Slice the head of cabbage in half and cut out the core. Using a mandolin or sharp knife, shred the cabbage into thin slivers.
Place the shredded cabbage in a large, wide bowl and sprinkle the salt over it. Toss to coat. Using a jar filled with something dense, like jam, pound the cabbage until the juices are released, about 10 minutes. Anything heavy and solid will work for this pounding.
Toss with caraway seeds and place in a quart-sized mason jar, pressing firmly down to tightly pack the cabbage. I recommend a small jar that fits into the mouth of the mason jar for this.
When all the cabbage is packed into the mason jar, press the smaller jar down to submerge the cabbage in its juices, and tape it into place. Cover with some cheesecloth and store on the counter for three days.
Test the sauerkraut after 3 days. If you prefer a stronger flavor, continue fermenting. I stopped at around 6 days. Place a lid on the jar and store in the refrigerator for up to several months.
Snack on it regularly. Your gut will thank you.