It’s peak state-fair season in America, when the spotlight hits concession stand foods like deep-fried ranch dressing (yes, that’s a thing this year) and anything edible on a stick. But the real culinary action happens inside fair pavilions and expo centers, where tens of thousands of cake bakers, jam makers and vegetable canners compete.

In every state, there is an elite group of cooks who approach fair season with the focus of an Olympic athlete. They analyze categories and study how to impress judges. They practice pie recipes and pick only the best produce for their canning jars. Year after year, they take home not just a blue ribbon or two. They dominate.

We combed the country looking for these state fair all-stars. Here are seven of the big hitters:

Karen Delawder

Age: 71

Home kitchen: Rockingham County, Va.

Ribbon count: More than 1,000, from state and local fairs.

Day job: Retired from a variety of jobs. “Mostly I was just raising kids and getting them out in life.”

Notable wins: First place in the State Fair of Virginia contest sponsored by the state Egg Council for a magic flan cake. “I had worked five years to try to win that one.”

Top skill: Versatility. Ms. Delawder has won across categories including baking, food preservation and sponsored specialty-cooking competitions, like one from the Virginia Peanut Growers Association, in which the cooks tend to be more skilled and the judges more discerning.