01 - Remove any wilted or damaged outer leaves from the cabbage. Cut into quarters, cut out the tough core, and slice the leaves into thin, uniform shreds using a sharp knife or mandoline.
02 - Place the shredded cabbage in a large mixing bowl and sprinkle the fine sea salt evenly over the top.
03 - Using clean hands or food-safe gloves, vigorously massage the salt into the cabbage for 5 to 10 minutes until the leaves soften considerably and a generous amount of natural juice is released.
04 - If desired, fold in caraway seeds, grated carrot, or thinly sliced apple and mix until evenly distributed throughout the cabbage.
05 - Transfer the cabbage and all accumulated juices into a sterilized fermentation crock or large glass jar with at least 2-liter capacity. Press down firmly using 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 a fermentation lid that allows gases to escape while keeping contaminants out.
07 - Store the vessel at room temperature between 65°F and 72°F, away from direct sunlight, for 7 to 21 days. Begin tasting after 1 week and continue fermenting until the desired level of tanginess is reached.
08 - Once the preferred flavor is achieved, transfer to the refrigerator to halt fermentation. Serve chilled or at room temperature as a side dish, condiment, or ingredient in traditional German meals.