Popcorn

• 1. Introduction

  ›

  Popcorn kernels can swell to 20 to 50 times their original size when heated. The word covers both a special variety of corn and the snack that comes out of it. Evidence of popcorn reaches back thousands of years in the Americas, which makes it one of the oldest snacks there is. People eat it salted, buttered, sweetened, or with artificial flavorings. This documentary starts inside a single kernel and works outward. What forces make a hard little seed burst into a crisp white puff? Who first noticed the trick, and where? How did a Chicago candy store owner and a Midwestern theater owner turn a hand-popped treat into a business? And why does the smell of popcorn pull people in so strongly?

  25635

• 2. Inside The Kernel

  ›

  Inside a popcorn kernel, 14-20% of the starchy endosperm is moisture, sealed behind a strong hull. Unlike most other grains, the hull is impervious to moisture. The starch inside is almost entirely a hard type, and the kernel also holds oil.

  Heat the kernel and the oil and water turn to steam. The starch gelatinizes and softens while the pressure climbs. The hull finally gives way at about 135 psi and a temperature of 356 F.

  The rupture drops the pressure inside at once, and the steam rushes outward. That expansion stretches the starch and proteins of the endosperm into an airy foam. As the foam cools, the starch and protein polymers set into the familiar crispy puff.

  Timing matters enormously. Heat a kernel too quickly and the steam in its outer layers can burst the hull before the starch at the center has fully gelatinized. The result is a partly popped kernel with a hard center.

  Heat it too slowly and the kernel may not pop at all. The tip where it once attached to the cob is not entirely moisture-proof, so steam can leak out fast enough to keep the pressure from ever reaching the breaking point. That leaky tip is one reason moisture, rather than heat alone, becomes the number growers watch.

  6336261

• 3. Quality And Flakes

  ›

  Growers aim for a moisture level of roughly 14-15% by weight, though the ideal shifts with variety and conditions. Freshly harvested popcorn will pop, but poorly, with weak expansion and chewy pieces. Wet kernels are also prone to mold in storage. Dry them too far, however, and the share of kernels that pop declines. Old popcorn drifts in the same direction as it dries out.

  Some kernels stay whole even after a batch has finished popping. The industry calls them "old maids." They lack enough moisture to make the steam needed for an explosion, and re-hydrating them before popping usually clears the problem.

  Producers and sellers judge popcorn on two measures: what percentage of kernels pop, and how much each one expands. Bigger pieces tend to be more tender, and shoppers associate them with higher quality. Expansion is also tied closely to profit. Theaters, for example, buy popcorn by weight and sell it by volume, so higher expansion earns more per unit of weight.

  In the trade, a popped kernel is called a "flake." Two shapes matter commercially. "Butterfly" flakes, also called "snowflake," are irregular with several protruding wings, and they are prized for tenderness and less noticeable hulls. "Mushroom" flakes are mostly ball-shaped with few wings. They are less fragile, so packaged popcorn and caramel corn often use them.

  A single cob can yield both shapes. Hybrids that give 100% butterfly flakes or 100% mushroom flakes exist, and the mushroom hybrid arrived only in 1998.

  Kernels themselves come in "rice" type, long and pointed at both ends, and "pearl" type, rounded at the top. Commercial production has moved mostly to pearl. Colors now include white, yellow, black, red, mauve, purple, and variegated, yet popped corn is always off-yellow or white because only the hull is colored. Mauve and purple popcorn usually have smaller, nutty kernels.

  6162659

• 4. Ancient Origins

  ›

  Corn was domesticated about 9,000 years ago in the Balsas River Valley of Central Mexico. Popping came along early, and archaeologists have traced it through several sites.

  On the northern coast of Peru, macrofossil cobs found at the Paredones and Huaca Prieta sites between 2007 and 2011 showed evidence of popping corn as early as 4,700 BCE. Other fossil evidence suggests corn was present in Peru by the same date and was being popped there over 1,000 years ago. Farmers in the Amazon basin were already cultivating corn 6,000 years ago.

  In 1948 and 1950, two Harvard graduate students made a find in west-central New Mexico. Herbert W. Dick, in anthropology, and Claude Earle Smith, Junior, in botany, worked in a complex of rock shelters in Catron County that they dubbed the "Bat Cave." There they recovered ears of popcorn dated as early as 3600 BCE. The remains are attributed to the Ancestral Puebloan peoples, who kept trade networks with peoples in tropical Mexico.

  Through the 19th century, cooks popped kernels by hand on stove tops over flame. Sellers on the East Coast of the United States marketed the kernels under names such as Pearls or Nonpareil. The term popped corn first appeared in John Russell Bartlett's 1848 Dictionary of Americanisms. Even Cracker Jack was popped by hand in its early years.

  314131518

• 5. Steam And Showmanship

  ›

  Charles Cretors, a Chicago candy store owner, had already built a number of steam-powered machines for roasting nuts when he turned the technology on corn. His popcorn machine was invented in Chicago in 1885, and he introduced it at the Columbian Exposition in 1893. It was the first patented steam-driven machine to pop corn in oil.

  Before it, vendors held a wire basket over an open flame. At best, the corn came out hot, dry, and unevenly cooked. Cretors popped his in a blend of one-third clarified butter, two-thirds lard, and salt. That mixture withstands the 450 F needed to pop corn and gives off little smoke.

