Particular varieties do play a role in quality, taste, and popping ability, but the ultimate secrets to success with this gourmet treat lie with the basics: growing, harvesting, and drying.
New hybrids take 10 to 15 years to be developed, but fortunately, many seed catalogs already offer a great selection. Personal preference and your climate play a part in choosing which ones to grow. If your growing season is short, opt for varieties that mature in less than 100 days; these include 'Early Pink', 'Robust', and 'White Snow Puff'.
Growing popcorn is similar to growing sweet corn. To get full, well-filled ears, plant blocks of four to six rows rather than individual long rows. Space plants tightly, too--about 6 inches apart. The more plants you have, the more pollen you'll create, which in turn will make more kernels. Each stalk is likely to produce at least an ear or two, with three on smaller and miniature varieties. Six to eight 8-inch ears will yield about 1 pound of popcorn.
Sow seed 1 inch deep after the last spring frost and when the soil has warmed. Before planting, give the soil a dose of extra nitrogen from composted manure, blood meal, feather meal, or fish meal.
In my Oregon climate (zone 8), spring can be wet and cool, and seeds may rot in wet soil. Seedlings won't, so we start seeds in 2-inch pots and grow them in the greenhouse until seedlings reach about 3 inches high. At transplanting time, we fertilize with 2 to 3 inches of aged rabbit manure and don't have to fertilize again. To prevent root or stalk rot, make sure your soil drains well. However, if your soil is particularly sandy, you may have to hill soil around the plants so they don't fall over as they mature.
If you grow sweet corn, separate the two kinds by distance (200 feet), time (sow four weeks apart), or maturity date (90-day variety versus 120-day variety). If the popcorn's pollen crosses with sweet corn, the sweet corn kernels will be tough and chewy.
For quality popcorn, harvest the ears after the husks have dried and turned an even tan color. The kernels should be glossy and hard, showing no dent marks if you try to pierce them with your thumbnail.
Be patient: the corn isn't ready to pop yet. Allow the kernels to dry on the ear. In freshly harvested corn, the moisture content in the ends is different from that of the center. Tom Elsen of the American Pop Corn Company notes, "If you shell the cob at that point and throw all the kernels together, you won't reach popping perfection." If the kernels are too moist, they will be tough and chewy when popped; too dry, and they may not pop at all.
Instead, store harvested cobs in a cool, dry area with good air circulation and out of reach of rodents. The cob can act as a natural wick, distributing moisture more evenly throughout the ear. Drying time can vary from several weeks to several months--a lot faster in dry Arizona, for example, than in humid Florida.
When the moisture content is around 14 percent, kernels are ready to pop. Commercial growers have sophisticated equipment to tell them when their corn is ready, but home gardeners can rely on the old-fashioned way: when the kernels come easily off the cob, they're ready. The final test, though, is to shell some corn, pop it, and see for yourself.
Once the kernels pass the pop test, it's time to shell the corn. You can roll the kernels from the cob by hand, pushing firmly with your thumb, but to prevent sore thumbs, wear a glove, buy a popcorn sheller, or make it a family affair--kids love this step.
Store shelled corn in an airtight glass or plastic container. The Popcorn Board says not to store it in the refrigerator because the kernels can dry out. And don't leave popcorn out, uncovered, on a hot day, when it could lose an entire percent of its moisture. That may not sound like much, but a loss of as little as 3 percent of moisture can render popcorn unpoppable.
Properly stored popcorn will maintain its popping quality for years. In fact, researchers have discovered grains of popcorn estimated to be a thousand years old in Peruvian tombs--and they still popped.
Kris Wetherbee grows 10 varaieties of popcorn on her 40-acre farm, Camelot, in the rolling hills of western Oregon.
Photography by National Gardening Association
As a consumer, you can choose from yellow or white kernels, with yellow being more available. But as a home gardener, your choices include colorful red, blue, black, and even multicolored varieties. And, as popcorn connoisseurs know, definite taste differences exist among them.
As its name suggests, popcorn is corn that actually pops, which it does only when cured correctly. Popcorn's kernels consist of nearly all hard starch with a small amount of moisture (13 to 14 percent), covered by a thin, hard shell called the enamel. When perfectly cured popcorn is heated, each kernel acts as a miniature steam engine. As pressure builds and the moisture inside expands, the kernel explodes, inside out. All popcorn is a shade of white inside, so once popped, even the colored kinds look similar.
Yellow popcorn explodes into snowflake or butterfly shapes with a light corn taste. It also yields up to 46 times its original kernel size (white popcorn expands 35 to 40 times). This may explain why commercial vendors prefer yellow popcorn; each pound of popcorn produces more volume. Popular varieties include 'Giant Yellow' (105 days to maturity), 'Robust' (103 days), and 'South American' (103 days).
White popcorn bursts into smaller white mushroom shapes that are tender and slightly sweet. Try 'Japanese White Hulless' (110 days), 'White Cloud' (90 days), or 'White Snow Puff' (90 days).
Colored popcorn includes red, blue, black, and multicolored varieties. These pop into tender nuggets with a range of nutty flavors. While colored varieties are shades of white on the inside, their colored enamel shows specks of color amid the popped kernels. Red varieties include 'Early Pink' (85 days), which tastes similar to yellow popcorn; 'Ruby Red' (110 days); and 'Strawberry' (100 days), named for its small mahogany-colored cobs that look like strawberries. The last colors you might think of for corn may be blue or black, but 'Shaman's Blue' (112 days) is a striking purplish blue, and 'Black' (80 days) pops to bright white with black accents and a crunchy texture. Multicolored varieties include 'Calico' (90 days), 'Carousel' (104 days), and 'Park's Color Corn Mix' (95 days).
Miniature popcorn yields 2- to 4-inch cobs, compared to the 6- to 8-inch lengths of regular-size varieties. Kernels and popped corn are similarly small and have a slightly nutty taste. Varieties include 'Miniature Blue', 'Miniature Pink', and 'Multicolored Miniature', all needing 100 days to maturity.
Each year Americans consume nearly 18 billion quarts of popped corn. Plain, buttered, seasoned with spices or cheese, rolled into sweetened balls, and even coated with caramel and nuts, it's become one of this country's favorite snacks.
Corn of various types was first cultivated in Mexico, and popcorn was probably the first type grown. In fact, ears of popcorn, some estimated to date back 5,600 years, were found 50 years ago in a bat cave in New Mexico.
Yet in this country, popcorn didn't necessarily start off with a bang. Native Americans are credited with introducing popcorn to the colonists in the 1600s, but the real awakening came at the Chicago World's Fair in 1893, when Frederick Rueckheim presented a tasty popcorn confection, which he marketed six years later as Cracker Jack. By 1914, the American Pop Corn Company began selling the first brand-name popcorn, Jolly Time.