I can't remember the name of it(I'll try and update if I can find the bottle in the recycling.), but I bought a bottle of some organic ginger green tea kombucha from a local coffee shop.
I brewed up a dark, Pu-erh tea, 60 minute steep using 3 tablespoons of tea in 2 quarts of boiling water(Cooled to 170 degrees before adding tea). I then let the temp get below 80 added 3/4 cups of raw cane sugar and dumped in the mini scoby from the store bought tea along with the yeast in the bottom of the bottle. I stuck it in the pantry and waited.
Within 10 days I had an 1/4 - 1/8th of an inch scoby and a really solventy smelling tea. :P I tossed that out and thoroughly cleaned the scoby and dropped it on top of a new batch made the same way.
Time for second batch: 5 days.
Results: Nice bubbly Kombucha with a great Pu-erh earthyness and a bit of sweet and sour.
Scoby: Creamy blue/white on top, tea stained on the bottom. overall about 1/8th of an inch thick. 6 inches diameter.
Average house temperature: 76.4 degrees. Low: 74.7, High: 83.1 degrees. <---someone forgot to turn on the AC.
BTW: Long steeped Pu-erh tea is some crazy good stuff, Pu-erh tea doesn't get as tannin heavy as other teas so you don't get the bitterness associated with other blacks or even a green that's steeped to long.