I've been fermenting my own kombucha for only a couple months now, but the other week I developed the beginnings of an ulcer. In researching ulcers I found that a certain strain of bacteria can cause ulcers, but it is not one that is supposed to be in kombucha. My dad tried my kombucha and soon after, he developed what the doctor initially thought was a urinary tract infectiona, but now thinks its something else.
Possibly unrelated, possibly related, this is the bottled kombucha from the last batch. It's been cold around here so this is about two and a half weeks old. I bottled it with non-alcoholic apple cider from the orchard down the street. Is it supposed to look like this? Now I'm scared to drink it :P