Chop or grate the cabbage finely or coarsely, however you prefer.
Place the sliced cabbage in a nonreactive bowl or ceramic crock alternating with the salt water as you go. This draws moisture out of the cabbage and creates the brine in which the cabbage will ferment.
Add your desired flavoring elements, fold into the cabbage, then cover the bowl with a cloth or towel to keep dust and flies away.
Over the next 24 hours, check that the brine is above the cabbage. Simply add more salt water (a ratio of 1 tablespoon sea salt mixed into 1 cup of water) if necessary.
Let the cabbage ferment in the crock and continue to check it every two days. The kraut will become tangy after a few days, at which point you can begin eating it, but it will become stronger over time.
Take it from the crock to eat as needed but leave the rest in the crock, fully submerged, to continue to develop.
Keeping it in a cool place is beneficial because it will slow the fermentation, which will preserve the kraut for longer. The volume will reduce over time, and a bloom may appear at the surface. This is simply a reaction to contact with air and can be skimmed off. If you find that the brine begins to evaporate, just add more salted water. You can continue to add fresh cabbage to this brine to ensure a constant supply.