After three weeks of fermenting, the sauerkraut is ready to eat. I replaced the air lock lid with a regular one and stuck the jar in the fridge. We both agree that fresh sauerkraut is miles above the canned stuff that we've bought in the past. I think that the flavors will continue to develop until we've finished it off (which won't be long). I've been meaning to start a new jar, but haven't gotten around to it with all of the Thanksgiving prep. There are so many additions that we'd like to try that we may need to start more than one.
The Wild Fermentation site says:
Add other vegetables. Grate carrots for a coleslaw-like kraut. Other vegetables I’ve added include onions, garlic, seaweed, greens, Brussels sprouts, small whole heads of cabbage, turnips, beets, and burdock roots. You can also add fruits (apples, whole or sliced, are classic), and herbs and spices (caraway seeds, dill seeds, celery seeds, and juniper berries are classic, but anything you like will work). Experiment.
I think we're going make the next batch with onions and garlic, then maybe carrots with kale and spinach, bok choy with turnips or any other veg we have ripe in the garden. Perhaps we'll eventually be brave enough to move on to other fermentation projects like pickles--or kimchi (!).