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 - Work the salt into the cabbage vigorously with clean hands for 5 to 10 minutes, pressing and squeezing until the cabbage softens and releases enough liquid to create a brine.
04 - If desired, add caraway seeds, grated carrot, or thinly sliced apple and toss until evenly distributed throughout the cabbage mixture.
05 - Transfer the cabbage and all its released liquid into a sterilized fermentation crock or large glass jar. Press down firmly with your fists or a fermentation tamper, packing tightly to eliminate air pockets and ensure the cabbage is completely submerged in its own brine.
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 to allow gases to escape while keeping contaminants out.
07 - Store the vessel 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 the first week. When the desired level of tanginess is reached, seal and transfer to the refrigerator.
08 - Serve chilled or at room temperature as a side dish or condiment alongside sausages, roasted pork, or hearty potatoes.