Alternate layers of cabbage with a sprinkling of salt, tapping or pushing down each layer with a wooden spoon or wooden potato masher. The top layer should be salt. This will not seem like enough salt, but it will give a 2 1/2 percent solution, the perfect solution for fermentation.
Boil an old dish towel in water for 5 minutes and cover the crock with it. Weight this down with a flat plate the size of the inside of the crock, weight this down with a canning jar full of water. If your using a glass as your crock, you won't need to weight it down.
Let it sit for a day. If you used fresh and tender cabbage, by the next day you should have enough brine to cover the cabbage. If you don't, make more brine by adding 1 1/2 teaspoons of salt to a cup of water and add enough to cover the cabbage.
In 2 or 3 days, white scum will form on the top. Skim this off, replace the cloth with a newly boiled one, wash the plate, and replace it all. Repeat this skimming (a 5-minute job) each day until the bubbles stop rising, or for about 2 weeks. Then your sauerkraut is done.
At this point, simply keep the cabbage below the brine with the plate, cover the crock tightly and store at 40° F to 50° F. If your basement or cellar isn't that cool, heat the sauerkraut just to simmering, pack in canning jars, seal and process in a water bath for 20 minutes for quarts, 15 minutes for pints.