How well your popcorn pops depends mostly on the moisture content of the popcorn and the temperature of the popper. The ideal popping temperature is between 400 degrees and 460 degrees Fahrenheit. A moisture content of 13.5 percent to 14 percent seems to work best when popping corn with oil in an electric popper. A slightly higher moisture content may be helpful for dry popping in an air-popper.
Popcorn that has been processed by a reliable processor and packed in an airtight, undamaged container or package should be at the proper moisture level for perfect popping. Once the package is opened, the unused portion should be stored in an airtight container such as a glass jar to help preserve the natural moisture. Left uncovered on a hot day, the moisture content of the kernels can drop as much as 1 percent. Although that may not sound like a lot, a loss of 3 percent can render the popcorn un-poppable. It is generally recommended that popcorn be stored in a cool, dry cupboard. However, in some dryer climates, some people report better keeping quality when popcorn is stored in the refrigerator.
If your popcorn doesn’t pop into fluffy, crisp kernels, its moisture content has probably dropped too low. To recondition the kernels, fill a quart jar three-fourths full with dry popcorn kernels and add 1 tablespoon of water. Cover and shake frequently, every five or 10 minutes, until all of the water has been absorbed. After two to four days of storage in the closed jar, the corn should again be ready for perfect popping.