From Popcorn Kernels to Popcorn

Popcorn is one of the most popular American snack foods. Since its inception in the late 19th century, many people cannot imagine enjoying a show or a movie without it. How often do we think about why popcorn pops? The movement from popcorn kernels to popcorn is more complex than you think.

How it pops

A popcorn kernel is a corn seed. It has a hard, glossy shell on the outside with a soft, starchy material inside that provides energy to the growing plant. This inner material also holds water for the seed. If a kernel is heated to a high level of 400 degrees Fahrenheit, the water turns into steam. The steam creates pressure and the kernel explodes, with the starch bursting out to about forty times its original size. At that point the kernel is left inside, and what you see is that wonderful white fluff that tastes so good - especially with butter, salt or caramel.

Why it doesn't

There are probably some unpopped kernels sitting at the bottom of the bowl; this is because they likely dried out in storage. A good popcorn kernel contains about 14 percent moisture, so that proper storage of unpopped kernels is in a sealed jar or reusable tin. No matter what, a dry kernel does not pop.

The average American consumes nearly 52 quarts of popcorn a year. Popcorn is eaten throughout the rest of the world, although not all countries consider it an essential part of the movie experience. Popcorn is truly all-American; most of the popcorn in the world comes from the United States.