THE COLOMBIAN EXCHANGE: CORN
Of all the foods that Columbus and his peripatetic descendants brought from the New World to the Old—the turkey, potato, peanut, tomato, and tobacco, among many—none since has been more widely planted globally than maize (Zea mays), what we call corn.
It remains the most important grain consumed by humans in Latin America (and also in Africa), and the second most consumed on earth. But oddly, of the three global grain crops to include rice and wheat, it is the only one not grown primarily for direct human consumption. Humans eat a mere one-fifth of all maize grown globally; their animals eat two-thirds of it; and one-tenth is used in the manufacture of, broadly, other food and fuel. Most of the backbone of our overall North American diet, meat and dairy, is more properly viewed as converted corn.
Because it is highly mutable, genetically diverse, and culturally adaptable, no grain grows in more varying places on earth: parched and rainy, high and low in altitude, or cool and warm.
While Zea mays originated as a wild grass in Mexico, “98 percent of all the corn consumed in Mexico today comes from the U.S. A.,” says Rafael Mier, founder of Fundación Tortilla de Máiz Mexicana which promotes the growing and eating of indigenous Mexican maize. (Mexicans eat more than 200 pounds of corn per person per year, largely as tortillas; North Americans consume even more but, again, indirectly.)
Unlike the potato or tomato, maize met little resistance when introduced to Europe in the 1500s and today it’s widely used there in recipes, although less popularly in the United Kingdom and France where the word “corn” is both a synonym for any grain (U.K.) and, as a food, as livestock fodder.
A French friend of my father’s from dental school brought back white corn seed to his backyard in Paris so that he and his family could enjoy the sweet corn that he had fallen in love with while living here in the 1940s. He was either envied or derided by his neighbors, never both.
Maize is more nutritious when combined with other foods (note the famed Mesoamerican trinity of corn, squash, and beans) or when its hull is removed in the process of nixtamalization (most “hominy” or pozole or masa harina, hence many though not all corn tortillas and chips).
As for cooking with corn, well, variations are as legion as its placement all over the globe. However, we in North America often misunderstand or even mistreat the corn that we cook.
I always am dismayed when I see the trash can next to the fresh corn bin at the grocery store, as it encourages shoppers to peel back some husk to examine the cob, thereby ruining the ear for any subsequent buyer. It’s an unnecessary American fetish, that.
Gauge freshness by looking at the base where it was cut or torn from the stalk. That dries, shrinks or discolors as the days pass from harvest. Or see if the silks are slimy and black-brown; they, too, spoil with time. Or simply feel up near the top to see if the desired kernels have grown that far and are firm, tightly-packed and plump. No one need do a Missouri-ish strip to see if they’re there.
Some recipes stipulate that you use “the sharpest knife possible” when cutting the kernels from the cob for, say, a corn relish. OK, but be careful not to cut away at the cob itself which is roughage the relish won’t like. I use a regular table knife and get more of the milk that way, too.
Southern cooks have it correct when they wash their grits (or any coarse-cut cornmeal) before cooking; the close-to-indigestible chaff floats to the top of the water and can be skimmed off before cooking.
RECIPE: Oven Polenta with Roasted Mushrooms and Thyme
From bonappetit.com; serves 4. Bill St. John note: When Bon Appetit refers to “polenta” in the list of ingredients, it uses the Italian word to collapse both the preparation and its main ingredient, cornmeal. But not just any cornmeal, one that is medium- or coarse-ground. Don’t use fine-ground or corn flour; they’ll just make paste, not porridge. You’ll find some cornmeal for sale called “polenta” and, of course, it’s perfect.
Ingredients
1 1⁄2 pounds mixed mushrooms (such as crimini, shiitake, oyster, and/or maitake), torn into 1-inch pieces
4 sprigs thyme, plus leaves for serving
6 garlic cloves, smashed
Kosher salt, freshly ground pepper
1⁄4 cup extra-virgin olive oil
2 tablespoons unsalted butter
1 cup polenta
4 ounces Parmigiano-Reggiano cheese finely grated, plus more for serving
1 tablespoon red wine vinegar
Flaky sea salt
Directions
Place racks in upper and lower thirds of oven; preheat to 325 degrees. Combine mushrooms, thyme sprigs, and garlic on a large-rimmed baking sheet. Season generously with kosher salt and pepper; drizzle with oil. Toss to coat mushrooms, then spread out in an even layer. (Make sure not to crowd the mushrooms on the baking sheet; otherwise, they’ll steam instead of getting crispy.) Transfer to upper rack in oven and let mushrooms roast while you prepare polenta.
Bring 4 1⁄2 cups water to a simmer in a large ovenproof saucepan over medium-high heat. Add butter and a generous pinch of kosher salt and whisk to melt butter. Gradually add polenta, whisking constantly. (Gradually incorporating the polenta into the water is key to preventing clumps.) Return mixture to a boil, immediately cover pot, and transfer to lower rack in oven. Bake polenta, shaking baking sheet with mushrooms occasionally, until polenta is tender, 25–30 minutes.
Remove polenta from oven. Crank up oven temperature as high as it will go (but don’t broil). Continue to cook mushrooms until crisp around the edges, 5–10 minutes longer.
Meanwhile, carefully uncover polenta and whisk vigorously, scraping bottom of pan, until polenta is smooth and thick. Gradually add the cheese, whisking constantly until melted and incorporated; taste and season with more kosher salt and pepper. Cover and keep warm over low heat while mushrooms finish roasting. Remove mushrooms from oven; drizzle with vinegar. Toss to coat; let cool slightly.
Divide polenta among bowls and top with mushrooms, thyme leaves, sea salt, and more cheese.