In a large plastic bowl, pound cabbage with a wooden pounder for several minutes to release its juices.
Mix salt, whey, and any seasonings into water, then pour over cabbage. Mix well.
Pack the cabbage tightly into two wide-mouth quart canning jars and add enough liquid to cover, leaving 1 inch of space at the top of the jar.
Cover the jars tightly. Keep at room temperature for a few days, and then place in cold storage.
Lids do not need to be new and bottles will not “seal” like in traditional canning. You can eat sauerkraut at that point, but it’s best after six months when the fermentation has softened the shredded cabbage. Do not open the jars until you are ready to eat the contents, as lacto-fermentation is anaerobic and is interrupted by the introduction of oxygen. You can refrigerate for a few months, however, after opened.