Legend has it that popcorn was invented by Native Americans, who took old maize, dried in the late summer sun from the outside in and scorched over an open fire, giving settlers from Europe their first puffed cereal. Hundreds of years later, in the Depression era, an enterprising concessionist set up a popcorn card outside a movie theater. The cinema was cheap entertainment for the masses and, unlike live theater with its bright lights at the foot of the actors stage (footlights) made by forcing gas through lime and setting it aflame (limelight), the moving picture houses (movies) were often the only place to spend a hot summer afternoon out of the sun (and frequently with fans, later air conditioning, to keep the heat from clustered bodies from driving away potential patrons. Thus, the association between movies and popcorn and summer blockbusters was initially forged.
Decades later, an obsessive-compulsive agronomist set out to make the perfect popping corn. Charlie Bowman and Orville Redenbacker tested zillions of varieties of corn and came up with a hybrid that produced the perfect marketable* pop. By the late 1970’s Orville Redenbacher’s Popping Corn had developed a fad in the snack foods industry and a name-brandnd loyalty throughout the universe. By then, the answer to the Trivial Pursuit question was well known:
Q: What makes popcorn pop?
A: Water.
More specifically – and this is something I was expected to know as the manager of a theater concession stand – heating a popcorn variety of corn kernel excites the water molecules inside until they explode through the kernel’s hard outer skin, now called a husk. This requires not just a good variety of corn, but proper drying methods to make sure the outer skin hardens just enough but not too much, while leaving the interior with enough moisture to get excited by heat and then pop. The heating effect can be achieved over a flame, the way the early Native Americans did it (and modern campers and fireplace owners do in modern times) or with superheated air. The idea is to make the water inside the kernel heat. As it heats it will try to expand. As it tries to expand it will meet the resistance of the hard outer skin (being made harder by the drying effect of the heat) and the phenomenon of experimental gas laws which basically say that as the volume of a gas increases in a non-expanding space, that temperature of that gas will increase. So that sets up a vicious cycle: The kernel is being heated, so the water inside is trying to expand–but can’t so it’s heating up even more, and then the kernel is being heated even more from outside, making the water inside expand even more (increasing the pressure)–but it can’t so it’s heating up even more and thereby increasing its pressure until BOOM!
Well, okay, so we hear it as a pop. The water inside the kernel explodes outward, carrying with it the soft tender guts of the corn seed and flinging away the hard destroyed husk.
Even better, a really fluffy explosion comes from capitalizing on the well-known reaction between water and heated oil. When popped in a kettle or frying pan the heated water manages to crack the hard, fried-to-a-crisp, outer skin of a popcorn kernel and its first contact with the world beyond is hot oil.
BOOM! Naturally, the mixture of hot oil and hot water causes an explosion, better than the explosion of just the steam coming out of a kernel.
But it wasn’t until the late 1990’s that researchers finally figured out why some kernels (called “old maids” for some reason), don’t pop. Using a scanning electron microscope, they were able to analyze the surface of corn kernels and predict that those with tiny cracks on otherwise polished surfaces, would fail to pop. Those microscopic cracks were letting steam seep out of the kernel before the oil was hot enough to cause that delicious explosion.#
So, how to get the fluffiest (most explosive) popcorn, regardless of the brand of popping corn you buy?
- Store your kernels in a cool dry place. Too much moisture in storage can weaken the outer skin (or, worse, attract molds which will ruin that skin).
- Sacrifice a starter-kernel, then dump the rest of your batch in when the sacrificial kernel pops to tell you the temperature of your popping device is sufficient.
- If you can afford the extra calories, use the hot oil trick. Corn oil is good because, well, it tastes like corn. As with my woking efforts, I prefer oils that can sustain a higher heat without breaking down. That tends to mean oils with less flavor; I like almond oil best and movie theaters often use coconut oil. They used to use Palm oil until health addicts started noticing and calling media attention to the fact that palm oil is the least healthy oil available for cooking (or at least that’s how they spun it).
- If you consume large amounts of popcorn, consider storing your corn in the refrigerator (but not the freezer, as the expansion of water as if freezes will destroy the hard outer skin). The rationale is that the (relatively) colder water escaping the kernel will meet that hot oil and the cold-meets-hot reaction will combine with the water-meets-oil reaction to make an even bigger pop. [I, personally, am dubious of this bit of theory; I figure the water will break through the outer skin of the kernel when it has reached the right temperature and pressure, so chilling the kernels will just make the oil colder when you dump them in. Furthermore, condensation on the outside of a cold kernel will give you the oil-meets-water effect without actually popping the kernels; why bother?]
- Do not salt your oil when you’re heating it. Particularly with poppers that have a stirring device spinning on the bottom, the addition of salt to the oil will just make the stirrers go around grinding up the bottom of the popper, and who wants to eat that? Add salt to your main batch of kernels so it gets dumped in when the mass popping begins. The corn will pick up salt as it expands. You might find that you don’t need butter. Consider adding powdered ginger, onion, garlic, cinnamon, taco seasoning, et cetera with the kernels instead. [Be careful, a little goes a long way.] Add sugar and you’re making “kettle korn” instead.
- If you do like butter, clarify it (slowly simmer the water out) first. The better theaters use concentrated butterfat, while others use imitation butter flavoring. Margarine and the various “Spread” products are often “partially hydrogenated” oils – meaning they’re oil that’s been whipped up and water has been introduced. Melting margarine basically returns the product back to oil-and-water. If you really prefer the taste of your ‘breakfast spread’ consider applying it with a little atomizer/mist spray bottle. For that matter, melted butter (or butterfat) is applied nicely this way, as well. Drizzling a liquid onto a kernel tends to make it whither away where the liquid hits.
Lastly, if you REALLY like your popcorn, try it for breakfast. After all, it’s the original puffed cereal.
A) Pop your corn without seasonings or flavored oil
B) Dump the popped corn into a large or medium bowl.
C) Lightly shake the bowl
D) Transfer a small amount to a smaller bowl, using your fingers to grab small hands-full (and leave husks and old maids behind)
E) Drizzle honey over the popped corn in the smaller bowl
F) Pour a small amount of milk over the corn and honey (yes, the puffs will start to shrivel).
G) Consume with a spoon before everything shrivels away!
–G!
*There are also those who believe that was the worst thing to happen to popcorn. The fluffiest pop, they argue, is the least flavorful. There are popcorn connoisseurs who prefer more local varieties that get less market share but have more intense flavors. For those, you might not want any toppings at all!
#Critics on the miserly right were quick to ask “Is this what our government spends the taxpayers’ research dollars on!?” To which the researchers responded, “No, this is what Con-Agra spends its snack food profits on - making more profit.”