Sweet potatoes, like fine cabernets, get better with age. Fresh out of the ground, they are considered "green" and have a high degree of starch. But if handled properly, their starch converts to sugar and, when cooked, sweet potatoes live up to their sugary appellation.
At harvest, they bruise easily and are coaxed from sandy soil with a rubber-coated chain. That is what Robert Knopp Jr., whose family has been growing sweet potatoes in Anne Arundel County for three generations, uses on his Severn farm. He puts sweet potatoes in a warehouse where they are "cured," basking in 80-plus-degree heat for several days, then cooling off at 55 degrees. "Once their skin has hardened," he said, "they can last all winter."
Many critters go after sweet potatoes. "Deer are the worst," Knopp said. "They eat the vines and some dig up the potatoes." Knopp harvests the crop from late August through October. He sells sweet potatoes at various farmers' markets, including the Sunday morning market in downtown Baltimore.
Once popular mainly with older customers who cook them in traditional dishes, sweet potatoes have recently caught the favor of a younger crowd that is interested in their high nutritional content. "The peak demand is at Thanksgiving," Knopp said. "There is a rush around Christmas, and some call for them at Easter." He is able to provide sweet potatoes at Easter, pulling them out of winter storage, because this is a crop, Knopp said, "that likes to hang around."
Varieties : In Fresh From the Farmers' Market, Janet Fletcher divides sweet potatoes into two camps - moist-fleshed (mistakenly called yams) and dry-fleshed varieties. Beauregard is a popular, orange-colored, moist-flesh sweet potato. Redmar is a Maryland-born variety. O'Henry is a common dry-flesh, yellow sweet potato. But Knopp says the prize sweet potato of Maryland is the dry-flesh Hayman.
Selection: Look for firm potatoes. Avoid those with soft spots. Dirt on the skin is a good sign, indicating little handling and less chance of bruising.
Storage: Store in a cool, dark, well-ventilated place.
Cooking: Rub with butter or oil, wrap in foil, and roast until tender in a charcoal fire.
roasted sweet potatoes
4 sweet potatoes, 8 to 10 ounces each, cleaned but not peeled
2 tablespoons butter or sunflower oil
Prepare a fire in a barbecue kettle cooker with lump charcoal, or preheat oven to 400 degrees.
Rub sweet potatoes with butter or oil. If using the grill, wrap them with 2 layers of aluminum foil. If using the oven, set the potatoes unwrapped on a baking sheet.
Place wrapped sweet potatoes directly in glowing coals. In the oven, place pan on a rack.
Roast until one "test" potato can be pierced easily with a skewer - about 30 minutes in barbecue cooker, about 45 minutes in the oven.
Potatoes cooked in coals will have a slightly smoky flavor. Both cooking methods caramelize the potatoes' natural sugar.
Use tongs to remove potatoes from heat. Wear oven mitts to remove foil. Serve immediately.
Adapted from "Local Flavors," by Deborah Madison
Per potato: : 297 calories, 5 grams protein, 6 grams fat, 4 grams saturated fat, 58 grams carbohydrate, 8 grams fiber, 15 milligrams cholesterol, 83 milligrams sodium