Sauerkraut — cabbage shredded, salted, and fermented by *Lactobacillus* bacteria until sour, tangy, and shelf-stable — arrived in America with German immigrants and became a staple of German-American communities from Pennsylvania to Wisconsin. The technique is identical to Korean kimchi in its basic biology (salt + vegetable + *Lactobacillus* = lactic acid fermentation) but the product is different: sauerkraut uses only cabbage and salt (no chilli, no garlic, no fish sauce). Sauerkraut on a hot dog (New York-style), on a Reuben sandwich, alongside bratwurst (AM4-02), and as a condiment with sausages is the German-American thread through American food.
Green cabbage, cored and shredded thin (2-3mm), tossed with salt (2-3% of the cabbage weight), packed tightly into a crock or jar, and pressed until the salt draws enough moisture from the cabbage to create a brine that submerges the shredded cabbage. Weighted to keep the cabbage below the brine surface. Fermented at room temperature for 1-4 weeks, during which *Lactobacillus* bacteria convert the cabbage's sugars to lactic acid, producing the characteristic sour tang. The finished sauerkraut should be tangy, crisp, and clean-tasting — not mushy, not slimy, not off-flavoured.
1) Salt ratio: 2-3% of cabbage weight. Too little and harmful bacteria may develop; too much and the *Lactobacillus* is inhibited. 2) Submerge completely — cabbage above the brine moulds. Weight it down. 3) Room temperature fermentation for 1-4 weeks. Taste daily after day 5; stop fermentation (by refrigerating) when the sourness reaches your preference. 4) Use a clean vessel — but do NOT sterilise the cabbage. The *Lactobacillus* lives on the cabbage leaves naturally; the salt creates the environment in which it thrives.
The Reuben sandwich — corned beef, Swiss cheese, sauerkraut, and Russian dressing on rye bread, grilled — is the most famous sauerkraut application in American food. The sourness of the kraut cuts through the fatty corned beef and the melted cheese. Homemade sauerkraut is a different product from canned or jarred commercial sauerkraut — the living ferment has complexity, crunch, and probiotic content that pasteurised commercial products lack.
Sandor Katz — Wild Fermentation; Luisa Weiss — Classic German Baking