Popcorn

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There’s been a lot of attention paid to the movies this past week due to the various awards handed out between old clips of previous awards being handed out that aired on TV Sunday night.

Which got me thinking about the food that has become synonymous with the movies: popcorn.

Native Americans enjoyed popcorn for millennia before movies came along: bits of popcorn found in a New Mexico cave have been carbon dated to about 4,000 years ago. (Of course, somebody could have been performing a shadow play on the wall of the cave via firelight while people munched, but there’s no scientific evidence for that.)

Corn kernels have three main parts: the pericarp (the outer bran layer, the stuff that gets caught in your teeth), the starchy endosperm, and the germ, which is what, in those lucky kernels that don’t get eaten by movie-watchers or other popcorn predators, turns into a new corn plant.

Popcorn pops because the pericarp is strong enough to hold in the steam created when the endosperm, which is 14.5 percent water, is heated—strong enough, that is, until the steam reaches 177 degrees C. and the pressure builds to 9.5 kilograms per square centimeter. At that point, the pericarp fails suddenly, and the endosperm explodes.

A good strong pericarp, then, is the key to a satisfactory pop. If the pericarp fails too soon, the steam escapes and the pressure never builds to the point where the endosperm can properly explode.

Just three or four years ago, food scientist Agung Tandjung at Purdue University in Indiana finally discovered why these pericarps pop open prematurely.

Tandjung found that, in the few seconds before the pericarp’s cellulose matrix is destroyed by the popping kernel, the heat actually changes its structure, making it momentarily stronger. Pericarps in which this occurs most effectively last longer, and then explode more violently, producing a bigger, fluffier morsel of popcorn.

With that knowledge in hand, popcorn breeders have begun breeding for that trait in their popcorn pericarps, poised, potentially, to produce pleasing, pleasurable (probably profitable!) perfect-popping popcorn.

Perhaps.

That discovery is a few years old, but just a couple of weeks ago new popcorn research appeared, this time not focused on a question even more vexing than the cause of unpopped kernels: are moviegoers being gouged when they pay big bucks for popcorn?

Wesley Hartmann, assistant professor of marketing at the Stanford Graduate School of Business, and Ricard Gil, assistant professor in economics at the University of California, Santa Cruz, decided to find out: and discovered that high-priced concessions actually benefit movie-goers by allowing theatres to keep ticket prices lower.

Movie houses only make about 20 percent of their gross revenues from concessions, but concessions provide 40 percent of their profitss. That’s because all of the money from concessions goes to the movie theatre, but the ticket revenue has to be shared with the movie’s distributors.

Hartmann and Gil compared concession sales in weeks with low and high movie attendance, and found that concession sales were proportionately higher during low-attendance periods. That suggests that people who will spend money on less-popular movies—the “die-hard” moviegoers—are also more likely to buy popcorn than the people who come out in larger numbers for the most popular movies.

If you raised ticket prices, the die-hard moviegoers would still come, though they might not buy as much popcorn. But the higher prices would drive away some of those who only come once in a while. By making concession prices high, movie theatres are making as much money as possible from the people who are most willing to pay, while drawing in so many of those who buy fewer concessions that they make up in numbers what they lack in gluttony.

As rarely as I get to the movies these days, it’s a good thing for movie theatres that those die-hard popcorn-chomping I’ll-watch-anything moviegoers are out there, picking up my slack, and thereby keeping ticket prices down.

I salute you, whoever you are.

It’s for your sake more than my own I hope the perfect-popping popcorn promise is someday fulfilled.

Permanent link to this article: https://edwardwillett.com/2008/02/popcorn/

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