A Simplified Look At The Science Behind Why Popcorn Pops

People have been enjoying popcorn for thousands of years however what made them pop has been subject of curiosity for many.

In the olden days, ancients attributed wha happened to tiny gods trapped within the kernel that would burst with anger when heated.

However  we now know that the actual reason why popcorn pops is a fascinating mix of chemistry and physics. It starts with the kernel.

Popcorn kernels have two layers. The construction and composition of corn kernels are the properties that create the conditions needed for popping.

The outer layer is the light yellow, transparent hull, and it is what really gets corn popping. When intact, the hull repels moisture which means none will be released until the hull is breached. This acts as a pressure vessel during popping.

Within the hull is the endosperm. It is comprised of a hard starch and a small amount of moisture (approximately 14 percent). It is rock hard before it pops.

Why Does Popcorn Pop?

When the popcorn kernel gets heated, the small amount of moisture caught in the kernel transforms into steam, which is then pushed past the boiling point by the pressurized environment created by the hull.

The pressurized heat gelatinizes the hard starch and turns it from rock solid to a very malleable form.

As the kernel continues to get hotter , the pressure eventually exceeds the strength of the hull, which causes the hull to rupture.

At that point, the pressurized steam within the kernel immediately expands and causes the gelatinized starch to puff in the process.

As the steam escapes, the temperature of the starch drops rapidly, allowing it to once again take solid form. The end product is a perfectly fluffy, popped popcorn kernel.