Kale is a non-heading, leafy form of wild cabbage that comes in a range of shapes, sizes, and colors, such as blue-green, yellow-green, white, red, or purple. Different cultivars are classified by differences in their stem length and their leaf structure, as some are flat and others are frilly. The standard Kale we usually find in the grocery store is pale to deep green with large, ruffle-edged leaves and long stems. It is hardy and fibrous when fully mature, and tender enough to be used as a raw salad green when young. The pale green stems are tough and typically removed, while the tightly curled leaves are chewy yet succulent. Depending on the variety, Kale can sometimes be spicy, other times a bit sweet, and usually slightly bitter. In general, Kale offers an earthy flavor with a nutty sweetness that is accentuated when cooked.