The Secret Science of Popcorn

Cool Chemistry

Can any corn become popcorn?

Not all corn pops! Popcorn is a special type of corn. Some other grains, such as quinoa and sorghum, can pop too; but popcorn is the biggest and best popper!

Popcorn

 

How big does popcorn get?

This picture shows 200 kernels of popcorn in a 1000 mL graduated cylinder and 200 pieces of popped popcorn in another. Popped popcorn typically fills about 40 times the space it did when it was just a pile of kernels.

Cylinders of Popcorn

 

Why is some popped popcorn rounder-looking than other popcorn?

Popcorn comes in two basic shapes— butterfly and mushroom. Butterfly popcorn has a very irregular shape with large bumps. It has a light crispy texture but can break easily. The mushroom-shaped popcorn is round with a rough surface. This shape makes it sturdy enough to stir and as you add tasty flavorings such as powdered cheese or sugar for sweet-tasting kettle corn.

Buterfly and Mushroom types of popcorn

Why does steam come out when you first open a container of hot popcorn?

Be extra careful when opening a bag, foil dome, or even removing the lid off a pot of freshly made popcorn! Why? The water vapor, which burst out of each kernel, is in the container and is very hot. You might see the water as it condenses into swirls of smoky steam. Here you can see it over a pot of popping kettle corn.

Kettle Corn