Kohlrabi, often called the German turnip, is a fascinating vegetable that belongs to the Brassica family, which also includes cabbage, broccoli, and kale. Its bulbous stem, which grows above ground, is the edible part we typically consume. While kohlrabi might seem like an exotic ingredient, it’s surprisingly versatile and can be enjoyed raw or cooked. What many people don’t realize is that kohlrabi comes in two main varieties: purple and green. But what exactly distinguishes these two colorful cousins?
A Deep Dive into Appearance
The most obvious difference between purple and green kohlrabi lies in their outer skin color.
The Purple Hue
Purple kohlrabi boasts a vibrant, eye-catching purple skin. This exterior color can range from a light lavender to a deep, almost regal, purple. The intensity of the purple can sometimes be influenced by factors such as soil composition, sunlight exposure, and the specific cultivar. The striking purple color makes it a visually appealing addition to any dish. However, it’s crucial to note that this vibrant color is only skin deep.
The Green Shade
Green kohlrabi, on the other hand, has a pale green to light green skin. This color is more subtle and perhaps less dramatic than its purple counterpart. Just like the purple variety, the exact shade of green can vary depending on growing conditions and the particular cultivar. The green variety offers a more understated aesthetic.
The Inside Story: Color Consistency
Despite the differences in exterior color, both purple and green kohlrabi share a similar interior: a pale white to yellowish-white flesh. The flesh of both varieties is crisp and juicy. Regardless of whether you choose purple or green, you can expect a similar texture on the inside. This consistency in the flesh is important to remember when considering their culinary applications.
Size and Shape Considerations
While not directly tied to color, it’s worth noting that both purple and green kohlrabi typically share a similar shape – a round, bulbous stem. The size can vary depending on the maturity of the vegetable, with smaller kohlrabi generally being more tender and flavorful. Both varieties are best harvested when they are relatively small to ensure optimal texture and taste.
Taste and Texture Nuances
Beyond the visual differences, subtle nuances exist in the taste and texture of purple and green kohlrabi.
Flavor Profiles Compared
While both varieties share a mild, slightly sweet, and turnip-like flavor, many people report that green kohlrabi tends to be a touch milder and sweeter than the purple variety. The green kohlrabi is often described as having a slightly more delicate flavor. The purple variety can sometimes have a slightly more assertive or even peppery undertone.
Texture Examination
Both purple and green kohlrabi share a crisp and juicy texture when raw. When cooked, they become softer and more tender. Some people find that purple kohlrabi can be slightly tougher than the green variety, especially if it is more mature. Harvesting at the right size is crucial to ensure optimal texture, regardless of the color. Overgrown kohlrabi, whether purple or green, can become woody and less palatable.
Nutritional Value: A Side-by-Side Comparison
Kohlrabi is a nutritional powerhouse, packed with vitamins, minerals, and fiber. Both purple and green varieties offer similar nutritional benefits, though some minor differences may exist.
Key Nutrients in Both Varieties
Both purple and green kohlrabi are excellent sources of Vitamin C, which is crucial for immune function and collagen production. They also contain dietary fiber, which aids in digestion and promotes satiety. Furthermore, they are good sources of potassium, an essential mineral for maintaining healthy blood pressure. Both varieties are low in calories and fat, making them a healthy addition to your diet.
Antioxidant Activity: Purple Kohlrabi’s Advantage
Purple kohlrabi owes its vibrant color to anthocyanins, which are powerful antioxidants. Antioxidants help protect the body against damage from free radicals, which can contribute to chronic diseases. The presence of anthocyanins gives purple kohlrabi a potential edge in terms of antioxidant activity. While green kohlrabi also contains antioxidants, the concentration of anthocyanins is significantly higher in the purple variety.
Other Nutritional Considerations
While the differences are generally minor, the exact nutritional content can vary slightly depending on factors such as soil quality and growing conditions. However, both purple and green kohlrabi are considered to be highly nutritious vegetables that offer a wide range of health benefits. Incorporating either variety into your diet can contribute to overall well-being.
Culinary Applications: Exploring the Possibilities
Both purple and green kohlrabi can be used in a variety of culinary applications, offering versatility in the kitchen.
