrid and dynamite. Depending on the area of the country in which you live, you might have to harvest the corn early because of heavy autumn rains. Mother Earth News suggests that popcorn dry on the stalk if possible, but you can still dry the popcorn yourself if you must harvest early.
Pick the ears of corn only after the kernels become hard and the husks turn dry and papery.
Pull the husks off the ears and discard.
Heat your oven to 300 degrees Fahrenheit for 20 minutes and arrange the ears in a single layer on a roasting pan. Turn the oven down to the lowest setting, 200 degrees or below, and place the roasting pan into the oven with the door ajar.
Leave overnight to dry the ears. Alternatively, place the ears of corn into a mesh bag and hang in a cool, dry place for one week until the kernels become dry.
Place the dried ears of corn into zip-top freezer bags and store in the refrigerator or freezer. They can keep for up to 30 months.
Put an entire ear of dried corn into a paper bag, fold over the top to close and tape the bag down. Microwave on high power for two to three minutes or until the popping sounds slow to two seconds between pops.