I've seen many recipes that suggest juniper berries. The particular one I was referencing for this batch is from the booklet that came with my harsch crock. Here's a snippet:
You can also flavor the cabbage with spices such as juniper berries,
caraway or dill or fruits such as apples or pineapple.
I don't know about pineapple, but when I cook my kraut I usually add some apple. If you put a whole apple in your kraut for a week or two after the kraut's done it gets pretty tasty, and stays crunchy. That's something you need to try if you never have.
At any rate I'm not sure the juniper did anything, at most it may have added a little bitterness that really isn't welcome in kraut in my opinion. Live and learn, it's still a pretty tasty batch of kraut. I'm going to do a batch of cauliflower and carrots next.
You can't be a real country unless you have a beer and an airline--it helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. --Frank Zappa