Sauerkraut

Sauerkraut (; , "sour cabbage") is finely cut raw cabbage that has been fermented by various lactic acid bacteria. It has a long shelf life and a distinctive sour flavour, both of which result from the lactic acid formed when the bacteria ferment the sugars in the cabbage leaves. It is one of the best known national dishes in Germany.
Overview and history.
Fermented foods have a long history in many cultures, with sauerkraut being one of the most well-known instances of traditional fermented moist cabbage side dishes. The Roman writers Cato (in his "De Agri Cultura") and Columella (in his "De re Rustica") mentioned preserving cabbages and turnips with salt.
Although "sauerkraut" is a German word, the dish did not originate in Germany, as fermenting cabbage as Suan cai was already practised back in the days of the building of the Great Wall of China, and the practice was likely transmitted from China to Europe by the Tartars. It then took root mostly in Central and Eastern European cuisines, but also in other countries including the Netherlands, where it is known as "zuurkool", and France, where the name became "choucroute". The English name is borrowed from German where it means "sour cabbage". The names in Slavic and other Central and Eastern European languages have similar meanings with the German word: "fermented cabbage" (, , , , , , ) or "sour cabbage" (, , , , , , , , , , , , , "kisla kapusta").
Before frozen foods, refrigeration, and cheap transport from warmer areas became readily available in northern, central and eastern Europe, sauerkraut – like other preserved foods – provided a source of nutrients during the winter. Captain James Cook always took a store of sauerkraut on his sea voyages, since experience had taught him it prevented scurvy.
The word "Kraut", derived from this food, is a derogatory term for the German people. During World War I, due to concerns the American public would reject a product with a German name, American sauerkraut makers relabeled their product as "Liberty Cabbage" for the duration of the war.
Production.
Sauerkraut is made by a process of pickling called lactic acid fermentation that is analogous to how traditional (not heat-treated) pickled cucumbers and kimchi are made. The cabbage is finely shredded, layered with salt, and left to ferment. Fully cured sauerkraut keeps for several months in an airtight container stored at 15 °C (60 °F) or below. Neither refrigeration nor pasteurization is required, although these treatments prolong storage life.
Fermentation by lactobacilli is introduced naturally, as these air-borne bacteria culture on raw cabbage leaves where they grow. Yeasts also are present, and may yield soft sauerkraut of poor flavor when the fermentation temperature is too high. The fermentation process has three phases, collectively sometimes referred to as population dynamics. In the first phase, anaerobic bacteria such as "Klebsiella" and "Enterobacter" lead the fermentation, and begin producing an acidic environment that favors later bacteria. The second phase starts as the acid levels become too high for many bacteria, and "Leuconostoc mesenteroides" and other "Leuconostoc" species take dominance. In the third phase, various "Lactobacillus" species, including "L. brevis" and "L. plantarum", ferment any remaining sugars, further lowering the pH. Properly cured sauerkraut is sufficiently acidic to prevent a favorable environment for the growth of "Clostridium botulinum", the toxins of which cause botulism.
A 2004 genomic study found an unexpectedly large diversity of lactic acid bacteria in sauerkraut, and that previous studies had oversimplified this diversity. "Weissella" was found to be a major organism in the initial, heterofermentative stage, up to day 7. It was also found that "Lactobacillus brevis" and "Pediococcus pentosaceus" had smaller population numbers in the first 14 days than previous studies had reported.
The Dutch sauerkraut industry found that inoculating a new batch of sauerkraut with an old batch resulted in an excessively sour product. This sourdough process is known as "backslopping" or "inoculum enrichment"; when used in making sauerkraut, first- and second-stage population dynamics, important to developing flavor, are bypassed. This is due primarily to the greater initial activity of species "L. plantarum".
Regional varieties.
In Azerbaijani, Belarusian, Polish, Russian, Moravian, Baltic states and Ukrainian cuisine, chopped cabbage is often pickled together with shredded carrots. Other ingredients may include caraway seeds, whole or quartered apples for additional flavor or cranberry for flavor and better keeping (the benzoic acid in cranberries is a common preservative). Bell peppers and beets are added in some recipes for colour. The resulting sauerkraut salad is typically served cold, as "zakuski" or a side dish. A home made type of very mild sauerkraut is available, where white cabbage is pickled with salt in a refrigerator for only three to seven days. This process results in very little lactic acid production. Sometimes in Russia the double fermentation is used, with the initial step producing an exceptionally sour product, which is then "corrected" by adding 30-50% more fresh cabbage and fermenting the mix again. The flavor additives like apples, beets, cranberries and sometimes even watermelons are usually introduced at this step.
Sauerkraut may be used as a filling for Polish "pierogi", Ukrainian "varenyky", Russian "pirogi" and "pirozhki". Sauerkraut is also the central ingredient in traditional soups, such as "shchi" (a national dish of Russia), "kwaśnica" (Poland), "kapustnica" (Slovakia), and "zelňačka" (Czech Republic resp. Moravian). It is an ingredient of Polish "bigos" (a hunter's stew).
In Germany, cooked sauerkraut is often flavored with juniper berries or caraway seeds; apples and white wine are added in popular variations. Traditionally it is served warm, with pork (e.g., "eisbein", "schweinshaxe", "Kassler") or sausages (smoked or fried sausages, "Frankfurter Würstchen", Vienna sausages, black pudding), accompanied typically by roasted or steamed potatoes or dumplings ("knödel" or "schupfnudel"). Similar recipes are common in other Central European cuisines. The Czech national dish "vepřo knedlo zelo" consists of roast pork with "knedliky" and sauerkraut.
In France, sauerkraut is the main ingredient of the Alsatian meal "choucroute garnie" (French for "dressed sauerkraut"), sauerkraut with sausages (Strasbourg sausages, smoked Morteau or Montbéliard sausages), charcuterie (bacon, ham, etc.), and often potatoes.
In Chile is called "chucrut" and is a common topping for sandwiches and hotdogs, specially for completos.
Sauerkraut, along with pork, is eaten traditionally in Pennsylvania on New Year's Day. The tradition, started by the Pennsylvania Dutch, is thought to bring good luck for the upcoming year. Sauerkraut is also used in American cuisine as a condiment upon various foods, such as sandwiches and hot dogs. In Maryland, particularly in Baltimore and on the Eastern Shore, sauerkraut is a traditional accompaniment for the Thanksgiving turkey.
Health effects.
Benefits.
Many health benefits have been claimed for sauerkraut:
Disadvantages.
Excessive consumption of sauerkraut may lead to bloating and flatulence due to the trisaccharide raffinose, which the human small intestine cannot break down. This does not negatively affect long-term health, although it might be uncomfortable. Additionally, sauerkraut has a very high content of sodium.
Scientific discovery.
One of the early scientists who was involved in identifying the biology and function of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), Philippe Horvath, focused on the genetics of a lactic-acid bacterium used in the production of sauerkraut.
Similar foods.
Many other vegetables are preserved by a similar process: