Kohlrabi usually means the crispy crunchy bulb with a great flavor that combines the earthy sweetness of cabbage with a bit of the sharp bite and heat of turnips and radishes, but the whole plant—bulb and its greens—is edible. Most kohlrabi bulbs are a pale green and sold without their leaves attached, but purple varieties are seen at some markets. They both have a slightly alien-looking quality about them.
How to Buy & Store Kohlrabi
I like to buy kohlrabi at farmers markets where they are often sold with their leaves still attached. There are two reasons for this: first, you know the kohlrabi is supremely fresh; and second, the leaves are delicious and can be used just like kale.
Look for small bulbs of kohlrabi—about 3 inches in diameter or less—for sweeter flavor and more tender texture. Bulbs this small will taste a lot like peeled broccoli stems. Larger kohlrabi bulbs will develop a sharper, more radish-like flavor and tend to start getting woody; although their thick and fibrous peel can be cut off to reveal the tender crunchiness within.
Although I buy kohlrabi with leaves attached whenever possible, they do need to be removed for storage (just like with beets, turnips, or carrots). Cut off the leafy stalks (you can use the leaves as you would kale or collard greens; be sure to use them with a few days) and scrub the kohlrabi bulbs clean, wrap them loosely in plastic or a paper bag, and refrigerate them until you're ready to use them.
Fresh kohlrabi will last up to several weeks in the fridge.
How to Peel Kohlrabi
It can be tempting to avoid the labor of peeling any vegetable, and in some cases it works. Not so with kohlrabi. The peel is super tough and unpleasant. Take the time to remove all of the fibrous peel to reveal the tender vegetable underneath.
You can use a vegetable peeler or, even better, a paring knife.
How to Use & Cook Kohlrabi
Kohlrabi is delicious raw. Cut it into wedges and crunch on it for snacks, use with creamy dips, or give it a simple drip or two of soy sauce.
Kohlrabi also adds bite and crunch to salads and slaws—slice thinly or shred. This Carrot Kohlrabi Slaw is popular at my house.
Kohlrabi can be chopped and added to soups or stews, or boiled and added to mashed potatoes or other mashed root vegetables to lighten them up and add bit of bite to the flavor.
Kohlrabi is a delightful surprise when roasted: it turns remarkably sweet. Peel the bulbs and cut them into wedges or chunks, toss with a bit of oil, sprinkle with salt, and roast in a hot oven until brown and tender. See a recipe for Roasted Kohlrabi here.