Photo: luxomedia / CC BY-NC-SA 2.0
Kefir is basically some bacteria and some yeast living together in symbiotic love.
The kefir grains look a litlte bit like cauliflower florets - they're small, about 1cm across.
Put these into milk to ferment and you end up with a kind of sour drinkable yoghurt that has high levels of vitamin B12, calcium, magnesium, vitamin K2, biotin, folate, enzymes and probiotics.
