Knowing the type of corn rather than just its variety provides useful information about its level of sweetness and its shelf life.
Standard varieties convert to starch quickly and therefore should be eaten as close to picking as possible. Names to look for: Country Gentleman, Silver Queen, White Magic.
Sugar-enhanced varieties have a higher sugar content than standard corn. Their sugars begin to convert several days after picking. These varieties are often grown for direct sale, such as at farmers markets. Names to look for: Temptation, Silver King, Argent.
Supersweet corn varieties maintain high sugar content for eight to 10 days after picking, making them popular for wholesale production and grocery stores. Names to look for: Devotion, Tahoe, 81W, 372A and 378A.