Water kefir is a probiotic drink that is made with sugar, water and kefir grains. In this case, these grains don’t have anything to do with wheat or similar plants. Rather they are composed of beneficial bacteria and yeast. These grains are also not the same as dairy kefir grains. Water kefir grains feed off of sugar, so very little sugar is actually left in the finished product. The resulting product is a slightly sweet, fermented drink that contains immune boosting probiotics.