Kohlrabi

Two primary varieties dominate the market: green (or white) kohlrabi, with pale chartreuse skin and creamy white flesh, and purple kohlrabi, sporting a stunning violet exterior that gives way to the same ivory interior. The purple variety is slightly more cold-tolerant and often considered marginally sweeter, though differences are subtle. Beyond color, varieties are bred for early maturity (fast-growing spring types like 'Early White Vienna') or storage capability (larger, slower-maturing fall types like 'Gigante' or 'Superschmelz,' which can grow to impressive sizes while maintaining tenderness). Some heirloom varieties feature particularly tender flesh or enhanced sweetness.

Kohlrabi's journey through culinary history is relatively recent compared to its brassica cousins. The first written European record appears in 1554, when Italian botanist Pietro Andrea Mattioli noted that it had "come lately into Italy"—suggesting its development as a distinct cultivar occurred in the late medieval period, likely in Northern Europe. By the close of the 16th century, kohlrabi had spread across the continent, establishing itself in Austria, Germany, England, Italy, Spain, and the eastern Mediterranean. Its name, meaning 'cabbage turnip', comes from the Italian cavolo rapa, adapted into German as a blend of "Kohl" (cabbage) and "Rübe" (turnip). It reached India and South Asia in the 17th century, where it became known as "knol khol," and arrived in the United States in the early 19th century. Unlike cabbage or kale, which trace their cultivation back millennia, kohlrabi represents a relatively modern example of selective breeding—farmers deliberately cultivating wild cabbage for its swollen stem rather than its leaves or flower buds.

Kohlrabi's distinctive bulbous form results from the plant's lateral meristem—the growth tissue responsible for stem thickening—being selectively enhanced over centuries of cultivation. This swollen stem serves as a storage organ, accumulating water and sugars that give kohlrabi its characteristic juicy crunch. The vegetable's mild sweetness intensifies after frost exposure, as cold temperatures trigger the conversion of starches to sugars—a survival mechanism that lowers the cellular freezing point. Like all brassicas, kohlrabi contains glucosinolates, sulfur-containing compounds that break down into isothiocyanates when cells are damaged (during cutting or chewing). These compounds are responsible for the subtle peppery bite. The purple variety owes its color to anthocyanins—the same water-soluble pigments found in red cabbage and blueberries—which are confined to the skin and do not affect the flesh's flavor or nutrition.

Kohlrabi represents one of the more sustainable vegetable choices available. As a cool-season crop with a quick growth cycle (45-60 days to maturity), it fits well into organic and regenerative farming systems, though it needs steady, even moisture to stay tender. Its short growing season means it spends less time in the field than cabbage, although it is affected by the same pests, such as flea beetles and cabbage root fly. The vegetable thrives in temperate climates across Europe, North America, and Asia, making locally-sourced kohlrabi readily available in most regions during spring and fall. For the most environmentally conscious choice, seek out kohlrabi from local farmers' markets or CSA programs, where shorter supply chains reduce transportation emissions. Organic and biodynamic certifications (such as Demeter) ensure cultivation without synthetic pesticides or fertilizers. The entire plant is edible—bulb, leaves, and even peels for stock—making kohlrabi an excellent choice for zero-waste cooking practices.