The most amazing and noticeable thing about Popcorn is how it explodes (expands).
If a popping expansion is 30-1 it means one cup of unpopped maize (kernels) will
pop
into 30 cups.
The best expansion available today is 45-1. Large kernels themselves decrease as
the kernel grows larger. Small round short kernels expand the most because of
the high
percentage of hard starch which is the material that actually explodes.
Each
kernel of popcorn contains a drop of water stored inside a circle of
soft starch. (That's why popcorn needs to contain 13.5 percent to 14
percent moisture.) The soft starch is surrounded by the kernel's
hard outer surface. As the kernel heats up, the water begins to
expand, and pressure builds against the hard starch. Eventually,
this hard surface gives way, causing the popcorn to "explode". As
the popcorn explodes, the soft starch inside the popcorn becomes
inflated and bursts, turning the kernel inside out. The steam inside
the kernel is released, and the popcorn is popped!
Popcorn
must have a hull in order to pop. There are varieties that
have a less noticeable hull after it has been popped. But, there are
no varieties that are completely "hull-less". Some white popcorn will
have less noticeable hulls.
There are mainly two different colors of popping corn yellow and
white, the yellow popcorn pops larger but the white popcorn is
generally a better flavor and more tender.
Without
moisture your popcorn can't pop. If left uncovered you can lose 1%
moisture on a hot day. This doesn't sound like much but if you lose
3% your popcorn will be "unpoppable". You should always store your
popcorn in an airtight container - glass or plastic - to avoid
losing moisture. Store it in a cool, dry
place such as a kitchen cabinet. Avoid the refrigerator. Most
refrigerators contain little moisture and can dry out the kernels.
There are two types of popcorn kernels - "butterfly" and
"mushroom". The "butterfly" popcorn kernel is usually large, light,
and fluffy, and it looks like it has wings, much like a butterfly. Its
tenderness depends on the size of kernel. The "mushroom" type of
kernel is more dense and compact, like a ball. It is used for candy
coating, caramelizing, etc. It does not have "wings" that would break
off during handling or cooking processes.