Popcorn is one of America’s truly native foods. Even before Columbus set sail for the New World, Native Americans were popping corn in shallow clay pots. Today, Americans eat 63 quarts of popcorn per man, woman and child each year. And while movies and popcorn seem to go together, theaters are not the largest users of popcorn – approximately 70 percent is purchased by consumers at retail stores in both raw and popped form and eaten at home.
How healthy is all this popcorn? Like most foods, it depends on what you put on it and what you eat with it. Plain popcorn is a nutritious, low-calorie snack. However, drenched with butter or margarine and doused with salt, popcorn begins to fall out of favor with nutritionists and dietitians. Add sugary syrups and you have a snack that promotes cavities.
Prepared via the air-pop method in a microwave oven or with an inexpensive air-pop machine, a cup of plain popcorn contains fewer than 30 calories and is virtually fat and sodium free. It’s also a good source of fiber (about 2 grams per cup), which adds bulk and thereby makes this nonfattening food quite filling.
But every tablespoon of oil used for popping adds around 100 calories, as does every tablespoon of melted butter added after popping. Over two-thirds of the popcorn sold today comes already buttered and salted and ready to microwave-pop in 2 to 3 minutes. Calories for microwave popcorn vary from 40 per cup for "light" varieties to 60 or 70 per cup for "regular" versions. Sodium levels also vary highly from 50 to 150 milligrams per cup.
If you’re interested in controlling the fat and salt in your popcorn, start with plain kernels and an air-pop machine. The two main types of popcorn, yellow pearl and white rice, pop differently. Yellow pearl kernels produce a greater volume of popcorn per kernel than do white rice ones. On the other hand, white rice popcorn does not produce any hulls that stick in your teeth.
How well your popcorn pops depends to a great extent on the moisture content of the popcorn and the temperature of the popper. A moisture content of 14 percent seems to work best when popping corn with oil in an electric popper. Slightly higher moisture content is 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 has been 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 one percent. Although that may not sound like a lot, a loss of 3 percent can render the popcorn unpoppable. In Colorado’s dry climate, 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 one tablespoon of water. Cover and shake frequently, every 5 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.