Flint Corn

Flint corn is a group of maize varieties whose kernels have a hard, glassy outer layer of starch that surrounds a small soft core, giving it a smooth, rounded appearance without the dent seen in dent corn. The ears are generally small and slender, and the kernels come in a wide range of colors including white, yellow, red, blue, orange and multicolored forms sold as Indian or calico corn. The corn is hard and dense, tastes sweet and nutty and, once ground, produces coarse, flavorful meal. Flint types tolerate cold soils and mature early, and they resist mold and insects in storage. Common forms sold include whole dried ears, polenta meal, and flour.

Maize was domesticated in southern Mexico, from a wild grass called teosinte, around 9,000 years ago. Flint types were developed by Indigenous farmers in many parts of the Americas, and were the corn grown across northeastern North America, the Caribbean and the Andes by the time Europeans arrived. The word flint refers to the hard kernel. Maize comes from the Taíno word mahiz, which entered Spanish and then English. Zea is Greek for a kind of grain, and indurata means hardened in Latin.

Flint corn was among the crops carried by Native peoples across the Americas. In the northeastern United States, groups such as the Haudenosaunee grew flint varieties in the Three Sisters planting alongside beans and squash, and corn was also pounded into meal, made into hominy, and stored for the winter. The early English settlers learned to grow it, and the hardy, short-season crop saved colonists from hunger. Corn mush and johnnycake, made from flint cornmeal, became New England staples.

Columbus carried maize to Spain, and flint types were especially suited to the cooler climates of Europe, spreading across Italy, the Balkans, and Portugal, where they formed the basis of polenta and broa. The Italian polenta tradition, which once used other grains, later adopted corn, and varieties such as Otto File from Liguria are known for their quality.

Later in the twentieth century, dent corn replaced flint for industrial uses because it gave higher yields. Still, flint corn endures in heirloom and specialty varieties, with the multicolored Glass Gem corn gaining widespread popularity after about 2012 for its jewel-like appearance.

Flint corn is stone-ground into polenta, grits and cornmeal for porridges, cakes and breads, such as cornbread and johnnycake. Whole kernels are processed with an alkali, a method called nixtamalization, to make hominy, masa and tortillas. Some varieties are popped, as flint types like Calico corn make small, crisp popcorn. Colorful ears are used as autumn decorations. Corn is also used for animal feed and, in some places, for fermented drinks.

Whole-grain flint corn supplies complex carbohydrates, fiber, some protein, and carotenoids in yellow and orange types, along with anthocyanins in blue and red types. Traditional nixtamalization increases the availability of niacin, which prevents the deficiency disease pellagra, a problem historically in populations eating untreated corn as a main food. Corn is naturally gluten free. Stone-ground whole meal retains more of the germ and fiber than degermed products.