about 1 l glass jar or anything to fit it in and leave 2.5 cm (5 inch) space on top
In advance sterilize your jar/s by placing them in cold oven, lids separately, and heating up to 120°C (250°F) for 30 minutes. Let cool completely. Or just pour boiling water into them while you're preparing your cabbage.
Keep 1-2 top leaves of the cabbage which you will use at the top later to keep things submerged.
Shred the cabbage thinly on a mandolin slicer or by hand.
In a large non-metal bowl mix in salt and spice (if using). And start working it with hand until it wilts and juice starts to come out.
By handfuls transfer into your jar/s and keep pressing down with your fist until jar is almost full and juices nicely out. Leave some space on top, now fold and add your spare leaves tightly and cover all with some water if necessary. All should be submerged and some space left for the bubbling motion.
Close the lid. Place on a plate or a bowl (in case some juice will escape) and put to rest in a dark place for 2 or more weeks (depends on the room temperature, less in summer, longer in winter).
When ready it becomes rather beige in color, the liquid cloudy with tangy sour taste and crisp)
Store in a refrigerator to stop the fermenting process.