I looked for Kombucha in Busan for a couple months, but I had no luck finding anybody who was brewing it. I finally ordered a starter from the USA and it's growing nicely. If anyone needs a starter mushroom, just send me a message with your email or phone number. I live in Gwangan and work near Seomyeon. I'm excited to finally be making Kombucha and I want others to enjoy it too!
Re: Kombucha in Busan
To be honest, I don't know where to find Kombucha in Korea.. But I can supply it from Indonesia. I think its cheaper than from US.
You can go here: http://indokombucha.wordpress.com
It's Indonesian language, but they've Google translator go make it easier to understand :)