Ontario grows three types of sweet corn: normal, sugar-enhanced and supersweet. Each contains three different colour groups: yellow, bicolour (yellow-and-white) and white.
Sugar content of the traditional normal type varies from 9 to 16 per cent, compared to the 14 to 44 per cent range in the others.
The natural sugars in normal and sugar-enhanced corns eventually convert to starch, causing the kernels to lose sweetness and become tough. But that doesn't happen with supersweet corn, making it particularly desirable when there's a delay between harvest and consumption.
Some of the dozens of varieties grown in Ontario are Miracle, Kandy Korn, Earlyvee, Flavorvee, Escalade, Silver Queen, Phenomenal, Seneca, Champ, Horizon and Extra Early Supersweet.
Corn is good source of folate and contains fibre, Vitamin C, niacin and thiamine. An average ear of corn has 83 calories.
Also known as maize, grain corn was the chief source of nourishment for thousands of years, sustaining the Mayas, Aztecs, Incas and the Indian peoples of North and South America.
After the early settlers arrived in America, corn was introduced to Europe and is now cultivated in Africa, China, Russia and other parts of the globe.
Originally corn was grain corn; now it's used for cattle feed and a variety of industrial applications. Sweet corn is a relatively recent development, becoming popular chiefly since the American Civil War period.
Buying and storing
Fully ripe sweet corn has bright green, moist husks. The silk should be stiff, dark and moist. You should be able to feel individual kernels by pressing gently against the husk.
Ideally, corn should be cooked and eaten immediately after picking since its natural sugar declines as soon as it has been picked.
Between purchasing and cooking, keep the corn moist and cool. Pack in a cooler for the trip home from farm or market and immediately refrigerate in a plastic bag. Use within two or three days.
Before cooking, remove husk and any remaining bits of silk. Trim the cobs, remove undeveloped tip ends or any disfigured kernels. If boiling fresh sweet corn, cook for 3 to 4 minutes for young cobs, 5 to 7 minutes for mature cobs. If steaming, cook corn for 7 to 11 minutes, depending on size (small cobs, 7 minutes; medium, 9 minutes; large, 11 minutes).
To barbecue, soak four large cobs, with green husks, in cold water for at least 30 minutes. To avoid flare up, trim off any loose strands of husks. Place on grill over medium-high heat; close lid and grill, turning frequently, for about 20 minutes or until husks are charred and corn is tender. Let cool slightly, then cut kernels off the cobs. For charred marks, place the stripped cobs on the grill for a few minutes until brown on all sides.
To microwave, husk sweet corn and place cobs on microwaveable baking dish, and cover with plastic wrap. If cooking only 1 or 2 cobs, wrap individually. Microwave on High power 2 minutes per cob or just until tender. Let stand 2 minutes before unwrapping.
Corn can also be frozen after a brief blanching.
Sweet corn is an excellent addition to mixed vegetable dishes such as succotash, rich "puddings" and crisp fritters. It's well-suited to flavourful sweet relishes. Baby ears of corn have long been prepared as tender pickles.