how does popcorn pop

by cj

Jean Michel Jarre

Jean Michel Jarre

we figured out that theres water inside and told all the kids that

Barry's Response - The kernels hold both water and oil. The non-porous shell keeps them in for a long time.

When it gets hot and the water needs to boil, so-called superheated steam pushes out and at the same time the hull has been softening from the heat. Eventually it breaks. The whole thing explodes and freezes into the familiar styrofoam-like state, which cools and sets almost instantaneously.

For this, you need a certain type of corn. Not all corn (maize) pops in this manner when heated. The non-porous shell helps ensure this water-retention capability. The kernel has to keep the water locked in near the centre so that this tiny pool does not evaporate even when the rest of the kernel does, even after being left out in a dry environment for a long time.

Not only moisture, but oil as well. The oil collects heat to transfer to the water. A mantle-like layer of starch surrounds the water and becomes quite soft when heated,something like caramel. Meanwhile, the water inside becomes superheated and the pressure builds up from within.

While this happens, the starch mixture becomes even more soft and gooey, and finally the outer shell cracks under all this pressure. When this happens the whole thing blows up like thunder and the starch expands, depressurizes and cools, almost instantly. It becomes stiff just as fast and the popped kernel now retains its new shape. Voila!

Now you have it, cj.

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