Microwave popcorn

Microwave popcorn is a convenience food consisting of unpopped popcorn in an enhanced, sealed paper bag intended to be heated in a microwave oven. In addition to the dried corn the bags typically contain cooking oil with sufficient saturated fat to solidify at room temperature, one or more seasonings (often salt), and natural or artificial flavorings or both. With the many different flavors, there are many different providers.

Design

The bag is typically partially folded when it is placed in a microwave, and inflates as a result of steam pressure from the heated kernels.

The design of a microwave popcorn bag is specifically keyed to avoid popped kernel scorching, an undesirable effect that takes place when popped kernels are heated above 300 °F (149 °C).

A susceptor, usually a metalized film laminated onto the paper of the bag, absorbs microwaves and concentrates heat at the film interface, thus ensuring a heat distribution focused on the hard-to-heat flavor coating so that the unpopped kernels are evenly coated prior to popping, thereby ensuring even flavor throughout the product. Additionally some popcorn is flawed and will not pop because of possible damage to the shell which allows the steam to escape. These unpopped kernels are known as "old maids" or "spinsters".