besides adding an awesome flavor, Horseradish is mould resistant, and having it in ther keep the greenish brown scum out of there. it never exists.. I salt once. and that is it. about 4 slices of horseradish per layer of cabbage and some dill stalks. then another lawyer of cabbage, a few more horseraddish slices, and some dill, repeat till cabbage is gone, then climb in.... and 12 days is an average... i keep it in there till it is quiet and stops bubbling... some folks around here also make it with Quince, which is another anti mold thing and has a ton of flavor.