Sauerkraut
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Sauerkraut, a typical German dish, is finely sliced white cabbage fermented by various lactic acid bacteria including Leuconostoc, Lactobacillus and Pediococcus. It has good keeping qualities and a distinctive sour flavor that both result from lactic acid, which forms when the bacteria ferment sugars in the fresh cabbage. 

The word comes from the German Sauerkraut, which literally translates to sour cabbage. Sauerkraut is a prominent feature of cuisines from most of the cold regions of Europe, and it is eaten in many parts in the U.S.A. and Canada as well. A similar food is also seen in Manchuria, where it is called "suan cai" in Mandarin.

Preparation

Traditionally, the container is a stoneware crock and the seal is created with a piece of wet linen cloth, a board, and a heavy stone. This arrangement is not fully airtight and will lead to spoiled sauerkraut unless the surface of the brine is skimmed daily to remove molds and other aerobic contaminants that grow on the surface where there is contact with air. An alternative that avoids this problem is a type of ceramic jar, the Harsch crock made especially for home sauerkraut production, that has a trough around its lid. When this trough is filled with water the result is an airtight seal. Glass canning jars with clamped thread less lids can also be used. Whatever kind of container is used, it must allow the escape of fermentation gasses. Commercial-scale sauerkraut production typically employs large airtight plastic barrels.

Sauerkraut is made by a process of pickling called lacto-fermentation that is analogous to how traditional (not heat-treated) cucumber pickles are made. Fully cured sauerkraut keeps for several months in an airtight container stored at or below 15°C. Neither refrigeration nor pasteurization are required, though these treatments can prolong storage life.

No special culture of lactic acid bacteria is needed because these bacteria are already present on raw cabbage. Yeasts are also present, which cause soft sauerkraut of poor flavor when the fermentation temperature is too high.

Variations include sauerkraut prepared from whole cabbages instead of shredded strips. Sometimes other vegetables are added, such as carrots. Spices may be added; caraway and juniper berries are traditional. Sometimes wine is added. Red cabbage can be used to make sauerkraut. While this is rare in the United States, it is frequently found on the menu in Germany, where it is called "Rotkohl" or "Blaukraut". When sauerkraut is made from turnips or rutabagas, the product is called sauerrüben.

For preparation at home, the USDA recommends a greater amount of salt than is traditional, making the sauerkraut unpalatably salty unless rinsed before eating. Such rinsing removes much of the nutrient content and flavor. When traditional amounts of salt are used, temperature control is critical, because spoilage leading to food poisoning can occur if the fermentation temperature is too high. However, once made, sauerkraut is a very safe food, because its high acidity prevents spoilage. USDA also recommends pasteurizing sauerkraut for storage, though this is not necessary if the raw sauerkraut has been properly made and stored. To be safe, do not eat any sauerkraut that has a slimy or excessively soft texture, or a discoloration or off-flavor, any of which can indicate spoilage.