We started some kombucha at the UW farm.
It's a fermented tea. The basic instructions are: brew tea, add a lot of sugar, and lay on a round "pancake" that is a culture of both yeast and bacteria.
In two weeks it produces a sour, vinegar-y tea to drink. I happen to like it a lot, but many people don't care for kombucha.
In Russia, kombucha is revered as a folk health remedy. Many "health nuts" grow it here in the US and there are several brands of kombucha for sale in stores.
Some people (including the beloved Paul Stamets), however, do NOT like kombucha and feel it is unsafe and unwise to brew your own since a bowl covered with muslin is not much by way of sterile environment.
I used to make my own for a few months back in 2006, so I am happy to be making it again with the Farm!