Kohlrabi is an attention-getter any way you slice it

If you want to spark a conversation at the farmers market, just ask a grower their opinion on the best way to prepare kohlrabi. Last week, there were several stands with piles of this odd vegetable. Its craggy exterior appearance (see photo), with octopus-like growths from a roundish bulb topped by green leaves, is as unusual as its name. And every grower has strong opinions on how to serve it.

Kohlrabi gets its name comes from the German words kohl (cabbage) and rube (turnip). It’s sometimes called cabbage turnip, stem turnip or marrow cabbage. However, it’s neither a cabbage nor a turnip, but a member of the brassica family that includes broccoli, cauliflower and kale. Unlike turnips, which form an underground bulb, the knobby part of the kohlrabi is actually the aboveground stem of the plant that sits on top of the soil.

Kohlrabi originated in Northern Europe and was first mentioned by an Italian botanist in the 1500s. It spread to countries around the Mediterranean Sea and made its way to Ireland, where it was widely cultivated by the early 1700s. English production started about a hundred years later, and the plant became known in the United States by the 19th century.

There are two varieties of kohlrabi, purple and green. The latter has a pale-green bulb and green leaves, while the former is purple and has purple veining in the leaves. The inside flesh of both types is creamy white. Its flavor has been described as a sweet-sharp combination of mild broccoli and celery root.

It may not appear to be the most delectable vegetable, but kohlrabi is nutrient-rich, with a subtle taste. When freshly harvested in the spring, a young kohlrabi bulb can be eaten raw, just like an apple. Its flavor is mild and slightly sweet with peppery hints, and its texture is similar to broccoli stems but juicier. Kohlrabi greens resemble collards and can be stir-fried or stewed.

Because kohlrabi is a hardy, cool-season vegetable, it grows in spring and fall, and is sometimes harvested in wintertime in the northeastern United States. Early kohlrabi is about the size of a baseball and has a mild, sweetish taste. In the fall, kohlrabi grows to the size of a softball, and it can be woody and fibrous if too large. Kohlrabi bulbs should be trimmed of their greens and stored in the fridge for a few weeks; just make sure they don’t become soft, a sign that they’re past their prime.

With cultivation across several continents, kohlrabi finds its way into a wide range of cuisines. But first, you have to prepare it for cooking. The initial step in disassembling this unwieldy vegetable is to cut off the leaves (save them for another dish if they’re crisp, but discard the limp or wilted). Next, trim away the stems that grow in all directions from the bulb. Slice off the base from the bottom, then remove the outer layer with a vegetable peeler until the white interior is exposed. 

At this point, you can cut your kohlrabi according to the dish you’re preparing. Slender matchsticks work well for fresh salads and stir-fries, one-inch chunks are good for roasting or in a stew, and thin strips are best if you’re planning to pickle it. I’ve included recipes for roasted kohlrabi, a hearty soup, and a German dish sometimes called “housewife style” that offers kohlrabi in a creamy sauce.

Roasted Kohlrabi

2 kohlrabi bulbs
2 t olive oil
1/4 t salt

Preheat oven to 375 F. Trim kohlrabi of leaves and stems. Remove the fibrous exterior skin with a vegetable peeler. Cut the bulb into 1-inch wedges. Place the pieces on a rimmed baking sheet in a single layer and drizzle with olive oil. Sprinkle with salt. Roast until tender and browned, about 30 minutes. Yield: 4 servings.

Kohlrabi Soup

3 lbs kohlrabi
1/4 C olive oil
1 t salt
1/2 t white pepper
1 diced onion
3 minced garlic cloves
3 C vegetable broth
1 bay leaf
1/2 t salt
1 lemon
Grated Parmesan cheese

Preheat oven broiler. Trim and peel kohlrabi; cut into 1-inch cubes. Arrange kohlrabi on a rimmed baking sheet. Drizzle with 2 T olive oil; sprinkle with salt and pepper. Broil until well browned, tossing halfway through, for a total of about 10 minutes. Meanwhile, heat the remaining 2 tablespoons oil in a saucepan over medium-high. Add onion and cook until soft, stirring frequently, about 7 minutes. Add garlic and cook for 1 minute. Add roasted kohlrabi, broth, bay leaf and salt. Bring mixture to a boil; reduce heat to medium and simmer until tender, about 20 minutes. Discard bay leaf. Using an immersion blender or working in batches in a food processor, purée soup until very smooth. Zest the lemon into the pot, then halve it and squeeze in juice. Ladle soup into bowls and top with grated cheese. Yield: 6 servings.

Kohlrabi Housewife Style

3 kohlrabi
2 C vegetable broth
2 T butter
2 T flour
1/4 t grated nutmeg
salt, to taste
chopped parsley, for garnish

Trim and peel kohlrabi. Cut into 1-inch cubes. Heat broth to boiling and add kohlrabi. Reduce heat and cook until soft, about 10 minutes. Drain kohlrabi, reserving liquid. Melt butter in a small saucepan. Add flour and cook, stirring constantly, until smooth. Add reserved liquid 1/2 C at a time, stirring until smooth after each addition. Stir in nutmeg and season to taste with salt. Stir in kohlrabi and simmer until heated through.
Serve garnished with parsley. Yield: 4 servings.