—by Jerry McClelland
In the Midwest we make a bit of a fuss over sweet corn. It is an iconic food of summer and worth the eleven-month interval between harvests. It is easy to take it for granted, but it was by happy accident that we have it at all.
Some corn in Peru slipped a genetic cog about 10,000 years ago. A mutation on chromosome 4, called the sugary (su) allele, made the corn sweet rather than starchy. Someone discovered one of these sweet tasting ears among the others being harvested in the early period of corn cultivation. People in Peru traded the seeds with others here and there, and after a while the corn showed up in New England.
From seed saving to catalogs
In the 1700s European Americans were growing their food and saving seeds for the next year. By the time the Declaration of Independence was being signed in Philadelphia, merchants were selling seeds there and in other cities. Not long after, seeds were sold in catalogs.
From white to yellow
During the 1800s, European Americans preferred white sweet corn such as Country Gentleman. Perhaps they preferred it because horses ate yellow field corn, and many people wish to put a good distance between what they eat and what work animals eat.
In the 1920s, when Americans were driving cars and forgetting about horses, the W. Atlee Burpee Seed Company included Golden Bantam, a lovely yellow corn, in its catalog. It was advertised as having a buttery flavor and not needing butter, which was expensive. Golden Bantam was tasty, adaptable to many growing conditions, and fairly disease resistant. Yellow sweet corn replaced white as the favorite over time.
From heirloom to hybrid
At this point there were hundreds of varieties of sweet corn, which we now call heirloom (su),
meaning they were old varieties that had been grown in gardens and small fields throughout much of the Americas over centuries.
The varieties changed some, depending on what kind of corn was growing near them that might have influenced pollination. In this way the number of varieties also increased. Heirloom corn was genetically diverse and was the basis for all the corn that came later. It was only about 10–15 percent sugar, and it turned starchy very quickly, so it was best eaten immediately after harvest.
Corn-breeding expanded from gardens and small fields to labs and experiment plots in the mid-1900s. Corn has 32,000 genes on 20 chromosomes. Researchers have tweaked seven genes, in addition to the sugary (su) gene that jumped the cog in Peru, to ratchet up the sweetness and to enhance the creamy texture and tenderness of the kernels.
There have been three major waves of innovation over the last 60 years that have resulted in more varieties, which are grouped as sugar enhanced, supersweet, and synergistic. As the names of the groups imply, there is a
general trend of the succeeding waves to become sweeter, so that some corn can be 50 percent sugar. At the same time, attention was given to improving shipping and storing qualities to fit an industrial food model.
Corn at the co-op
Hampden Park Co-op will have bi-color Xtra-Tender sweet corn this summer. It is delectable, with sweet, creamy, tender kernels, and it freezes well.
Al Weinrich is the front man for Wisconsin Growers, a loosely organized farmers’ co-op. The corn headed our way is growing from seeds that came from Johnny’s Selected Seeds, based in Winslow, Maine. The corn is growing near River Falls, Wisconsin, on an organic farm certified by Nature’s International Certification Services. Al will truck it to HPC within hours of its being harvested.
If the weather stays on course, be on the look-out for the corn from early August through early September. For some, sweet corn, a little salt, pepper, and butter make a meal. Others add bacon and tomato sandwiches. Maybe a little home-brewed beer or iced tea would make the meal a
[Jerry McClelland grew up on a farm in Missouri at a time when most rural families ate and drank what they produced, not knowing to call it either local or sustainably grown. She is retired and writes occasional articles about the natural history and cultural meanings of food.]