I don't know what is really true but here is my understanding:
Kombucha is a fermented tea drink made as a result of a symbiotic relationship between bacteria and yeast. Not unlike Lichen, the bacteria and yeast come together via some biological/chemical attraction and form a slimy cellulose thing called a scobie. When the scobie is really big it is called a 'mother' because you can peel off layers from it and make baby scobies, which I call 'boocha babies' and give them to your friends.
So why would you want to drink this?
1) Engage in a symbiotic relationship with bacteria and yeast.
2)Add some flora and fauna to your gut.
3) Be cool.
4) I like to think about it this way: Beer is a fermented drink made from yeast. Yogurt is a fermented product made from bacteria. If you combined the power of yogurt with the power of beer....you would have KOMBUCHA.
The coolest thing about Kombucha is you can start your own boocha family basically for free. All you need is a glass jar, something that breaths to cover it, 8 organic black tea bags, 1 cup organic sugar, and approx 2 liters of water.
Brew all 8 black tea bags in 1 cup of water. Steep for 5-7 minutes and then dilute with cold water. Hot water will kill the 'boocha babies'. Add 1 cup sugar. Then add your scobie to the mix(you can buy them online or I will give you one). It might float or sink- don't worry! Then add little raw apple cider vinegar or store bought Kombucha. This gets things started. Cover with a cloth, cheesecloth, or whatever porest material you have. Then forget about it for about 2 weeks. It should be naturally carbonated. All the sugar gets digested by the yeast, so it should not taste sweet. After you are done brewing you can add flavor...by diluting the brew with whatever tea or juice want. I like to keep the finished brew with nothing in it in a glass bottle in the fridge.
Other tips:
I have been told you don't want make kombucha with other types of tea...b/c boochas LOVE black tea, and only 'like' other teas. Why not give them what they really love, instead of what they just sorta like?
But I suggest you experiment...you can't really go wrong. Just don't put anti-microbial things into your brew. (ie) honey, ginger. You can put those things in after the brew is finished, I promise.
Your 'mother' scobie can last forever, just keep adding cold tea and sugar, and some of your left over kombucha from your last batch and give away the babies.
Happy Brewing!
Marginally,
Mollie