01 - Remove any damaged outer leaves from the cabbage. Cut into quarters, remove the tough core, and thinly slice the leaves into fine shreds using a sharp knife or mandoline.
02 - Place the shredded cabbage in a large mixing bowl and sprinkle evenly with the fine sea salt. Massage the salt into the cabbage vigorously for 5 to 10 minutes, working until the cabbage softens and releases a generous amount of natural juice.
03 - If desired, fold in caraway seeds, grated carrot, or thinly sliced apple and mix until evenly distributed throughout the cabbage.
04 - Transfer the cabbage and all accumulated juice into a sterilized fermentation crock or large glass jar with at least a 2-liter capacity. Press down firmly using your fists or a fermentation tamper, ensuring the cabbage is completely submerged beneath its own liquid.
05 - Place a fermentation weight or a clean smaller jar filled with water on top of the cabbage to keep it fully submerged. Cover the vessel with a breathable cloth or a fermentation lid that allows gases to escape while keeping contaminants out.
06 - Store the jar at room temperature (65–72°F) in a spot away from direct sunlight. Allow fermentation to proceed for 7 to 21 days, beginning to taste after the first week. Once the desired level of tanginess is reached, transfer to the refrigerator to halt fermentation.
07 - Serve chilled or at room temperature as a side dish, condiment, or as an ingredient in hearty traditional preparations.