When you pop corn kernels in a microwave oven, the kernels undergo a process called "thermal expansion," leading them to burst open and transform into fluffy, edible popcorn. This process occurs due to the buildup of steam inside the kernel as it heats up. Here's what happens step by step:
Heating: When you place a bag or bowl of popcorn kernels in the microwave and turn it on, the microwave's electromagnetic waves penetrate the kernels and start heating them up. The water content inside the kernel begins to heat and turn into steam.
Steam Buildup: As the heat increases, the water inside the kernel turns into steam. Since the steam cannot escape the kernel's hard shell, pressure starts to build up inside.
Pressure and Expansion: The pressure from the steam continues to increase until it becomes strong enough to rupture the kernel's outer hull. As the pressure builds, the kernel expands rapidly.
Pop! The kernel finally bursts open with a "pop" sound, and the steam inside rapidly expands, creating a fluffy, white piece of popcorn.
Continued Popping: The popping process typically happens very quickly, and you'll hear multiple pops in rapid succession as more and more kernels explode.
Fluffy Popcorn: Once the popcorn has popped, it becomes light and airy, transforming from a hard, dense kernel into a fluffy, edible snack.
It's essential to follow the manufacturer's instructions when microwaving popcorn to avoid burning or under-popping. Microwave popcorn bags often have predetermined cook times and power settings for optimal results. Overcooking popcorn can lead to burning or scorching, while undercooking may leave unpopped kernels.
As with any microwave cooking, be cautious when handling the popped popcorn, as it will be hot. Allow it to cool for a short time before enjoying your freshly popped snack.