Corn on the cob is best served hot immediately after it finishes cooking because it can become tough and lose flavor. There are several options you can use to keep the corn warm, depending on the amount of time until serving, the amount of corn you cook and the available equipment. Try the cooler method to keep a large batch of corn warm for several hours. For short term warming, a steam pot works well for boiled or steamed corn, while the oven method works well for oven or grill roasted corn.
Place the hot corn in a clean, insulated cooler. This method is common for large batches of corn, but you can use a smaller cooler, such as one designed to carry six beverages, to keep a smaller batch of corn warm.
Cover the corn with a large piece of aluminum foil; tuck the foil in around the edges to seal in the heat.
Place several clean towels in the cooler on top of the foil, using enough towels to fill the cooler to the top. Close the cooler tightly. The cooler walls, aluminum foil and towels act as insulation to keep the corn hot for several hours.
Place the corn on the cob in a baking dish or roasting pan large enough to hold all of the corn. Add just enough water to line the bottom of the pan. If the individual pieces of corn are wrapped in foil, leave them wrapped and omit the water in the bottom of the pan.
Cover the corn with aluminum foil; seal the foil tightly around the edges of the pan. The large foil wrapping isn't needed if the corn is individually wrapped.
Place the corn in an oven preheated to 200 degrees Fahrenheit or cooler for up to about 30 minutes. The water in the bottom of the pan, if applicable, steams around the corn to keep it moist, but too much time in the pan can overcook the corn.
Place the corn on the cob in a steamer basket.
Add 1 to 2 inches of hot water to the bottom of a steam pot and set the basket of corn inside the pot. A lid isn't necessary because the corn is already cooked; a lid traps in steam and can overcook the corn. If you leave the pot uncovered, steam can escape, but it still passes through the the pieces of corn to keep them warm.
Keep the corn on a stove burner set to simmer for about 30 minutes. This method uses steam to keep the corn warm.
Boiled corn can simply be left in the hot water for up to 10 minutes without loss of flavor or texture. Similarly, roasted corn wrapped in aluminum foil and microwaved corn wrapped in damp paper towels retain heat for 10 to 20 minutes if left in the wrapping.
You can keep the corn hot for longer than the indicated time with any of the methods, but there might be some loss of texture, moisture and flavor.