Brewing 5 gallons of kombucha is pretty easy. In fact, it turned out to be strong enough that I could’ve added another couple gallons of water to tone it down a bit.
A quick word on plastics. Spent a few hours researching any possible issues brewing kombucha in a plastic container. There’s really no reason you can’t. It’s the same with brewing beer, just be really careful not to scratch the plastic. That gives nasty bacteria a place to hideout from sanitizers. Otherwise, it’s fine. I know there might be a little bit of chemicals leached out because of the acid blah blah blah. Not really much of a concern to me.
I got my first kombucha SCOBY from Homebrew Exchange here in Portand.
Cultures for Health has a great ebook on making Kombucha, as well as a bunch of supplies you might need to get going. (I’m not affiliated with them.)