Sauerkraut

Sauerkraut is Cabbage that Lacto-fermentation has soured under salt. It is a fermented pickle, not a vinegar cucumber. NCHFP groups regular dill pickles and sauerkraut as foods fermented and cured about three weeks, during which acidity increases ¹. On the canning side, sauerkraut is listed with acid foods (pH 4.6 or below) that may use a boiling-water process when you follow a tested formula ².

Sauerkraut is the ferment. The 25-pound teaching lab is Sauerkraut (NCHFP). Seasoned napa is Kimchi, not sauerkraut.

Temperature is the quality clock #

USDA/NCHFP: store at 70° to 75°F while fermenting. At 70° to 75°F, kraut is fully fermented in about 3 to 4 weeks; at 60° to 65°F, fermentation may take 5 to 6 weeks. Below 60°F, kraut may not ferment. Above 75°F, kraut may become soft ³. Soft kraut is a quality failure tied to heat, not a reason to cut salt.

Salt is not a diet knob #

Salt draws juice so the cabbage stays under liquid, and it selects the bacteria you want. NCHFP: do not attempt sauerkraut by cutting back the salt required ¹. If juice does not cover the cabbage, their tested covering brine is 1-1/2 tablespoons of salt per quart of water, boiled and cooled ³. See Brine.

Quality note from the same page: start with firm, fresh heads, and shred and start the kraut 24 to 48 hours after harvest ³. That is freshness, not a process time you invent.

What to notice #

Cabbage must stay under juice. If you weight with a brine-filled bag, NCHFP says leave the crock until bubbling ceases. If you weight with jars, check 2 to 3 times each week and remove scum ³. Smell clean lactic sour. Taste sourness and remaining crunch; mush with a rotten smell is discarded, not canned.

Fully fermented kraut may be kept tightly covered in the refrigerator for several months, or canned from their tested hot-pack or raw-pack directions (both leave 1/2-inch Headspace) ³. Use that source’s process table; do not copy it from memory. Canning and Food safety stay in charge of the jar.