Kohlrabi is a biennial vegetable, a low, stout cultivar of wild cabbage.
Its unique name is derived from the German word for cabbage (kohl) and turnip (rabi).
The kohlrabi originates from the northeast of Europe. Its consumption has stayed mainly in this area, while in others it is hardly known.
The first description of kohlrabi was by a European botanist in 1554.
By the end of the 16th century it was known in Germany, England, Italy, Spain, Tripoli, and the eastern Mediterranean. It is said to have been first grown on a field scale in Ireland in 1734, in England in 1837.
In the United States, records of its use go back to 1806.
The plant is easy to grow, is remarkably productive, and an ideal garden vegetable if one does not make the mistake of planting too much of it.
Kohlrabi is a biennial plant that is usually grown as a cool-season annual. The waxy lobed or wavy leaves emerge from the swollen stem and feature long petioles (leaf stems). If left to mature, the plant bears yellow four-petaled flowers in small clusters; the elongated fruits are known as siliques.
Plant height ranges from 25 to 40 centimeters (10 to 16 inches). The edible part of the kohlrabi is an enlargement of a small portion of the above-ground stem. In shape the swollen stem varies from nearly round to a flattened globe; in outer colour, from greenish white to reddish purple.
Kohlrabi is best harvested for food when this enlargement is from 5 to 10 centimeters (2 to 4 inches) in diameter; the approximate weight is 150 g. The flesh is similar to that of the turnip but is sweeter and milder.
The largest kohlrabi was grown by Scott Robb (USA) and weighed 43.98 kg (96 lb 15 oz) at the Alaska State Fair, Palmer, Alaska, USA, on 30 August 2006.
There are several varieties commonly available, including White Vienna, Purple Vienna, Grand Duke, Gigante, Purple Danube, and White Danube.
The inside flesh of kohlrabi is slightly sweet, and crispy. The taste of kohlrabi is similar to broccoli stems or cabbage heart, but sweeter.
The bulbous kohlrabi stem is frequently used raw in salad or slaws.
There are only 47 calories in 100 grams (3.5 ounces) of kohlrabi.
Kohlrabi is a good source of vitamin A, vitamin C and vitamin K, as well as B-vitamins. It also contains copper, manganese, iron, potassium, dietary fiber and calcium, and is rich in antioxidant compounds like phytochemicals and carotenes as well.
The health benefits of kohlrabi include healthy digestion, weight loss, antioxidant properties, boosts energy, increase circulation, anemia prevention, improves eye health, protecting muscle and nerve function, lowers blood sugar levels, boost the immune system and prevent cancer.
Kohlrabi is a commonly eaten vegetable in German-speaking countries and American states with large ancestral German populations such as Wisconsin, but is also very popular in the northern part of Vietnam where it is called, and in eastern parts of India (West Bengal) and Bangladesh.
In Cyprus it is popularly sprinkled with salt and lemon and served as an appetizer.