Raw Preparations: Salads and Slaws
Both varieties can be enjoyed raw, adding a crisp and refreshing element to salads and slaws. The mild flavor of kohlrabi pairs well with a variety of dressings and other ingredients. When using raw kohlrabi, it’s essential to peel the outer skin, as it can be tough. Grating or thinly slicing the kohlrabi makes it easier to eat and incorporate into your favorite raw dishes.
Cooking Methods: Roasting, Steaming, and Sautéing
Kohlrabi can be cooked using various methods, including roasting, steaming, and sautéing. Roasting brings out the sweetness of the vegetable, while steaming helps to retain its nutrients. Sautéing with other vegetables and spices can create a flavorful and satisfying side dish. Cooking softens the texture of kohlrabi and mellows its flavor.
Creative Culinary Uses: Soups and Stir-fries
Kohlrabi can also be added to soups and stir-fries for added texture and flavor. Its mild flavor complements a wide range of ingredients, making it a versatile addition to many dishes. Experimenting with different culinary applications is a great way to discover your favorite ways to enjoy kohlrabi. Both the bulb and the leaves are edible, offering even more culinary possibilities. The leaves can be cooked like spinach or kale.
Visual Appeal: Using Color to Your Advantage
The vibrant purple color of purple kohlrabi can add a visual appeal to dishes. Consider using it in salads or slaws where the color can be showcased. The purple variety can elevate the aesthetic of your culinary creations. Green kohlrabi, on the other hand, offers a more subtle and understated aesthetic.
Growing Considerations: From Seed to Harvest
Growing kohlrabi is relatively easy, making it a popular choice for home gardeners. Both purple and green varieties have similar growing requirements.
Optimal Growing Conditions
Kohlrabi thrives in cool weather and requires well-drained soil. It prefers full sun but can tolerate partial shade. Planting kohlrabi in the spring or fall allows it to mature in cooler temperatures. Regular watering is essential to keep the soil moist but not waterlogged.
Variety Selection
When selecting kohlrabi seeds or seedlings, consider your local climate and growing conditions. Some varieties are better suited for specific regions. Choose reputable seed suppliers to ensure high-quality seeds. Both purple and green varieties are readily available from most seed suppliers.
Harvesting Techniques
Kohlrabi is best harvested when the bulb is about 2-3 inches in diameter. Harvesting at this size ensures optimal tenderness and flavor. Use a sharp knife to cut the bulb from the stem, leaving a small portion of the stem attached. Overgrown kohlrabi can become tough and woody, so it’s essential to harvest at the right time.
Pest and Disease Management
Kohlrabi can be susceptible to certain pests and diseases, such as aphids, cabbage worms, and clubroot. Implementing preventative measures, such as crop rotation and using row covers, can help to minimize these problems. Regularly inspect your plants for signs of pests or diseases. Organic pest control methods can be used to protect your plants without harming beneficial insects.
Storage and Preservation Tips
Proper storage and preservation techniques can help to extend the shelf life of kohlrabi.
Short-Term Storage
Kohlrabi can be stored in the refrigerator for several weeks. Remove the leaves before storing, as they can draw moisture from the bulb. Store kohlrabi in a plastic bag or container to prevent it from drying out.
Long-Term Preservation
Kohlrabi can be frozen for long-term storage. Blanching the kohlrabi before freezing helps to preserve its color and texture. Cut the kohlrabi into small pieces before blanching and freezing. Pickling is another option for preserving kohlrabi.
Signs of Spoilage
Discard kohlrabi if it becomes soft, mushy, or develops an unpleasant odor. Proper storage is essential to prevent spoilage.
In conclusion, while both purple and green kohlrabi share many similarities, understanding their subtle differences in appearance, taste, and nutritional value can help you make informed choices in the kitchen and garden. Whether you prefer the vibrant color of purple kohlrabi or the milder flavor of green kohlrabi, both varieties offer a delicious and nutritious addition to your diet. Experiment with both varieties to discover your personal preferences and culinary creativity.
What are the main visual differences between purple and green kohlrabi?
The most obvious difference between purple and green kohlrabi is their outer skin color. Purple kohlrabi, as the name suggests, boasts a vibrant purple or sometimes reddish-purple hue, while green kohlrabi has a pale green or whitish-green exterior. However, it’s important to note that this color difference only applies to the outer skin. The flesh inside both varieties is typically a pale yellow or white.
