Water Kefir. I suppose about now you’re wondering what kefir is. Kefir is a natural probiotic and with it, you can make your own lifetime supply of healthy, bacteria friendly probiotic using only water, sugar and something for flavor such as a few raisins. Lifetime is no exaggeration because the kefir grains multiply and you will soon have plenty to share with friends and family. Water kefir and dairy kefir use two different kinds of grains and are not interchangeable. For those of you who are sensitive to dairy, water kefir is the answer. What you end up with is a delicious drink and if you bottle it, it will become carbonated as the bacteria continue to work. So, get started.