For the hungry snacker, unpopped kernels at the bottom of a bag of microwavable popcorn are missed opportunities. In a constant quest to lessen such disappointments, food manufacturers relentlessly breed corn with their sights set on varieties that pop best. Now, a group of chemists claims to have found that the secret to better popping is the crystalline structure of the kernel's hull.
Stored in every kernel are starch and a bit of moisture. As popcorn heats up, that moisture vaporizes and pressure builds inside the kernel. When the pressure reaches about 9 atmospheres, the kernel bursts. Within milliseconds, the softened starch noisily expands into a white foam.