Beyond the skin, the size and shape of both varieties are generally quite similar. Both purple and green kohlrabi are typically round or slightly oblong bulbs with stalks and leaves protruding from the top. The leaf color is consistent across both varieties, a dark to medium green. You shouldn’t rely on leaf appearance to differentiate between them.
Does the taste of purple kohlrabi differ from green kohlrabi?
The taste difference between purple and green kohlrabi is often subtle, and some people may not even notice a difference. Generally, both varieties have a mild, slightly sweet flavor, often described as a cross between a turnip and a cabbage. However, some claim that green kohlrabi has a slightly sweeter and milder flavor compared to its purple counterpart.
Purple kohlrabi, on the other hand, may possess a slightly sharper or more pungent taste, especially when raw. This difference is often attributed to the presence of anthocyanins, the pigments responsible for the purple color. Despite this slight variation, both are delicious and can be used interchangeably in most recipes. Cooking can also mellow any perceived flavor differences.
Are there any nutritional differences between the two varieties?
Both purple and green kohlrabi are nutritious vegetables, offering a good source of vitamin C, potassium, fiber, and various other essential nutrients. However, purple kohlrabi has a slight advantage when it comes to antioxidants. The purple color is due to anthocyanins, powerful antioxidants known for their potential health benefits, such as reducing inflammation and protecting against certain diseases.
While green kohlrabi doesn’t contain anthocyanins in significant amounts, it still offers a wealth of health benefits. Both varieties are low in calories and fat, making them a healthy addition to any diet. The differences are minor, so choosing between the two should primarily be based on taste preference and availability.
How should I store purple and green kohlrabi to keep them fresh?
Proper storage is key to maintaining the freshness of both purple and green kohlrabi. The best way to store them is to remove the leaves and stalks, as these can draw moisture from the bulb, causing it to dry out. Store the bulbs unwashed in a plastic bag in the crisper drawer of your refrigerator.
Separately, you can store the leaves and stalks in a damp paper towel inside a plastic bag in the refrigerator. Kohlrabi bulbs stored this way can last for several weeks. The leaves, however, will only stay fresh for a few days. Always inspect them for any signs of spoilage before using. Discard any kohlrabi that appears slimy or has an off odor.
Can I cook purple and green kohlrabi the same way?
Yes, both purple and green kohlrabi can be cooked using the same methods. Their similar texture and flavor profiles make them highly interchangeable in recipes. You can roast them, stir-fry them, steam them, boil them, or even eat them raw in salads or slaws.
Regardless of the cooking method you choose, it’s important to peel the tough outer skin of the kohlrabi bulb before cooking. The peeled flesh can then be cut into cubes, slices, or wedges depending on your preference and the requirements of the recipe. The leaves are also edible and can be cooked like spinach or kale.
Does purple kohlrabi stain other foods when cooked?
While purple kohlrabi contains anthocyanins, the same pigments that give blueberries and red cabbage their color, it generally doesn’t stain other foods significantly when cooked. The color is more concentrated in the outer skin, which is typically peeled off before cooking.
However, if you are cooking purple kohlrabi in a liquid, such as in a soup or stew, there might be a slight tint to the broth. This tint is usually very subtle and doesn’t significantly affect the appearance of the final dish. If you are concerned about color transfer, consider steaming or roasting the purple kohlrabi separately.
Where can I find purple and green kohlrabi?
Both purple and green kohlrabi are typically available at farmers’ markets, especially during the late summer and fall seasons. Farmers’ markets often offer a wider variety of produce than grocery stores, and you’re more likely to find both types there. Local growers can also tell you more about the specific varieties they offer.
Larger grocery stores and supermarkets may also carry kohlrabi, although the availability can vary depending on the region and the time of year. Green kohlrabi is generally more common and readily available than purple kohlrabi. If you’re having trouble finding either variety, consider checking specialty produce stores or Asian markets, as kohlrabi is a popular ingredient in many Asian cuisines.
Alden Pierce is a passionate home cook and the creator of Cooking Again. He loves sharing easy recipes, practical cooking tips, and honest kitchen gear reviews to help others enjoy cooking with confidence and creativity. When he’s not in the kitchen, Alden enjoys exploring new cuisines and finding inspiration in everyday meals.