Sauerkraut s finely cut cabbage that has been fermented by various lactic acid bacteria, including Leuconostoc, Lactobacillus, and Pediococcus. It has a long shelf life and a distinctive sour flavor, both of which result from the lactic acid that forms when the bacteria ferment the sugars in the cabbage.

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.[5] The Roman writers Cato (in his De Agri Cultura) and Columella (in his De re Rustica) mentioned preserving cabbages and turnips with salt.

Sauerkraut took root mostly in Eastern European and Germanic 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 literally “sour herb” or “sour cabbage”. The names in Slavic and other East European languages are not cognate with German sauerkraut, but have similar meanings: “fermented cabbage”

-Wikipedia