POPCORN’S SECRET INGREDIENT: STEAM

The baking scent of cinnamon rolls in the mall, the aroma of brownies nearly ready in the oven and roasting coffee beans in the café are scents that surround you with anticipation of intense pleasure while hinting a failure in will power. The popping of popcorn kernels attack your senses with triple weapons: heavenly scents, pleasing popping sounds of anticipation and the amazing sight of the tiny kernels turning into snowy fluffs ten times the original size. And perhaps the hope of a good movie to come.

Butter-flavored popcorn you buy at the movies has no butter, just butter flavor through an added chemical called diacetyl. (This chemical may produce a rare disease called bronchiolitis obliterans in the lungs of workers working with popcorn, and if you inhale microwaved butter-flavored popcorn a lot, you may be a victim, too.)

Popcorns are treasured American snack foods loved by just about everyone, nearly as much as ice cream. Popped corn is pleasing to eat having soft, tender mouthfeel, lovely appearance and a real treat on taste buds especially when the fluff is enriched with a touch of real melted butter and a light sprinkling of salt.

Raw popping corn on the cob looks just like dried corn-on-the-cob corn with some difference in its composition that enables each kernel to produce mini explosion when heated, then turn into popped corn. The difference is in a tiny amount of moisture entrapped in the center within a starchy mass called endosperm, which is the bulk of corn kernels. This starch is what turns into the white fluffy popcorn. There is a tough protecting skin, the pericarp, surrounding the starch endosperm, so tough that the corn may be preserved for centuries, even millenniums, without any change inside.

It is the tiny moisture and tough skin that enable the kernels to pop when we impose intense heat on them. Over the high heat the starchy mass melts to become a viscous fluid while the moisture turns into steam creating a miniature pressure cooker. There is no safety valve on this cooker, and when the tough skin is no longer able to withhold the still building pressure, at a critical point it ruptures, spilling the starchy thick liquid that instantly solidifies in the air and swells into the familiar and unique popcorn shape.

Pop Your own

In 1946 the scientist Percy Spencer working for the Raytheon Corporation placed some popcorn under microwave radiation in his lab and to his surprise the popcorn popped in a few minutes. Subjecting other foods to microwave Spencer discovered that they cooked in seconds. From this simple experiments microwave cooking was born.

More than half a century later microwave is still in use for popping corn. In addition, there are all sorts of popcorn poppers to choose from, dozens and scores, and they are convenient to use. But a heavy covered skillet on the stove top works as well as any without taking extra kitchen space if you are willing to do the manual popping. Skillet popping, however, will not give you the largest yield. Sabri Gökmen, Department of Crop Science, University of Gaziosmanpasa, Turkey, determined that microwave gives the largest flakes but also the largest unpopped kernels because of microwave’s uneven heating.

If you are old school and want to use a skillet, here is how to do it.

Have the popcorn ready, measuring three to four tablespoons of kernels for a serving and your choice of vegetable oil. Don’t use olive oil that burns on high heat or butter that burns at an even lower temperature but you can use clarified butter for heavenly popcorn. Measure out one teaspoon oil per serving fine salt. Fine-ground popcorn salt is ideal because it sticks to popcorn better (easy to make: grind salt for a few seconds in a mortar with a pestle.)

1. Heat the skillet over high heat until it just begins to smoke. At this point its temperature is at least 400 degrees. Pour in the measured oil then swirl it in the pan to cover bottom and let it heat for a few seconds then dump in popcorn, cover the skillet. In a few minutes the kernels heat up to the critical temperature at which time the internal steam bursts the kernels open. Now the comforting popping sound lets you know that the kernels are working. Start shaking the pan without opening the lid and as soon as popping subsides, remove the pan from the heat, wait for a few more seconds then uncover and pour popcorn into a bowl.
2. If you like your popcorn buttered, add one to two teaspoons butter per serving into the hot skillet while off the heat, let butter melt then return the popcorn, stirring well to distribute the butter evenly. Shake salt over popcorn, stir and serve.

Popcorn kernels must have 13 to 14 percent moisture or they won’t pop. Keeping the kernels in a tightly sealed container ensures that the moisture remains sealed inside each kernel. Experts say that popcorn only keeps for about a year. Sometimes experts are wrong. Popcorn stored for a decade or more pops perfectly well. If you have stored them too long, however, listen to popcorn expert Kenneth Ziegler. Sprinkle a jarful of popcorn kernels with a tablespoon of water, shake well, tighten lid and let them sit for four to seven days on your counter, shaking the jar when you remember. Lost moisture is restored and the kernels should pop as programmed.

You don’t need to wait for your next trip to the movie theater—popcorn is a great snack any time and reasonably healthy, provided you don’t drown it in butter and salt.