Cornmeal, Cornstarch, Corn Flour, they’re all made from that incredibly versatile and internationally esteemed New World grain called corn in the United States and maize, from the Caribbean Taino Indian word rnahiz, almost everywhere else.
A kernel of corn is a seed with essentially three parts. The tough, outer hull (the pericarp) is made mostly of indigestible cellulose. A body of starchy material (the endosperrn) nourishes the seed when it sprouts (germinates). The life-transmitting embryo (the germ) in the middle of the seed is the part that will grow into a new plant when conditions are right for germination. It contains the seed’s main energy supply in the form of oil.
Corn kernels can be processed in dozens of ways to produce an astounding variety of products. One main distinction hinges upon which parts of the kernels are retained. The starchy endosperm is always used, but the outer hull and/or the germ may or may not be removed. What is called cornstarch in the United States and corn flour in the United Kingdom is the dried and finely powdered endosperm alone.
Another main distinction among cornmeal products is the texture, that is, how coarsely or finely the dried kernels have been ground. But the names can be perplexing:
Flour, of course, is fine, not coarse,
While meal is much more coarse, of course.
The meal called “Medium,” of course,
Is coarse, but not as coarse as “Coarse.”
But if the label calls it “Fine,”
It’s flour, not meal, I would opine.
Historically, of course, dried corn kernels were pulverized between millstones in a water wheel powered mill down by the old mill stream. Stone-ground cornmeal, sometimes nostalgically but nonsensically called water-ground cornmeal, is available in many “health-food” stores. It is slightly more nutritious and flavorful than other cornmeals because it retains some of the hull or bran and some of the oil-containing germ. But because of the oil, it is perishable and cannot be stored at room temperature for very long without turning rancid. Refrigerated, it will keep for a couple of months.
Most modern cornmeal is produced by crushing the dried kernels between huge steel rollers, making grains that are more sharply shaped than in the stone-ground meals. The rolled product, referred to as steel-cut, contains only the starchy endosperm with very little hull or germ, and it therefore has a very long shelf life when kept in a cool, sealed container. If your supermarket’s cornmeal isn’t labeled stone-ground or water-ground, it’s steel-cut. (To split a hair, steelcut cornmeal isn’t cut; it’s steel-crushed.)
After the kernels’ hulls and germs are removed either mechanically or chemically with lime or lye, the endosperm can be washed and dried, at which time it is known as hominy. Then it may be ground or crushed into rather coarse particles to form hominy grits. After their water is restored by boiling, hominy grits can be found on virtually every breakfast plate below the Mason-Dixon Line.
Which product to use for what? Southerners insist that their traditional cornbread be made from stone-ground white cornmeal, either coarse or medium depending on individual preference. Yankees aren’t so fussy, and even go so far as to combine the cornmeal with wheat flour and sugar to make a more breadlike bread, because cornmeal doesn’t contain the gluten that gives bread its elastic texture.
Polenta is generally made with yellow cornmeal of either coarse or fine grind, because the boiled cornmeal softens into a homogeneous mass anyway. And need I point out that yellow cornmeal is made from yellow corn and white cornmeal is made from white corn?