Michigan State University Extension
Preserving Food Safely - 01600285
Popcorn is left on the plant to mature and is ready to harvest when husks are dry and the kernels hard. Pick popcorn before frost, husk the ears, and place in a mesh bag or old nylon stocking to cure. Curing takes 2 to 3 weeks and is done in a warm, dry, well ventilated area. Once cured, shell it and store kernels in quart glass jars. Fill the jars only 3/4 of the way. Seal the jars and store them in the refrigerator. Unshelled corn may be stored at temperatures near 32 degrees Fahrenheit in high humidity. The ears must be protected from rodents. Properly conditioned corn should pop in 80 to 90 seconds. Poor popping may be due to low moisture content. The ideal moisture content is 13-1/2 percent. To increase the moisture content, add 1 tablespoon of water to the jar, reseal the jar and shake it twice a day for 2 days, then take out a sample to pop. If popping is still poor, add more water. Two treatments should be all that are needed. Too much moisture can cause poor popping. If too much moisture is a problem, corn pops with a loud explosion, the kernels will be jagged and tough, and steam comes from the popper. Popcorn should last 3 to 4 years with proper storage.