Believe it or not, there is more to popcorn than just good looks, sounds, aroma and flavor – there's a lot of science in those little kernels! So, what's the secret behind those hard little kernels that suddenly burst into crispy, flavorful morsels?
Popcorn is made up of starch and a small amount of moisture that is locked inside the kernel's hard shell, called the enamel coating.
As the cooking temperature rises to about 450° F, the moisture inside the kernel turns to steam and pressure begins to build. The steam, now surrounded by normal-pressure air, becomes the driving force that expands the kernel.
When the enamel coating cannot withstand the force any longer, it "POPS!"
The starch granules do not actually explode, but expand into thin, jelly-like bubbles. Neighboring bubbles fuse together and solidify, forming a three-dimensional network – much like a sink full of soapsuds. This is the white, fluffy, solid material we call popcorn!