The plate trick!
While fermenting, the shredded cabbage must be kept below the surface of the brine formed by the salt and liquid from the pounded cabbage. Bubbles will form and must escape. I chose a dinner plate just a little smaller than the diameter of the crock. The small shreds of cabbage you can see above the plate will be removed with a slotted spoon. Tip the plate to one side to make sure no air is trapped under it.
July 25, 2012