This week’s question was asked by Jordyn Nance, eighth grade, Tomah Middle School.
Teacher: Manuela Coffey.
QUESTION: How did popcorn become a food associated with movie theaters?
ANSWER: A good question about our American culture, but there is some neat science concerning popcorn. Popcorn had a slow start in the movie theaters but now is a staple, a deemed necessity in the cinema.
Popcorn was first sold by street vendors at fairs and carnivals in the mid-1800s after the first steam-powered popper was created in 1885. Movie theaters, before the “talkies” in 1927, refused to sell popcorn because people had to be literate to read the writing on the screen, and theaters catered to a sophisticated, more literate audience, not us “great unwashed masses.” Theaters did not want to be associated with food that would be noisily chomped on and a strewn mess on the floor.
When talking movies came along, combined with the Great Depression, people wanted cheap entertainment. Early popcorn machines were set up on the sidewalks outside the theater, gradually moving to inside the door. During World War II, popcorn sales soared, as sugar for candies was rationed.
These days popcorn is a cash cow for theater operators. The concession stand is what keeps most movie theaters afloat, accounting for about 50 percent of the theater’s profit. The popcorn smell is quite enticing, especially when they throw on the butter.
Those theater people are no dummies. Popcorn is heavily salted, making you and me crave soft drinks. Those soft drinks have a high markup as well.
Now the neat science. Not all corns are created equal. Of the five different types of corn − dent, flint, pod, sweet and popcorn − only popcorn will pop consistently.
Popcorn kernels contain water, ideally a bit over 13 percent. The water is stored in a small circle of soft starch. Surrounding the soft starch is a very hard enamel-like starch. When the popcorn kernel is heated, the water inside heats up and starts to expand. The job of the hard starch is to resist the expanding water for as long as possible.
After some time, the water expands with such pressure that the hard starch gives way, the water bursts out, causing the popcorn kernel to explode. That soft starch pops out, and the kernel turns inside out. The water, converted into steam, is released and the corn kernel is popped.
Those other four varieties of corn can efficiently store water. But their outer starch is not hard enough to withstand the water pressure of the expanding kernel and so nothing pops.
Popcorn is actually a member of the grass family, and scientifically known as Zea mays everta, a type of maize. It is a whole grain. There are other grains that will “pop,” among them are sorghum, quinoa, millet, and amaranth. All these grains have a hard moisture-sealed hull and a dense starchy interior. Sorghum is popular in the South.
We have all experienced un-popped kernels remaining, referred to in the industry as “old maids.” These kernels did not pop because there was not enough moisture to create sufficient steam for an explosion.
Popcorn is quite nutritious, high in dietary fiber and antioxidants, free of sugar and salt and low in calories and fat. Popcorn is very good for a person, if it’s not overwhelmed with salt and butter or oleo. Cracker Jacks is caramel-covered popcorn with peanuts added.
Are Puffed Wheat and Puffed Rice the same as popcorn? They are similar. Those puffed grains are made by putting whole grains under high pressure with steam in a containment vessel. The vessel’s pressure is suddenly released, and the steam that was entrapped in the soft material (endosperm) of the kernel will flash and bloat, increasing its volume many times the original size.
January 19 is National Popcorn Day in the United States. Orville Redenbacher made quite a name for himself in the popcorn business. Born on a farm in Brazil, Indiana, in 1907, Redenbacher played in the high school band, graduated from Purdue University where he was a track star, was a county agriculture agent, outlived two wives and had captured a third of the popcorn business by 1970. On Sept. 4, 2012, Valparaiso, Indiana, unveiled a statue of Redenbacher at the city’s annual popcorn festival.
Send questions and comments to: firstname.lastname@example.org.
Larry Scheckel is a retired Tomah High School physics teacher.
If your question appears in this column, you will receive a free Value Meal from McDonald’s and a coupon from Pizza Hut.