Give liverwort a cigar. It's a kraut tamper. My Grandfather had one, but he used large ceramic crocks rather than wooden barrels for sauerkraut. After the shredded cabbage was tamped down, a round wooden lid that fit inside the crock was placed on top of the cabbage, and a stone weight was put on top of that to keep it all pressed down below the surface of the liquid as it fermented. The wooden barrels were for wine.