As the local growing season kicks into gear, farmers are harvesting apple-green knobs of kohlrabi along with the more commonly sought leafy lettuces and willowy herbs.
“It’s just something that’s part of the routine. People in this area have raised it for a number of years,” said Ralph Formisano of Formisano Farms in Buena, down in Atlantic County, who began picking his kohlrabi last week. “We’ve raised it since we’ve been here, which is 55 years, and my father grew it in Moonachie long before that.” Farmers in the southern part of the state typically take a summer hiatus from growing the cool-loving kohlrabi, then plant another crop in late August or early September for harvesting from October through frost.
In contrast to his colleagues to the south, Kurt Alstede of Alstede Farms in Chester, up in Morris County, expects to pick his kohlrabi, planted in fields with northern exposure and some shade, from June straight to season’s end. “If we do our job right, we’ll have it at least to the end of October,” he said. Yet, he added, “It’s not an extremely popular crop. We probably grow 20 to 30 times more broccoli than we do kohlrabi.” Like broccoli, kohlrabi is a cole crop — that is, a member of the brassica family of vegetables, which includes cabbage and cauliflower. Topped with collard-like leaves, it is characterized by its enlarged stem, which is often referred to as a bulb, even though it grows above ground.
Those who know kohlrabi best tend to come from Hungary, Germany, Austria, Russia, China and India. Stateside, it’s been cultivated at least since the beginning of the 19th century, but “a lot of people don’t know how to cook with it,” said Alstede.
Its German name is a double-barreled reference to its lineage (cabbage — kohl) and its appearance (turnip — rabi), but kohlrabi is not, as many assume, a cross between the two vegetables, for they are not even members of the same species.
The average American’s lack of familiarity with kohlrabi is one reason why it’s not commonly found on restaurant menus, explained Thomas Ciszak, executive chef at The Copeland Restaurant in Morristown, who grew up with homegrown kohlrabi in his native Germany. “I love it raw,” he said. But even he can’t sell a kohlrabi salad. “People like to eat what they know,” he said.
Ciszak, however, does serve kohlrabi batons cooked with dry vermouth and cream, topped with caviar. “The fishy saltiness goes really super with kohlrabi,” he said. He also serves a kohlrabi soup in which he blends the vegetable with cream, vermouth, white wine and shellfish stock.
The taste of kohlrabi is often compared to that of mild cabbage. “But I don’t want to say it’s mild. People confuse ‘mild’ with ‘no flavor,’” said Ciszak. “It’s very delicate, very elegant, very gentle.”
Like collard greens, the leaves of the kohlrabi plant also can be cooked, as long as their tough ribs are removed first. Ciszak, however, prefers to use only the tender innermost leaves. When preparing the bulbous stems, he cautions against over-peeling, for the tops are quite delicate. Over-cooking is another no-no. “The more you cook it, the less sharp and fragrant it is,” he explained.
In “Melissa’s Great Book of Produce” (Wiley, 2006), author Cathy Thomas suggested roasting two pounds of diced kohlrabi, tossed with olive oil and salt, in a 450-degree oven for 35 minutes. In addition, she noted, kohlrabi works well in vegetable soup and can be combined with potatoes in an au gratin preparation.
At market, green varieties are most commonly seen, although there are purple ones as well. Regardless of color, the bottoms should be smooth, with no cracking; the leaves, vibrant and bright green, with no sign of yellowing. “The small bulbs are certainly more tender,” said Formisano. A kohlrabi bigger than a tennis ball is best left on the shelf, for it is likely to be woody and tough.
Once home, the tops should be lopped off, and the leaves and bulbs should be wrapped separately, ideally in perforated plastic, and refrigerated until ready to use. “It’s a crop that holds its quality quite well. It has a very good shelf life, which is why it was popular in old Europe” said Alstede. An excellent source of vitamin C and potassium, high in fiber, and very low in calories (about 40 per cup), kohlrabi, even today, is worth keeping.