Discard outer leaves from cabbage. Rinse under cold running water and drain. Quarter cabbage and remove cores. Shred or slice cabbage, removing any large pieces. You should have about 9 kg of cabbage.
Next, add 2kg of shredded cabbage to a clean crock. Your crock may be made of stone, glass, food grade plastic or stainless steel. Mix with 3 Ttbsp pickling salt and let sit 15 minutes for juices to flow. Press firmly on cabbage to squeeze out juices. Repeat with another 2 kg until all cabbage and salt are in crock, ensuring that the cabbage is at least 10 cm below the rim of the crock.
Following, insert a clean dinner or glass pie plate on top of the cabbage inside the crock. The plate must be slightly smaller than the crock opening, yet large enough to cover most of the shredded cabbage. To keep the plate under the brine, weigh it down with 2 or 3 clean mason jars filled with water and covered with lids. Cover the container with a clean, heavy bath towel to keep out airborne particles.