I first tried ginger carrots made by Amish dairy farmer who introduced me to kefir. Once I successfully started making my own kefir with his excellent milk, I carefully siphoned whey that separated from the curds during refrigeration and used it to make my own delicious ginger carrots. I later learned easier methods to get the whey: making kefir cheese or Greek yogurt.
The whey turbocharges the fermentation process, and can lead to exploding lids if not off-gassed. The recipe below is adapted from Nourishing Traditions. I recommend opening the jar over the sink in case a bubbly volcano of carrots blows the lid off. Lots of pressure in this one.