In 2012 Pizza Hut bought about 14,000 pounds of kale purely as decoration
For most of the twentieth century Americans treated kale as garnish, and a pizza chain once bought roughly seven tonnes just to dress its salad bars. Only from the 1990s did it become a fashionable green. Elsewhere it had been dinner for millennia; in some Scots dialects the word for kale simply means food.
Kale is a cabbage that never bothered to form a head. It belongs to Brassica oleracea, the species behind many familiar vegetables, but sits closer to wild cabbage than most of its domesticated relatives. People in the eastern Mediterranean and Anatolia were growing it for food by 2000 BCE at the latest, and Greece already had curly and flat-leaved types in the 4th century BC. The Romans called these Sabellian kale, and they are regarded as ancestors of today's varieties. The name descends through Middle English cale from the Latin caulis.
Its toughness made it valuable. Kale is usually biennial, survives down to about minus 15 degrees Celsius and often tastes sweeter after heavy frost. One variety earned the name hungry gap for feeding households during the lean late-winter stretch when little else could be picked. During the 1800s Russian traders carried Russian kale to Canada, and from there it spread south. The botanist David Fairchild, who is credited with introducing it to Americans from Croatia, personally disliked cabbages of every kind.
Forms vary from Scots curly kale to the bumpy cavolo nero, also called dinosaur kale, and flat red Russian types. Ornamental kales with pink, white or violet centres are edible, just less pleasant to chew. Raw kale is mostly water; a 100 gram serving supplies 3.7 times the daily value of vitamin K, and boiling reduces many nutrients, whereas steaming or stir-frying keeps glucosinolates largely intact.
Winter traditions abound. Northern Germans go on a Kohlfahrt, a woodland hike ending at an inn with kale and sausage. The Dutch mash it with potatoes, the Irish make colcannon for Halloween, and the Portuguese serve it finely shredded in caldo verde. To be off one's kail in Scotland means too ill to eat. In Kilmaurs, legend says, villagers sold prized kale seed to envious neighbours only after roasting it on a shovel so it would never sprout.
Source: Kale
