Looks like you are in the US, so trademark it with the Feds. ...then start international country by country.
The Brewing Network has a whole podcast on trademarks. You might want to listen to that. http://thebrewingnetwork.com/shows/1037
Also available on iTunes if that's the way your audio rolls.
While a federal registration will protect you nationally, if you don't know whether you are going to use it, you may not want to spend the money on registering. Even if you get the registration, you will need to file an "intent to use" and prove commercial use. If you can't prove it, you will lose it.
One way to get common law rights at the state level is to just start using the name in commerce with a "TM" mark. It doesn't cost anything, but will protect you at the state level assuming someone else hasn't done the same thing or registered it with the USPTO
Trademark searches at uspto.gov are free, so you may want to start there to be sure someone else doesn't have it registered.
Best of luck. I hope it's a good name...and great beer!