Air popcorn is a type of popcorn that has been popped by exposing it to hot air. A special appliance, known as an air popper, is usually needed for this. Unlike most other types of popcorn, air popped popcorn is not exposed to any oil or butter while it is being popped. Without this extra fat and calorie, air popcorn is much healthier, and popcorn popped with hot air doesn't usually burn like other types of popcorn. Some individuals may find that an air popper is somewhat inconvenient, however, since it needs to be washed and stored after each use.
To understand how an air popcorn popper works, it is helpful to understand what makes popcorn pop. A popcorn kernel consists of starchy fibers surrounded by a hard outer covering, known as a hull. When heat is applied to the outside of a popcorn kernel, the moisture inside the kernel turns to steam. This creates an immense pressure, which eventually causes the hull to pop, releasing the steam and the starchy fibers that were trapped inside.
Before popcorn poppers and microwave popcorn were invented, people simply placed the kernels in a pan or metal basket. Sometimes lard or another type of fat was also used. The container holding the popcorn kernels was held over a heat source, such as a fire, and shaken constantly to prevent the popcorn from burning. Although somewhat successful, this method often caused the popcorn to burn.
The first popcorn popper was invented in the 19th century. This popcorn popper used steam and oil to pop larger quantities of popcorn than ever before. It wasn't until the 1970s, however, that the first air popcorn popper was invented.
An air popcorn popper works by constantly blowing hot air into a cylinder where the popcorn kernels are placed. This hot air not only provides the necessary heat to cause the popcorn to pop, but it also constantly moves the popcorn around, so that it does not burn. Once air popcorn has popped, it is much lighter than the unpopped kernels. This allows them to be blown up and out of the chamber, usually through a chute on the front of the appliance.
Since it is not heated with butter or oil, air popcorn is generally healthier than other types of popcorn, such as microwave popcorn. It therefore has less fat and calories. Also, since the popped kernels are not left to sit on a hot surface for too long, air popcorn is also less likely to burn than popcorn made in a pan.
Some people, however, may see air popcorn as an inconvenience. These machines should usually be washed after popcorn is made, for example. They also take up valuable cupboard or counter space.