So go to the bar and do this? What does this have to do with the office?
I've never had the experience of talking to some random new people at a bar if I went alone.
The only times I actually got to socialize with new people was joining a pub-crawl meetup.
Edit: I just checked the three breweries closest to me on Google maps... They just look like restaurant dining rooms? I don't know if people are comfortable with someone at another table talking to them in a restaurant.