Kefir is a fermented milk product. It is kind of a cousin of yogurt. The bacteria and yeast colonies shown in the top picture are what make it all work. A good place to start to learn about Kefir is the wilipedia entry.
The colonies are also called ‘grains’. There are various sources for the grains online. I got mine from a friend a few years ago. The grains grow, so after a while you have extra which you can pass on to others. Even if you don’t pass the grains on you should remove any excess grains since the taste of the Kefir is effected by the size of the colonies. The grains colonie I use for one quart or one liter of milk is about as big as a grape.
Once you have some grains its very easy to make Kefir:
* Put the grains in a non-metalic container and add milk. I use whole milk which I heat up to almost boiling and then let cool to about room temperature. This is not required, but I prefer the taste of Kefir made with milk treated in this way.
* Put the container in a dark spot at room temperature or a little above.
* Wait about 24 hours. The resulting taste and thickness of the drink depend on time and temperature. Experiment until you find the right Kefir for you.
I have a bowl of Kefir almost every day. I like to add some sweet fruit (persimmons, bananas, cactus fruit, grapes), but I’ve also had it with just some honey.