01 - Remove any damaged outer leaves from the cabbage. Cut into quarters, remove the core, and thinly slice the leaves into fine shreds using a sharp knife or mandoline.
02 - Place the sliced cabbage in a large mixing bowl and sprinkle evenly with the fine sea salt.
03 - Using clean hands or food-safe gloves, massage the salt into the cabbage vigorously for 5–10 minutes until the cabbage softens significantly and begins releasing its natural juices.
04 - If desired, add caraway seeds, grated carrot, or thinly sliced apple to the cabbage mixture and toss until evenly distributed.
05 - Transfer the cabbage and all accumulated juice into a sterilized fermentation crock or large glass jar (at least 2-quart capacity). Press down firmly with your fists or a fermentation tamper, ensuring the cabbage is completely submerged beneath its own liquid.
06 - 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 fermentation lid to allow gases to escape while keeping contaminants out.
07 - Store the vessel at room temperature (65–72°F) in a location away from direct sunlight. Allow fermentation to proceed for 7–21 days, beginning to taste after 1 week. Ferment longer for a more pronounced sourness.
08 - Once the desired level of tanginess is reached, transfer to the refrigerator to halt fermentation. Serve chilled or at room temperature as a side dish or condiment alongside sausages, pork, or roasted potatoes.