Salty, buttery, caramel, spicy, cheesy, or just plain, stove popped or microwaved, popcorn is a (sometimes) nutritious snack that has accompanied us to the cinema or at home on rainy nights with movies and blankets on the sofa. What makes this tasty snack so explosive? Let’s take a look.
What makes corn pop?
The most important thing for popcorn lovers to know is that although all popcorn is corn, not all corn is popcorn*. That means, for the seed to pop, it must have one important trait – a very hard pericarp (the outer layer that usually remains between the teeth after a popcorn binge). This hard hull holds the water contained inside the kernel, generating so much pressure that heat causes it to explode (instead of simply evaporating, as happens with other types of corn). The most common varieties with this propensity to explode are Zea mays everata and pisingallo.
On to the anatomy
Corn is composed of three parts: the pericarp (hull), the endosperm (starchy center), and the germ (the kernel of the seed). The outer hull consists mainly of cellulose, and although yellow is the most recognizable, it can also be red, black, or white. It is in the endosperm where the magic happens, as it is those starch granules that contain the water that, when heated, explodes the outer layer and turns the endosperm into that crunchy white foam that keeps us munching for hours.
Finally, some fun facts
In Mexico, corn was first cultivated 9,000 years ago and archaeologists have discovered remains of popcorn dating back to around 3600 BC that were prepared in hot clay pots or in ashes at high temperatures.
It has been documented in Chile that the indigenous populations made flour from ground popcorn. By adding water and sugar, they created a drink that could be consumed either hot or cold.
It was not until the Great Depression in the United States that the custom of eating popcorn as a snack at the movies was implemented, as its low cost made it an affordable luxury for struggling families. Since then the habit has gladly taken root in cinemas all over the world.
*Don’t fall for the logical fallacy that all corn is popcorn and end up putting your esquites or corn on the cob in the microwave hoping to get popcorn.