Depending on where you reside, you could run right into a bag of “Grits and Polenta” in your supermarket. As a result of the marketing of certain brands and the now-corrected musings of a former Food Network personality, there may be the misperception that polenta and grits are principally the identical. They will not be.
Polenta is Latin for crushed and hulled barley and, per Merriam-Webster, is said to pollen, the Latin word for wonderful flour. Traditionally made with flint corn, polenta might be made with buckwheat flour, barley meal, yellow corn meal, or any mixture containing thereof. Grits, then again, is nearly at all times made with dent corn. Dent corn is a high-starch form of maize, named due to the dip or “dent” on the highest of the corn kernel (via SFGate). In keeping with Bon Appetit, the difference in corn primarily affects the dishes’ textures: polenta is chewier, while grits are smooth and creamy.
One other difference between polenta and grits is that the corn used for grits is often, but not at all times, nixtamalized (via The Congaree Milling Company). Nixtamalization is the applying of an alkali, like limewater, to corn. This makes the niacin within the corn kernel bioavailable, making the treated corn more nutritious. It partially breaks down the kernel’s hull, making the corn easier to grind, and removes just about all the mycotoxins the corn can have. This process also kills the germ, making the kernels secure to store long-term without the potential of sprouting (via Mexicanist). Finally, per Cooks Illustrated, the alkali softens the starch, reducing the needed cooking time by a 3rd or more. While polenta can take as much as 3 hours to cook, grits take not more than 45 minutes.