WHAT IS POPCORN?
There are six types of corn: sweetcorn, popcorn, flour corn, dent corn, flint corn and pod corn. The four most common types of corn are sweet, dent, flint, and popcorn.
Popcorn is grown in a field and looks very similar to a sweetcorn corn-on-the-cob. Popcorn is a whole grain. It is made up of three components: the germ, endosperm and pericarp (or known as the hull).
Popcorn differs from other types of corn in that its hull has just the right thickness to allow it to (eventually) burst open. Each kernel of popcorn contains a small drop of water stored inside a circle of soft starch. Popcorn needs between 13.5-14% moisture to pop. The soft starch is surrounded by the kernel’s hard outer surface.
WHAT MAKES POPCORN POP?
Popcorn will pop when the kernel is heated and the water begins to expand. At around 212 degrees the water will begin to turn into steam and encourage the starch inside each kernel to change into a superheated gelatinous substance. The kernel will continue to heat to around 347 degrees, the pressure inside the kernel will reach about 135 per square inch before finally bursting open.
As it explodes the steam inside the kernel is released, the soft starch inside the popcorn becomes inflated and spills out, cooling immediately and forming into the odd shape we know and love. A single kernel can swell to around 40-50 times its original size! The first part of starch that emerges forms a “leg” of sorts, which catapults the kernel like as the remaining starch spills out. This is why popcorn jumps as it cooks.
Here is a video of us making popcorn in the woods ourselves.