Chop or shred cabbage into thin slices. Sprinkle with sea salt.
Knead the cabbage with clean hands, or pound with a potato masher about 10 minutes, until there is enough liquid to cover.
Stuff the cabbage into a quart jar, pressing the cabbage underneath the liquid. If necessary, add a bit of water to completely cover cabbage.
Cover the jar with a tight lid, airlock lid, or coffee filter secured with a rubber band.
Culture at room temperature (60-70°F is preferred) for at least 2 weeks until desired flavor and texture are achieved. If using a tight lid, burp daily to release excess pressure.
Once the sauerkraut is finished, put a tight lid on the jar and move to cold storage. The sauerkraut's flavor will continue to develop as it ages.
