I started a Quora Space about specialty tea. I'm not sure why I'm mentioning that here, since it doesn't seem all that relevant to the most likely tea forum participants, but why not. Maybe the idea of what's out there for social networking channels is of interest. If anyone wanted to contribute of course that would be welcome, but why would someone, I guess.
It's there. The main idea was that they had developed their own version of groups recently, the Spaces, and I'd already been answering questions about tea anyway.
I started one about "foreign cultures" first since that seemed to fit the theme better, but although I consider culture issues and travel a bit tea is a much more active interest.
As status update goes, one week in it's going nowhere. 600 people follow the space, so in terms of "attendance" it's doing ok, but there might only be one comment so far, a person saying they thought "tea" was a slang reference to gossip.
It seems clear that people aren't on Quora to follow links out of there, even though the "Space" posts can be that, in addition to the question Answers (the site is essentially a developed version of Yahoo Answers).
As for site culture Quora is fine; not nasty, and the people seem bright (so towards the opposite extreme of Reddit, where people are still much nicer than on Twitter).
Personal interest in asking questions, answering them, or reading existing answers would seem to run its course before too long. Discussion is an option but it's less natural in that format than for FB group post commentary, or so it seems to me.
Dedicated forums, like this one, seem a more natural fit for doing a subject interest justice.