Why does popcorn pop?

Senior Moments

There is a good explanation on http://maize.agron.iastate.edu/popcorn.html Most of the inside of a kernel is composed of starch, which is a storage carbohydrate, or fuel. This starch is known as the seed's "endosperm" (meaning it is inside the seed). Its purpose is to provide energy for the living part of the kernel, the "germ" or embryo, once this embryo germinates and establishes a new plant. Starch has a large water holding capacity, and for this reason it has a number of industrial uses as a dehydrating agent in powder form. When you heat popcorn, the water that is ordinarily bound in the floury endosperm becomes a vapor and bursts through the fruit case, or "pericarp" of the kernel. In order for this to happen successfully and dependably, therefore, the kernel must be relatively small, and the hard, or flinty, outer shell of the kernel must be quite strong to resist the building pressure. This is why popcorn produces grains that are smaller than most field corn. Feb 23 04, 1:45 AM

_princess_007

Popcorn is a kind of corn. A kernel pops when it is heated to 400 degrees Fahrenheit, causing water inside each kernel to change to steam. Popcorn's hard cover keeps the steam from escaping, causing pressure to build up and, finally, pop goes the kernel! http://www.bayerus.com/msms/fun/riddles/popcorn.html Nov 17 06, 2:52 AM