Once it was only cabbage's pretty cousin all ornamental cuteness with no culinary career. Ruffled and often purple, it sat purely as decoration in winter flower gardens. Occasionally, it would make a guest appearance as garnish on a plate as a splashier alternative to parsley.
Now, kale is known as a vegetable powerhouse. Its bountiful antioxidants have been linked to fighting several cancers and conquering myriad maladies. It's even become a healthy fast-food alternative as crunchy kale chips.
"Kale chips are something of a culinary miracle: A harsh, bitter green becomes a paper-thin chip that melts in your mouth," said Lindsay Landis, author of "Breakfast for Dinner" (Quirk Books, 160 pages, $19.95). "The key to making these snacks extra crisp is drying them completely before baking."
Kale sales particularly of the Tuscan black or "dinosaur" variety have skyrocketed, said Jim Mills of Sacramento's Produce Express. "It's huge. From last year, sales are up easily five times. The main source is still small organic growers."
Although grown year-round, kale is at its peak of availability in late winter. Cold weather makes kale taste sweeter.
"It's still a fairly seasonal crop," Mills said. "Chefs use more in winter than summer."
Chefs serve it alongside braised short ribs, in frittatas and under scallops. Wolfgang Puck served kale salad at Sunday's post-Oscar gala.
Before this boom in popularity, the biggest U.S. kale buyer was Pizza Hut, which used the dark green variety to decorate its salad bars.
But anything spinach can do, kale can do often with more vitamins and minerals. Per calorie, kale has more iron than beef and more calcium than milk.
In addition to the dark green curly kinds, look for Russian red kale, smooth-leafed Siberian kale and Tuscan (a.k.a. lacinato) kale with long, straight leaves.
Nutrition: Kale comes packed with nutrients but few calories and virtually no fat. One cup of chopped raw kale contains 33 calories, yet contains twice the recommended daily allowance of vitamin A. It also contains more than a full day's supply of vitamin C and almost seven times the daily dose of vitamin K. Kale also is rich in vitamin B6, calcium, potassium, copper and manganese. Plus it provides a lot of fiber.
Because it's so dense in nutrients, kale is considered among the best "superfoods." It contains 45 different flavonoids; those antioxidants help fight cancers of the bladder, breast, colon, ovary and prostate. Steamed kale also may help lower cholesterol levels.
On the down side, kale contains high concentrates of oxalates. People with kidney or gallbladder problems should avoid kale.
Selection: Look for dark, firm leaves and moist, sturdy stems. Leaves should not appear wilted, yellow or full of little holes. Smaller leaves tend to be milder and more tender than large leaves. Due to its high water content, kale greatly reduces when cooking; 1 cup raw becomes 1/4 cup cooked. Before preparation, allow a half-pound raw per person.
Storage: Kale looks tough, but wilts easily. Keep it cold. In the refrigerator crisper drawer, store unwashed kale in a plastic bag; squeeze out as much air as possible. Kale will keep at least five days; the longer the storage, the more bitter it becomes. Wash just before using. Kale also can be blanched and frozen for later use.
Preparation: Because of its curly texture, kale needs to be washed carefully to remove grit. Rinse under running water one leaf at a time.
To get the most health benefits out of kale, wash the leaves, sprinkle them with lemon juice, then let them sit at least five minutes before using. That little squeeze of lemon can enhance kale's concentration of phytonutrients and also improves flavor.
Kale can be eaten raw in salads or cooked (steamed, braised, roasted or stir-fried). Steamed kale can be used as a substitute for cooked spinach in most recipes. To steam, bring 2 inches of water to boil in the bottom of a steamer pot. Remove midrib of kale leaves and chop into half-inch pieces. Steam kale for 5 minutes. Toss with butter, olive oil or other dressing, or use in recipes.
Possible combinations: Serve steamed kale with chopped apple, walnuts and balsamic vinegar. Or toss steamed kale with pine nuts, feta cheese, olive oil and cooked pasta. Or the traditional standby: Steamed kale with butter, topped with crumbled bacon.
Kale chips: The key to crisp kale chips: dry leaves. Use a salad spinner. Pat with paper towels. Get the moisture out of those curly cracks.
Preheat oven to 400 degrees. Remove large stems and center rib from leaves. Cut leaves into 2-inch pieces. Toss leaves in 2 tablespoons olive oil and arrange pieces in a single layer on a foil-lined cookie sheet. Bake for 5 to 7 minutes or until crisp but not brown around the edges. Sprinkle with salt and serve. (Another version of kale chips is on this page, above left.)
Kale lore: A cabbage cousin, today's kale descended from wild cabbages in Asia Minor. Celtic travelers are believed to have introduced kale to Europe before 600 B.C.
The ancient Romans farmed curly kale. That also was a major vegetable for peasants in the Middle Ages. In the 1600s, English immigrants brought kale with them to the New World.
For centuries, kale has been synonymous with Scotland. Traditionally, every country garden should have a patch (called a "kaleyard"). If a Scotsman invites you "to kale," he means come to dinner, although kale may not necessarily be on the menu.