polenta, grits, masa harina.
Quite simply, cornmeal refers to any ground, dried corn. It's made not from our much-loved sweet corn, but from a very starchy variety, called field corn. Cornmeal may be white or yellow, depending on the type of corn used. With just slight differences in flavor, the two may be used interchangeably.
The most important distinction for cornmeal is whether it's whole-grain or degerminated. Like wheat and other grains, corn kernels consist of three parts: the oil-rich and vitamin-packed germ; the fibrous hull; and the starchy endosperm. Whole-grain cornmeal contains parts of all three and thus boasts a fuller, richer taste and twice the nutritional value of degerminated cornmeal. But because the germ is high in oil, whole-grain cornmeal turns rancid quickly.
Cornmeal also varies by grind—fine, medium, and coarse—although product labels don't always make this distinction. Medium- and fine-grain meals are most often used in baking, because they produce a lighter texture. The coarsest grain is usually reserved for polenta.
Specialty varieties of cornmeal include blue cornmeal, made from blue varieties of corn; polenta, which refers to both the popular Italian dish of cornmeal mush as well as the coarse-ground cornmeal used to make it; grits, a very coarse-ground cornmeal that can be made from white or yellow corn or hominy (corn treated with lime); and masa harina, a fine cornmeal made from hominy and used as the staple flour in Latin American kitchens.
Keep all varieties of whole-grain cornmeal in the freezer or refrigerator to keep them from becoming rancid. Degerminated cornmeal can be stored in a covered container at room temperature.