Buzz
To start, popcorn isn’t your average corn. It's a specially cultivated variety of flint corn called zea mays everta. The kernel itself is considered a whole grain, made up of three components: the bran (the outer hull), the germ (the part that can sprout into a new plant), and the endosperm (the starchy core that nourishes the germ).
Inside the tough outer shell of each kernel, there's mostly soft starch and a bit of water. These elements are key to what makes popcorn pop. When you heat the kernels in a pan or microwave, the water inside begins to turn to steam, expanding in volume. The hard hull holds all that pressure in, acting like a tiny pressure cooker for a short time. The unique structure of popcorn hulls, thanks to the specific alignment of their cellulose molecules, makes them particularly effective at trapping the steam.
Eventually, the pressure from the steam builds up enough to break the hull, causing the kernel to pop. But there’s a fine balance of moisture needed for the perfect pop. If there's not enough water inside, the energy won’t be sufficient to burst the hull, and the kernel will either stay unpopped or just release some steam through small cracks. Too much water, and the result is a dense, chewy kernel instead of a light, fluffy one. Farmers harvest popcorn when the moisture content is between 16 and 19 percent by weight, and then they dry it until it reaches a moisture level of 13 to 14 percent.
As heat and pressure build up inside the kernel, they cause the starchy endosperm to gelatinize and soften. Once the kernel finally bursts, the sudden drop in pressure and the release of steam causes the starch and proteins in the endosperm to expand. The cool air outside quickly sets the expanded starch, forming the light, fluffy flakes that are perfect with butter, salt, or even a touch of Old Bay seasoning.
