Food is delicious, not to mention kind of important.
But food also goes bad, so humans have invented many ways to preserve it to eat later or far
from where it was harvested.
Unfortunately, some of these methods require unhealthy chemicals or degrade the food's
nutritional value.
Luckily, freezing can preserve food with most of its nutrients, well, frozen in place!
The important part is that most chemical and biological processes run slower at lower temperatures,
which means that if you cool food a lot, enzymes and bacteria and fungi in the food get too
cold to decompose it.
That's why food lasts longer in the freezer than in the fridge than on the counter.
Freezing, however, wasn't always an easy task, especially before fridges were invented.
It's not that freezing food is a new idea - I mean, people who live in cold places have
done it by default for thousands of years, but things got messy when we started creating
artificial winter to freeze food in warmer climates.
Early freezers were basically rooms full of salty ice, which, while they could freeze
food, took many hours or even days.
A slow freeze gives fluid within cells the time to stack up into big crystals.
Since water expands when it freezes, the sharp edges of these crystals poke holes through
the walls of the cells, and when the food thaws, the fluid leaks out.
Gross!
Even grosser?
Birds eyes.
Clarence Birdseye, to be precise.
An American entrepreneur who lived in Arctic Canada in the nineteen-teens, Birdseye noticed
that when Inuit people went ice fishing in minus 40 degree windy conditions, their catch
froze almost immediately.
When cooked later, the fish tasted fresh!
Birdseye realized that the arctic-frozen foods were tasty because they froze quickly and
formed smaller ice crystals that didn't damage the cells.
Inspired, Birdseye went on to develop a process to quickly freeze food by pressing small packages
between metal plates chilled to 40 below zero.
Combined with clever marketing, this allowed Birdseye to bring arctic winter to the rest
of the world and to almost singlehandedly jumpstart the modern market for frozen foods.
You probably even have your own freezer, a marvelous device cold enough to quick-freeze
almost any food you put in it.
In other words: the North Pole, in your kitchen.