Adults have many reasons to love popcorn. It’s a whole grain, it’s naturally low in fat and calories, and it adds fiber to the diet.

It smells and tastes great and offers versatility whether you’re craving something salty or sweet.
Kids might like those things, too, but they are especially intrigued by popcorn because of its unique talent in the food world: its ability to pop.

Half the fun of popcorn is watching it turn from a hard, little yellow seed into a white fluffy treat. Few foods take such a dramatic turn as popcorn does while it’s cooking. Standing in the kitchen waiting for your popcorn to finish popping, an awesome spectacle is unfurling before you.

Did you know people have been fascinated by popcorn for centuries? Early Native Americans believed a spirit lived inside each kernel of popcorn. When heated, the spirit grew angry, burst out of its home, and fled into the air as a disgruntled puff of steam.

A less charming but more scientific explanation exists for why popcorn pops.

Popcorn is a whole grain. It is made up of three components: the germ, endosperm and pericarp (also known as hull). Of the four most common types of corn — sweet, dent, flint and popcorn — only popcorn pops. This is because it is the only one that has a hull just the right thickness to allow it to (eventually) burst open.

Each kernel of popcorn contains a small drop of water stored inside a circle of soft starch. Popcorn needs between 13.5 percent and 14 percent, moisture to pop. The soft starch is surrounded by the kernel’s hard outer surface.

As the kernel heats up, the water begins to expand. Around 212 degrees, the water turns ito steam and changes the starch inside each kernel into a super-heated gel-like substance. The kernel continues to heat to about 347 degrees.

The pressure inside the grain will reach 135 pounds per square inch before finally bursting the hull open.
As it explodes, steam inside the kernel is released. The soft starch inside the popcorn becomes inflated and spills out, cooling immediately and forming into the odd shape we know and love. A single kernel can swell 40 to 50 times its original size!

The Popcorn Board, a promotional tool of the popcorn industry, has a video of this transformation set in super-slow motion (captured between 13,000 and 15,000 frames per second).

To view it, visit the Web site www.popcorn.org and click on the Teachers hyperlink.