Q: I used green tea for my brew and it's barely producing a culture. Is that fine?

A: When using only green tea it's very common for the culture to not grow as large. Your kombucha will still ferment all the same, the culture will just be thinner. The kombucha should still be done brewing after a few weeks, even if the culture isn't that large.

The reason this happens is that green tea has far less caffeine and fewer tannins, which are the two main nutrients in the tea that the culture feeds on. If you'd like to see your culture grow in a little thicker next time, I'd suggest doing a combination of green and black tea. That way you can get the flavor of the green tea in your kombucha, but your culture will get the nutrients it needs from the black tea.