  The machine was also a piece of street theater. A fire under a boiler made steam that drove a small engine, which turned gears, a shaft, and an agitator that stirred the corn. The same power moved a small puppet called "The Toasty Roasty Man," there to catch the eye of passersby. Excess steam blew a small, shrill whistle for the same purpose.

  A wire running to the top of the cooking pan let the operator disengage the drive, lift the cover, and dump the popped corn into a bin below. Exhaust from the engine was piped to a pan under that bin and kept the fresh popcorn warm. By the turn of the century, Cretors had put steam-powered popcorn makers on street carts. Another method survives alongside, the "popcorn hammer," a large cast-iron canister with a heavy lid, turned slowly over a fire like a rotisserie.

  At the same 1893 fair, F. W. Rueckheim introduced a molasses-flavored "Candied Popcorn," the first caramel corn. His brother Louis slightly altered the recipe and sold it as Cracker Jack in 1896.

  4038253248

• 6. Theaters And Hard Times

  ›

  During the Great Depression, a bag of popcorn cost 5-10 cents, and people bought it. While other businesses failed, the popcorn business thrived and gave an income to many struggling farmers and entrepreneurs. Among them was the Redenbacher family, namesake of the Orville Redenbacher's brand.

  World War II brought another boost. Sugar rations diminished candy production, and Americans made up for it by eating three times as much popcorn as before.

  Theater owners did not welcome the snack at first. Many thought it distracted from the films. In 1938, a Midwestern theater owner named Glen W. Dickinson Sr. installed popcorn machines in the lobbies of his Dickinson theaters. Popcorn proved more profitable than tickets. On the suggestion of his production consultant, R. Ray Aden, Dickinson bought popcorn farms, which let him keep ticket prices down. The venture worked, and popcorn soon spread to other theaters.

  Television in the 1940s cut popcorn sales as theater attendance fell. The Popcorn Institute, a trade association of popcorn processors, promoted eating it at home and brought consumption back to its earlier levels.

  Orville Redenbacher's namesake brand launched in 1970. In 1981, General Mills received the first patent for a microwave oven popcorn bag, and consumption rose again.

  At least six localities in the Midwestern United States claim to be the "Popcorn Capital of the World": Ridgway, Illinois; Valparaiso, Indiana; Van Buren, Indiana; Schaller, Iowa; Marion, Ohio; and North Loup, Nebraska. According to the USDA, popcorn is grown mostly in Nebraska and Indiana, and increasingly in Texas. Illinois, for its part, made popcorn its official state snack food after an elementary school project.

  4849503436

• 7. Taste And Aroma

  ›

  Film historian Stuart Hanson of De Montfort University in Leicester once offered a blunt verdict on cinema prices. He said, "One of the great jokes in the industry is that popcorn is second only to cocaine or heroin in terms of profit." Cinemas have come under fire for their high markup, yet the snack remains a fixture at sporting events and movie theaters.

  Tastes differ by country. In the United States, popcorn is mostly a hearty, salted snack. In Germany, the sweet version with caramelized sugar predominates.

  The smell has an unusually attractive pull on people. Popcorn contains high levels of two powerful aroma compounds, 6-acetyl-2,3,4,5-tetrahydropyridine and 2-acetyl-1-pyrroline. Food and other industries also use these compounds to make products smell like popcorn, bread, or other foods that carry them naturally.

  In the 1800s, Americans ate popcorn as a breakfast cereal, usually with milk and a sweetener. Popcorn balls, kernels stuck together with a sugary "glue," were hugely popular around the turn of the 20th century. Their popularity has waned, though some places still serve them as a Halloween treat.

  Cracker Jack today is commercially produced candy of peanuts mixed with caramel-covered popcorn. Kettle corn, cooked with white sugar and salt in a large copper kettle, was once reserved for specialty shops and county fairs. It has recently caught on, especially in the microwave market. The home popcorn maker is a relatively new appliance, and it lets cooks pick their own flavors and healthier styles.

  In India, popped sorghum is a popular snack. It resembles popcorn, but the puffs are smaller. Sorghum grains contain phenolic acids, and most contain flavonoids, being among the highest food sources of the flavonoid proanthocyanidin.

  4647515253

• 8. Nutrition And Risks

  ›

  A 100 gram portion of air-popped popcorn, with no salt or additives, provides 382 calories. It is 4% water, 78% carbohydrates including 15% dietary fiber, 12% protein, and 4% fat. It is a rich source of riboflavin at 25% of the Daily Value. Manganese, phosphorus, and zinc each supply 36-45% of the Daily Value.

  Movie theater popcorn is a different matter. Theaters commonly pop the corn in coconut oil and top it with butter or margarine, so it carries large amounts of saturated fat and sodium.

  The American Academy of Pediatrics lists popcorn among foods not to serve to children under four, because of the choking risk.

  Microwave popcorn carries its own history. Its artificial-butter flavorant diacetyl, once common, has been implicated in respiratory illness among microwave popcorn factory workers, known as "popcorn lung." Major United States makers have stopped using it, including Orville Redenbacher's, Act II, Pop Secret, and Jolly Time.

  Popcorn also has uses beyond the bowl. Threaded onto a string, it decorates walls and Christmas trees in some parts of North America and on the Balkan peninsula. Some shipping companies have tried it as a biodegradable replacement for expanded polystyrene packing material. It attracts pests, burns easily, and costs more and is denser than polystyrene. A more processed expanded corn foam was developed to overcome those limits, and it forms starch-based foam peanuts.

  5154555660