01 - Peel away any wilted or damaged outer leaves from the cabbage. Cut into quarters, remove 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 evenly with the sea salt. Massage firmly with clean hands for 5 to 10 minutes, working the salt into the cabbage until it softens and releases a generous amount of liquid.
03 - If desired, fold in caraway seeds, grated carrot, or thinly sliced apple, mixing thoroughly to distribute evenly throughout the cabbage.
04 - Transfer the cabbage and all its liquid into a sterilized fermentation crock or large glass jar (at least 2-quart capacity). Press down firmly with your fists or a fermentation tamper, packing the cabbage tightly and ensuring it is completely submerged beneath its own brine.
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 debris out.
06 - Store the jar at room temperature (65–72°F) in a dark spot away from direct sunlight. Allow the cabbage to ferment for 7 to 21 days, beginning to taste after 1 week. Once the desired level of tanginess is reached, transfer to the refrigerator to halt fermentation.
07 - Enjoy chilled or at room temperature as a side dish, condiment, or as an ingredient in hearty traditional meals.