How to Make It
Combine cabbage, salt, and caraway seeds in a large non-metal bowl, squeeze and stir together, massaging cabbage with hands until cabbage softens and wilts, and has noticeably released liquid, about 5 minutes.
Using a wooden rolling pin, wooden spoon handle, or fist, pack cabbage mixture, a little at a time, into a wide-mouth quart jar or fermenting crock. Add any remaining liquid in bowl to the jar or crock, leaving at least 2 inches of space at top of vessel.
Place outer leaves of cabbage on top of cabbage mixture. This will help keep mixture submerged, and out of contact with open air. Weigh cabbage down with glass weights, marbles, or another sanitized heavy object. Cover jar lid with cheesecloth or a coffee filter fitted with a rubber band. If using a jar lid, twist until just barely tight.
Over the next 24 hours, continue to press down on cabbage to help release liquid. The cabbage must be completely submerged underneath brine. After the first 24 hours, if the liquid has not covered cabbage, add water to just cover.
Keep sauerkraut in a cool place (65°F to 75°F), away from sunlight. If using a jar with a lid, you’ll want to “burp” mixture each day. Unscrew lid slightly to release CO2 that has developed. After 3 days, you can taste sauerkraut mixture. As it continues to ferment, the flavor will evolve. When it has reached desired flavor, fasten with a tight fitting lid, and refrigerate.
While cabbage is fermenting, you will notice foam and white scum. This is natural, and the sign of a healthy fermentation. If you notice white mold, scrape it off, and make sure cabbage is submerged in liquid. If at any time black mold begins to show, throw mixture away, and start again.