From A Raw Foods Cookbook
Use 1-4 heads of cabbages, red, white, or a mix
Remove some of the outer leaves and set aside
Cut into chunks and then process (in batches) down to quite fine. Add enough water to get the blender going well.
Put cabbage in a big bowl and mix thoroughly. If it seems dry, add some water and mix again.
Press cabbage down, as far as it will go, should not be watery, just moist.
Put saved leaves on top and press down again. Put a layer of plastic wrap over the top and press all down again. Put a weight on top that will form to shape of bowl.
Cover with a tea towel and put in a place you don't go very often, the smell gets strong during fermentation.
In 3 days check to see whether you have sauerkraut. You'll know because it will smell pickled and will be translucent. If it isn't ready leave it for another day or so.
Transfer to clean jars with tight lids and press down so no air is trapped. Use immediately or store in fridge for months and use as needed.
There is a lot of good bacteria in this!