More than 500 billion pounds of corn are grown in the United States annually, mostly for livestock. Sadly, we humans have lost our appreciation for corn as a whole grain to cook and eat ourselves. Today, we think of corn mostly as a sweet vegetable, but many types of unsweet grain corn deserve much wider use in our gardens and kitchens.
Corn (Zea mays) was developed about 7,000 years ago in the Oaxaca Valley of Mexico. Many Native American tribes came to depend upon this easy-to-grow, protein-rich grain. Modern, commercial grain corn products are commonly degermed to lengthen their shelf life, but degerming removes flavor and nutrition. So, if you want to enjoy the most flavorful and nutritious corn possible, you have to do what the Oaxacans did — grow and grind your own.
Processed cornmeal, grits, polenta, and other corn products have had their skins and germs removed, both of which carry much of the flavor. The germ is removed because it’s high in natural fats, which turn rancid quickly after the corn is ground if it’s not refrigerated. Removing the germ from the corn dramatically reduces the vitamin and mineral content. This “Whole Grain is Healthier” table shows the dramatic nutritional difference between 1 cup of whole-grain yellow cornmeal and 1 cup of degermed yellow cornmeal.
And there’s another problem: Mass-market corn products, including most organic ones, are made from high-yield hybrids rather than from high-flavor corns. The optimal corns for people-food are heirlooms or specialty cultivars. Some small companies are producing exceptional freshly ground, whole-grain heirloom corn products.
The main reason companies grow hybrid corn rather than open-pollinated (OP) corn is productivity. Some hybrids are more productive, disease-tolerant, and resistant to falling over — called “lodging” — than OP varieties. But they don’t taste very good. And by saving the seeds from your own OP corn, you can develop a variety well-adapted to your climate, site, and soil. There may also be important nutritional differences between modern hybrids and many varieties of OP corn; for example, OP corn often has higher protein content than hybrids.
Whole Corn Cookery
If you start with a good-tasting cultivar, handle it properly, and cook it with care, whole-grain corn can be the basis for some truly satisfying food. Glenn Roberts, founder of Anson Mills in Columbia, South Carolina, speaks of heirloom corn the way vintners speak of wine. (Anson Mills sells cornmeal, polenta, and grits to top chefs and other consumers by mail order, and works to preserve 20 heirloom corns.) Roberts describes blue-corn grits as having “flavor nuances that start out mineral and then blossom into citrus peel” as they’re slowly cooked at temperatures of less than 180 degrees Fahrenheit. To get the full flavor from any type of culinary grain corn, Roberts says, it’s essential for the corn to ripen and dry on the stalks. Slow drying, low-temperature milling, and immediate refrigeration of freshly ground corn keep the flavors alive.
Because whole-grain cornmeal retains its natural oils, you may not need to add butter or other fats when baking with it. Grain-corn comfort foods include mush, also known as polenta, and spoon bread, which is warm mush mixed with eggs and milk and baked into a fluffy casserole. You can make grits from coarsely ground whole corn, too. Cooking times for whole-grain corn grits range from 20 minutes to more than an hour, depending on the cultivar and coarseness of the grind. If you’re pressed for time, try making a big batch and refrigerating the leftovers.
Parched corn offers yet another scrumptious way to eat grain corn. To parch corn, cook the kernels in a dry pan without oil or other fat, or in a microwave oven. In about 5 minutes at medium-low heat, the toasting kernels will start to swell and split, releasing a wonderful aroma. The best parching corns are slow to burn, though it’s important to keep them moving by stirring or shaking the pan. You also need to hold a lid or screen over the pan to keep the kernels from popping out. You can keep uncooked parching corn kernels indefinitely in an airtight container, or cook up batches and have them ready to munch in zip-close bags.
Growing Food Corn
In the centuries before Columbus arrived in the Americas, indigenous peoples from Alberta to Peru saved their most flavorful corns for seed. Many of these strains are extinct, but some of the flavors remain intact in Native American corn strains still grown in Mexico and the southwestern United States. These corns evolved in dry soil conditions, so they often grow poorly in cold or wet climates; unlike hybrid corn, most old OP varieties stop growing new roots as they mature, so root rot is a serious threat.
Here’s a run-down of the main types of grain corn, differentiated by kernel characteristics.
Flour corns have starchy endosperms (the central, fleshy part of each kernel), so they’re the best for grinding into fine cornmeal, often called corn flour. Most can be eaten fresh — roasted or boiled on the cob, but only for a day or two because sugars quickly convert to starch as the kernels mature. Some flour corns are good for parching too.
Flint corns, sometimes called hard corns, have a lot of “flinty” endosperm and only a little “flour” endosperm. Flints are the most flavorful corn for grinding into grits or polenta.
Dent corns have a central flour endosperm surrounded by a flinty endosperm. These shrink at different rates as kernels dry, causing a dent to form in the top of each kernel. Dents can be ground into flour, grits, and masa, and added to other foods, such as soups.
If you want to try growing your own grain corn, pick cultivars adapted to your climate. Start with a small plot of a single cultivar. Grain-corn pollen can cause sweet corn to go starchy, so it’s important to separate the two by at least 100 feet. And, because grain corn is wind-pollinated, it should be planted in blocks rather than single rows to get well-filled ears.
Before planting, boost soil fertility with compost or worm castings. You can plant corn after a nitrogen-fixing cover crop such as alfalfa, or spread a mulch of nitrogen-rich grass clippings. Wait until the soil is warm before planting untreated corn. A cold, wet seedbed can decrease seedling survival and encourage root rot.
The ideal spacing between plants varies by cultivar. A northern flint, which grows less than 8 feet tall, should do well spaced 8 inches apart; cultivars more than 8 feet tall will need 18 to 24 inches between plants. With the tall corns, lodging is a big concern, but open spacing is needed to provide enough light so the plants grow stiff and strong.
As the corn grows, use a hoe to control weeds while hilling up soil around the base of the plants. Never remove the side branches, called tillers. Some cultivars actually produce ears on the tillers, and tillers are often an important pollen source.
Hybrid corn usually sheds pollen all at once, but OP cultivars that form tillers have a longer pollination period involving both the primary tassel and tassels growing from tiller tips.
If strong winds knock your corn over when the ears are ripening, don’t worry. Give it a few days to stand back up on its own. If three days pass and the corn is still lying low, try tamping soil around the base of the plant with the heel of your shoe to provide extra support.
Dry weather is a big plus when the ears are drying, but if wet weather strikes and the ears aren't quite dry, go ahead and harvest and remove the husks. Dry them indoors, using a fan to help complete the drying process. In naturally dry climates, you can store your corn on the cob in a pest-proof place where temperatures are less than 55 degrees. In humid locales, it’s best to store the dried ears or shelled corn in airtight bins, cans, or pails. Never store damp corn, because the molds that form are toxic to people and animals. No matter where you live, check stored corn often for meal moths and weevils. If you find these pests, put your corn in a freezer for three or four days to kill them.
Growing your own corn gives you better-tasting and more nutritious cornmeal, and it’s an excellent, high-yielding crop for anyone who wants to be more self-sufficient. A small patch can be harvested easily by hand and stored for year-round use. You can also feed this protein-rich grain, along with the corn stalks, to your animals. Sheep will eat the leaves, and cows and goats will eat the leaves and stalks.
Barbara Pleasant is a veteran gardening journalist who grows a large food garden in Virginia.