Field Corn vs. Sweet Corn: What’s the Difference?

When most people think of corn, sweet corn comes to mind—the fresh corn on the cob we like to boil or grill and slather with butter. However, of the over 90 million acres of corn planted in the US, sweet corn makes up less than 1% of the total crop. The rest is starchy and dry field corn, which is mostly used to feed cows.

Indigenous peoples originally cultivated corn’s wild ancestor, teosinte, over 9,000 years ago in what is now Mexico. That corn, called maize, was more similar to field corn, as sweet corn wasn’t cultivated until the mid-1700s.  The revered and versatile crop shaped the region’s culinary landscape and played a pivotal role in the history and development of North America.

Corn is a major agricultural commodity used extensively for livestock feed, biofuels, and food products. According to the Center for Food Safety, approximately 75% of processed foods on supermarket shelves contain some form of genetically engineered ingredients, and corn is a significant part of this statistic due to its widespread use in various forms such as high-fructose corn syrup, corn starch, and corn oil​.

Though sweet corn and field corn are related, they aren’t the same. Sweet corn and field corn are two distinct types of corn that differ in several aspects, including their purpose, flavor, texture, and cultivation practices. To learn more about the difference between the two, I spoke with Dave Smoke-McCluskey, a Mohawk chef and owner of Corn Mafia, a micro-milling project that explores native foodways. 

What Is Sweet Corn?

The fresh corn we enjoy grilled at cookouts and grab canned or frozen at the grocery store is sweet corn, which carries a gene that develops twice as much sugar as starchy types. “This corn has lots of natural sugars that make it delightful to eat straight off the cob or in a variety of dishes, like creamed corn,” says Smoke-McCluskey. Mexican and American cuisines (especially Southern) employ sweet corn in many dishes, including elote, corn chowder, and succotash.

Sweet corn is harvested in the summer while the kernels are still tender and juicy, before the sugar turns into starch. Smoke-McCluskey explains that sweet corn of the past had unstable sugar levels that converted into starch rapidly after harvest. “You had to eat it right away, and it tasted pretty bad by the time it got to the supermarket,” he says. “Sweet corn breeders have genetically modified today’s corn to produce much higher sugar levels and make it so that the conversion of sugar to starch occurs much slower,” which is a practice that began in the late 1960s. This longer shelf life means super-sweet varieties stay sweet for up to 10 days after harvest.

Sweet corn is available in white, light yellow, and bicolored varieties, but Smoke-McCluskey says there isn’t much of a discernible difference in flavor. “They’re all sweet and delicious.”

Mexican
Elotes (Grilled Mexican Street Corn)

cook time:


45 mins

serves:


4

When shopping for your sweet corn recipes at the grocery store or farmers market, he says to look for ears with fresh, green leaves but brown silks at the top—a sign that the corn was ripe when picked. The silk inside should still be soft and the kernels should be plump, not shriveled, though peeling back the husk to check the kernels understandably aggravates many corn vendors, so we don’t recommend this. Ideally, you can trust your vendor and know that the corn was harvested at its peak, but you can also feel for the full kernels through the husk.

If you’re growing your own sweet corn and don’t mind poking a hole in a kernel, you can tell it’s ready if you puncture a kernel and milk comes out. If the juice is clear, it’s too early; if there’s no juice, it’s too late. Cut it when the time is right because corn doesn’t continue to ripen off the stalk.

Pro tip: If your sweet corn is past its prime, Smoke-McCluskey says you can soak the cobs in sugar water (1/2 cup of white sugar per gallon of water) for a couple of hours to plump them back up.

What Is Field Corn?

Field corn can refer to any starchy variety, but most field corn in the US is dent corn, which gets its name from the dimple at the end of each kernel that forms as it dries out. 

Although field corn kernels start out soft like sweet corn, this variety is left to dry on the stalks in the field before harvesting in the fall once much of its sugar content has converted into starch, meaning it’s no longer sweet and juicy. And you won’t see any field corn at the grocery store.

“If you grab an ear of field corn and take a bite, you’ll probably chip a tooth,” says Smoke-McCluskey. About 40% of US dent corn is used as a feed grain for livestock, according to the USDA. Most of the rest is funneled into making ethanol fuel, while a small portion is milled to make foods and beverages, such as cereal, tortilla chips, whiskey, and grits. 

The kernels of commercial field corn are often a deep yellow-orange, referred to as “yellow gold.” However, heirloom varieties have kernels that span the colors of the rainbow. 

Bread
Easy Nixtamalized Corn Tortillas

Smoke-McCluskey likes to nixtamalize many kinds of field corn to make hominy. Nixtamalization, a.k.a. lyeing and washing, is a process in which field corn is boiled in water and hardwood ash, says Smoke-McCluskey. “The alkaline quality of the mixture softens the kernels enough to peel off their tough outer hull, making the corn more digestible and its nutritional benefits more bioavailable.” 

Among the Mohawk people of the Northeast, lyed corn is used in soups, stews, grits, mush, and cornbread. Smoke-McCluskey works with seed savers and growers, such as The Congaree Milling Company, to nixtamalize and coarsely grind hominy grits for sale to chefs and specialty stores. In Mexican cuisine, the nixtamalized mixture is ground into masa for tamales and tortillas.

Other Varieties of Corn

Most of the United States grows the exact same variety of corn from one seed, from one company. We’re not going to get into that here, but there are still many other flavors and nuances in different varieties of corn to be found, including indigenous field, flour, and flint varieties that are as delicious and nutrition-dense as they are beautiful. 

The Takeaway

Sweet corn is cultivated and harvested for its sweetness and tenderness, making it ideal for direct human consumption—such as boiling for corn on the cob or turning into chowder. Meanwhile, field corn is grown for its high starch content and versatility. Due to its tough texture and lower sugar content, it’s not typically consumed fresh but is commonly used as animal feed and in ethanol production. It is also nixtamalized and used to make masa, grits, mush, and cornbread.