Food of the Week: Kale
Posted on May 29, 2012
Kale or borecole is a form of cabbage (Brassica oleracea Acephala Group), green or purple, in which the central leaves do not form a head. It is considered to be closer to wild cabbage than most domesticated forms. The species Brassica oleracea contains a wide array of vegetables, including broccoli, cauliflower, collard greens, and brussels sprouts. The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically.
The name borecole most likely originates from the Dutch boerenkool (farmer’s cabbage). Some varieties can reach a height of six or seven feet; and some are compact and symmetrical and of good quality for eating. Many however are coarse, have undesirable coloring, and are unappealing and indigestible. Most kale is either annuals or biennials, and is raised from seeds, which, in size, form, and color, resemble those of the cabbage.
Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich incalcium. Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical with potent anti-cancer properties. Boiling decreases the level of sulforaphane; however, steaming, microwaving, or stir frying do not result in significant loss. Along with other brassica vegetables, kale is also a source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells. Kale is also a good source of carotenoids.
Until the end of the Middle Ages, kale was one of the most common green vegetables in all of Europe. Curly leafed varieties of cabbage already existed along with flat leafed varieties in Greecein the fourth century BC. These forms, which were referred to by the Romans as Sabellian kale, are considered to be the ancestors of modern kales. Today one may differentiate between varieties according to the low, intermediate, or high length of the stem, with varying leaf types. The leaf colours range from light green through green, dark green and violet-green to violet-brown. Russian kale was introduced into Canada (and then into the U.S.) by Russian traders in the 19th century.
During World War II, the cultivation of kale in the U.K. was encouraged by the Dig for Victorycampaign. The vegetable was easy to grow and provided important nutrients to supplement those missing from a normal diet because of rationing.
Kai-lan, a separate cultivar of Brassica oleracea much used in Chinese cuisine, is somewhat similar to kale in appearance and is occasionally called “kale” in English.
As of 2012, kale is not currently grown or sold in France. The Kale Project, a movement started by an American expat in Paris, is aiming to find farmers in Paris and bring kale into Paris markets and progressive restaurants.
Kale freezes well and actually tastes sweeter and more flavourful after being exposed to a frost.
Tender kale greens can provide an intense addition to salads, particularly when combined with other such strongly flavoured ingredients as dry roasted peanuts, tamari-roasted almonds, red pepperflakes, or an Asian-style dressing.
In the Netherlands, it is very frequently used in a winter dish (a stamppot), as a traditional Dutch dish called boerenkool.
In Ireland, kale is mixed with mashed potatoes to make the traditional dish colcannon. It is popular on Halloween when it is sometimes served with sausages. Small coins are sometimes hidden inside as prizes.
Kale is a very popular vegetable in China, Taiwan, and Vietnam, where it is commonly stir-fried with beef.
A traditional Portuguese soup, caldo verde, combines pureed potatoes, diced kale, olive oil, broth, and, generally, sliced cooked spicysausage. Under the name of couve, kale is also popular in Brazil, in caldo verde, or as a vegetable dish, often cooked with carne seca(shredded dried beef). When chopped and stir-fried, couve accompanies Brazil’s national dish, feijoada.
In East Africa, it is an essential ingredient in making a stew for ugali, which is almost always eaten with kale. Kale is also eaten throughout southeastern Africa, where it is typically boiled with coconut milk and ground peanuts and is served with rice or boiled cornmeal.
A whole culture around kale has developed in north-western Germany around the towns ofBremen, Oldenburg and Hannover. There, most social clubs of any kind will have a Grünkohlfahrt (“kale tour”) sometime between October and February, visiting a country inn to consume large quantities of boiled kale, Kassler, Mettwurst and Schnapps. These tours are often combined with a game of Boßeln. Most communities in the area have a yearly kale festival which includes naming a “kale king” (or queen).
Curly kale is used in Denmark and southwestern Sweden to make (grøn-)langkål (Danish) orlångkål (Swedish), an obligatory dish on the julbord in the region, and is commonly served together with the Christmas ham (Sweden). The kale is used to make a stew of minced boiled kale, stock, cream, pepper and salt that is simmered together slowly for a few hours. In Scotland, kale provided such a base for a traditional diet that the word in dialect Scots is synonymous with food. To be “off one’s kail” is to feel too ill to eat. In Sweden, it is also commonly eaten as a soup, with a base of ham broth and the addition of onion and pork sausages.
In Montenegro collards, locally known as rashtan is a favorite vegetable. It is particularly popular in winter, cooked with smoked mutton (kastradina) and potatoes.
In the Southern United States, kale is often served braised, either alone or mixed with other greens, such as collard, mustard, or turnip.
Most recently in the United States, kale has seen a rise in popularity beyond health-food/vegan/raw food enthusiasts. Urban areas like New York City, LA, Miami etc have popularized the “raw kale salad” and it is a common staple on restaurant menus. The infamous “kale massage” (http://thekaleproject.com/) is now part of daily lexicon with people that are starting to incorporate kale into their cooking. Along with the raw kale salad, “kale-chips” – baked kale pieces with salt/pepper – have become popular.
In Japan, kale juice (known as aojiru) is a popular dietary supplement.