Cut cabbage into quarters, and thinly slice into ¼ in thin, long strips.
Place all cabbage into a metal bowl, add salt and caraway seeds, and wait 5 minutes.
Mash with potato masher until cabbage starts to expel water and becomes flat and soft (about 5 minutes of mashing). Alternatively, I've also used my stand mixer with a basic paddle attachment (at a low speed) and it works well!
Once this is done, put cabbage into a quart-sized mason jar. Push down hard onto cabbage, until cabbage juice covers sauerkraut. If there is not enough liquid from the cabbage itself, add non-chlorinated water until cabbage is fully covered.
Close lid tightly and allow to sit at room temperature for at least 1 week, and up to 6 weeks for full flavor.
Note: Give at least one inch of space at top of the jar to allow for expansion from gassing from fermentation.