Ive actually been useing babies off the same culture for a couple years now, had no idea this stuff was as complex as ive been reading. (the extent of my knowlege was its a bunch of happy critters that love sugar and tea, so being a homebrewer, it just seemed like I ought to try it, well, i like it)
Here are a few things Ive tried and came out decent.
first off, Im not sure how you guys do it, or If Im even doing it right, but it works. heres my recipie.
1. I got a scobie from a friend and bought some black tea and green tea
2. I brew a gallon of tea, with one cup un-refined cane sugar, let cool overnight
3. plop in a scobie and cover with cloth in a gallon pickle jar, I use rubber bands to keep it tight so bugs dont get in (fruit flies love the stuff)
4. let sit someplace warm and safe for about a week or two, depending on temperature, or what tea I used
5. transfer into juice bottles, about 1/4 full and top off with juice of choice and 2 tbsp cane sugar, cap and let sit for another week or two
6. enjoy, its like homemade soda, but good for you and the family.
I should mention a few things though, as for bottles, I only use swingtops when I know its gonna be drank in a week, Dont need any explosions. I regularly use rw knudsens juice in the glass jars, and I found the caps hold some pressure back to make it fizzy, but begin to vent after a point, so it never pops, and they always get fizzy (theres a constant chorus of little squeaks and hisses from the shelf)
I dont know if it helps, but I use un-refined cane sugar and have amost always had sucsess.
A couple things Ive tried...
Chi Tea has exellent results, takes longer to ferment though, gives it an awesome flavor. My personal favorite is Chi komucha with cherry cider, It rocks
Ive been tinkering with root beer, instead of adding fruit juice, I added homemade root beer mix. instead of bottling it with yeast or dry ice, I let the kombucha make it fizz. It takes a long time, and if you mix the root beer too strong it actually kills it. but its really good when it works. Ive only tried one extract though, and it was a cheap one. I plan to try it with other extracts, Ill try more natural ones and if I can get one to work with cream soda I will be in heaven.
I have a bunch of licorice root, and Im wondering If I can brew up a licorice drink, but I havent tried it yet.
just my .02