Sauerkraut is finely cut raw cabbage that has been fermented by various lactic acid bacteria. It has a long shelf life and a distinctive sour flavor, both of which result from the lactic acid formed when the bacteria ferment the sugars in the cabbage leaves.

Cabbage, comprising several cultivars of Brassica oleracea, is a leafy green, red (purple), or white biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage, and belongs to the "cole crops" or brassicas, meaning it is closely related to broccoli and cauliflower ; Brussels sprouts ; and Savoy cabbage.