Why does popcorn pop?
- yc
- Dec 11, 2020
- 2 min read
Being one of the most common snacks to eat at a movie theater, popcorn comes in various flavors, caramel popcorn, salted popcorn and many more, but have you ever wondered what cause the popcorns to pop?
Ancients believed that tiny gods reside in kernels and cause them to burst with anger when heated, but thanks to scientists, we now know that it is due to the intriguing combination of chemistry and physics that gave kernels their popping ability.
Corn Kernels
If you look closer at a corn kernel, you'll notice that it has two layers.
The first layer is the outer yellow layer called the pericarp or commonly known as the hull. This layer acts as a pressure vessel and an impermeable layer that prevents moisture in the kernel from escaping until it is heated and breaks open.
Then, we have the endosperm which consists of solid starch and a small amount of water. This hard starch is the main reason why a kernel is rock hard before popping.
The Perfect Pop
When the kernel is heated, moisture in the endosperm heats up to become steam which then builds up pressurized heat in the kernel with the help of the hull. This pressurized heat then cause the hard starch to gelatinize to create a very malleable form of starch.
This process then continues until enough pressure is present in the kernel to cause the hull to rupture, allowing the gelatinized starch to burst out as a fluffy white substance. During this event, a popping sound is created and water vapor released from the opened kernel, allowing the temperature of the starch to decrease quickly and take a solid form again. The starch is also one of the reasons why our fingers become slightly sticky after eating popcorn.
Faulty Pops
We all know that there always a few kernels that never popped or popped halfway and these are often caused by the various faults of a kernel.
If the hull has even the tinniest crack, the steam will leak out from it and prevent the starch from being completely gelatinized. This then cause the kernel to not puff out the starch, leaving us with a rock hard kernel.
Another reason could be that there may not be enough heat in the endosperm for the kernel to create a completely pressurized environment, again resulting in an ungelatinized starch.
Improper heating could also result in faulty popcorns. Heat that is too slow or have significantly low temperatures may not be enough to create pressure in the kernel. Heat that is uneven can cause the hull of the kernel to rupture before the kernel can build up enough pressure to pop. Hence, it is best to pop corns in dry heat produced by air or oil, especially the type that surrounds the kernel and heats it evenly, quickly and at the right temperature.
We hope this satisfies your curiosity and gives an idea of how to make the perfect popcorn! Feel free to ask us anything in the comments section or just send us a message!💕
Enjoy your popcorns!😉
References:
Comments