Popcorn, also known as popping corn, is a type of corn that expands from the kernel and puffs up when heated. Corn is able to pop because, like amaranth grain, sorghum, quinoa and millet, its kernels have a hard moisture-sealed hull and a dense starchy interior. This allows pressure to build inside the kernel until explosive “pop” results. Some strains of corn are now cultivated specifically as popping corns.
There are many techniques for popping corn. Commercial large-scale popcorn machines were invented by Charles Cretors in the late 19th century. Many types of small-scale home methods for popping corn also exist, along with prepackaged popcorn. Depending on how it is prepared and cooked, some consider it to be a health food while others caution against it for a variety of reasons. Popcorn can also have non-food applications, ranging from holiday decorations to packaging materials.