Sauerkraut is the German name for finely shredded white cabbage fermented in its own juices.

This ancient preservation method is based on lactic acid fermentation process, caused by the natural lactic acid bacteria reacting with the sugar in the cabbage. The sugar turns into lactic acid, preserving the cabbage and giving it the characteristic freshly-sour flavour.

Sauerkraut is prepared by tossing the shredded cabbage with salt or pounding it with a wooden pounder or pestle until some juice is drawn out. The cabbage is layered together with salt in a clean container. A weight is placed on top so that the juices accumulating inside the container will entirely cover the cabbage.

To speed up the lactic acid fermentation process, acidic components like whey or small pieces of rye bread crust may be added to the cabbage mixture. The mixture is left to ferment for about 5 to 7 weeks, at a temperature cool enough to prevent it from spoiling. Creating an acidic environment, the lactic acid inhibits the forming of any less desirable micro-organisms inside the container. It should be noted that in some countries sauerkraut is sold pasteurised or ready-cooked, which kills the gut-protecting microbes and lactobacilli, reducing sauerkraut's beneficial qualities.

Sauerkraut may be served either raw, cooked or baked. Apples, onion, smoked or salted pork, bacon, various sausages and beer go well together with sauerkraut. In Germany, sauerkraut is most often served baked or sautéed in stock or other liquid. As a matter of fact, when living in Southern Germany, I found it almost impossible to find raw, unpasteurised and uncooked sauerkraut in stores and market places, especially outside the winter months, whereas here in Finland (and some other Nordic or Eastern European countries) it is plentifully available year-round.

Also many other vegetables, like mushrooms, cucumbers, tomatoes, onions, snow peas, beans, zucchinis, pumpkins, carrots, radishes, swedes, celeriacs, turnips, parsnips and beetroots, can be preserved using the lactic acid fermentation process. Spices or herbs, like shredded carrot, garlic, horseradish, caraway seeds, juniper berries, mustard seeds, dill, allspice, clove, coriander, bay leaves, tarragon, savory, blackcurrant or raspberry leaves, etc, may be added to the vegetable mixture to season it.

Fermenting preserves the minerals and vitamins in the food, even increasing the amount of certain vitamins. Fermented products also contain many biologically active compounds beneficial to human digestion, among other things.