How does popcorn pop?

Answer by  Dianamite (109)

When you heat a popcorn kernel, the moisture inside the kernel expands. If the percentage of moisture inside the kernel isn't right, then it won't pop. When the pressure inside the hard shell gets high enough, the kernel explodes, or pops!

Answer by  poohwriter (110)

A popcorn kernal has a small amount of water in the core. To make it pop open you need to heat the kernal until the water inside boils and when it does the kernal will pop open.

Answer by  trudie1962 (1022)

When popcorn is heated, the moisture inside it turns to steam and the pressure of the steam blows the kernel open. This applies to microwave, air-pop and stove-top popcorn you cook in a pot with some oil. The kernel may seem very dry but there is enough water inside it to create the appropriate amount of pressure.