Start by making sure that all of your tools are clean and that your mason jar is sterilized.
finely shred the cabbage using a knife or mandolin.
Place the shredded cabbage in a bowl and sprinkle with the sea salt
Using clean hands, mix the salt through the shredded cabbage and gently massage it into the cabbage. Massaging the salt encourages the cabbage to release moisture, which will become the liquid the cabbage ferments in.Massage the cabbage for 5 minutes or so, or until the cabbage becomes limp and a fair amount of moisture has been released.
Transfer your sauerkraut and all the released liquid from the bowl into the mason jar and press it down with a fork to compact it. Make sure no pieces of it are sticking to the sides of the jar.Using a piece of cheesecloth that has been folded over a couple of times (or a paper towel) to cover the top of the jar and close with an elastic band.
Place the jar somewhere warm and out of direct sunlight and leave overnight
The next day check on your sauerkraut. If it hasn't released enough moisture to cover the top of the cabbage (this is always the case for me), add 1 tsp of sea salt to 1 cup of water and add to your mason jar.Tamp the cabbage down with a spoon until it is all submerged in liquid, secure the cheesecloth (or paper towel) then put the jar away again.
Check on your sauerkraut daily to make sure it is submerged in brine and that there is no mould or scum growing on it. If there is, remove it and carry on.As the fermentation process continues, the sauerkraut with change in colour, smell and taste.The sauerkraut is done fermenting when it has reached a flavour that you like. The longer it ferments, the stronger the flavour. I start checking for taste on about day 3.
When the sauerkraut has reached a flavour you like, remove the cheesecloth, secure the lid, and place in the fridge. The sauerkraut will still continue to ferment in your fridge, just at a much slower pace.
If when checking on your sauerkraut you notice any mould or scum growing, it is still safe - just remove it from the top and continue fermenting.
The smell of the sauerkraut will change as it ferments. It will start smelling more sour, but shouldn't smell off. If your sauerkraut doesn't smell good a couple of days in a row, likely something is off with your batch. Through it out and start again.
As we are trying to provide an environment for only the beneficial bacteria to survive, not introducing any non-beneficial bacteria is very important. ALWAYS make sure that you are working with clean, fresh cabbage and that your hands and tools are clean.