From Fine Cooking #112, pp. 32-33
by David Joachim and Andrew Schloss
It's corn season again, and for a short time, those gorgeous ears will be everywhere you look, from supermarkets to farmers' markets. Knowing that the season won't last long, smart cooks are taking advantage of the harvest, using corn in everything from soups and salads to side dishes and desserts (corn milk ice cream, anyone?).
Here's the lowdown on how to make the most of this once-a-year gem. The secret? Knowing the science behind what's happening in those kernels.
What should I look for when buying corn on the cob?
First, never buy already-husked corn; the husk helps protect the kernels and keep them moist. The husk should be bright green, moist, and fit snugly around the ear. The silks should appear moist (but not soggy) and pale in color. Pick the corn up-it should feel plump and somewhat heavy. Peel back the husk just a bit and look for tightly packed kernels with a few undeveloped kernels at the top of the cob. This is a sign of slightly immature corn, which is desirable, since young corn tastes the sweetest.
Are there different varieties of corn?
Yes. There are two main varieties: sweet corn and high-sugar hybrids. Sweet corn contains about 16 percent sugar and 23 percent polysaccharides (long-chain carbohydrates that give sweet corn a creamy texture). High-sugar hybrids contain more sugar-about 40 percent-and only 5 percent creamy polysaccharides. These supersweet hybrids were developed in the 1960s to help fresh corn stay sweet over long storage periods, and now account for most of the fresh corn sold in supermarkets. But corn connoisseurs tend to prefer the more complex taste and silky texture of traditional sweet corn. To check which variety you have in your hand, pierce a kernel with your fingertip; a milky liquid indicates traditional sweet corn, while a thin, watery liquid indicates a high-sugar hybrid.
How should I store freshly picked corn?
Sweet corn tastes best picked from the stalk and rushed to the pot. The minute it's harvested, enzymes inside the kernels cause the corn's sweet sugars to convert into less-sweet compounds. In only three days, corn can lose nearly half its sweetness and go from sublime to subpar. To minimize that sugar loss, you need to slow down enzyme activity. That means keeping corn at cold temperatures from the get-go. Choose ears that are freshly picked, preferably in the cool morning hours, and kept cold at the market. As soon as you can, get the corn into the coldest part of your refrigerator. Like other produce, corn contains mostly water and eventually dries when left in the open air. To keep it juicy, leave the husks on and wrap the corn tightly in plastic. If the husks look dry, wrap a wet paper towel around the base of the ears; better yet, stand the ears upright in an inch or two of water in the refrigerator and cover with plastic bags.
What's the best way to cook corn?
Briefly. Our favorite methods are grilled in the husk (which takes about 15 minutes over a hot grill fire) or husked and boiled in water just long enough to soften the outer skin of each kernel (1 to 3 minutes). Longer cooking makes for bland, starchy-tasting corn, because heat hastens the conversion of corn sugar to tasteless complex carbohydrates. If your corn shows signs of age or long storage (dry husks, mushy brown silks, shrunken kernels), you can boost its sweetness by adding about 1/2 cup sugar or 1⁄3 cup honey per gallon of boiling water. (Alternatively, add a little sugar or honey to the butter or other seasonings at the table). But avoid salting corn until after cooking-some evidence shows that salt toughens the outer skin of the kernels and keeps them from softening during cooking.