Water kefir is a probiotic fizzy drink you make by adding water kefir grains to sugar water. They aren’t really grains as such, but also symbiotic cultures of bacteria and yeast that grow together in a coating of dextran. It tastes slightly sweet and can be used as a base for adding all kinds of flavour. It doesn’t have as many bioactive molecules as milk kefir, but is great if you don’t do dairy. Many of the microbes are thought to have probiotic properties (beneficial in terms of health); there are a mixture of yeasts, lactic acid bacteria and acetic acid bacteria. When we make water kefir, we provide sugar as an energy source for the microbes so that they can grow and multiply. In the process they will make carbon dioxide, a tiny amount of alcohol, lactic and acetic acids. You will end up with a fizzy, low-sugar drink full of probiotics that is a fabulous base for flavouring or you can drink it just as it is.