My coworkers love craft drinks and we always head to the pub every week. Have alcohol on hand, spirits and beer, in our office right next to our desks. It's very much a part of the culture.
It was really hard for me at first. I told everyone I had eliminated it from my diet to lose some weight. And after a few months I did lose a ton of weight after I stopped drinking. Then I said I would just keep it going because it felt so good.
Eventually I came out to my boss and a few coworkers as an alcoholic. By then, everyone had gotten the idea that i didn't drink and it was really no big deal, relatively speaking. Those first few months going to the pub and pretending I didn't care were brutal. Absolutely brutal. It killed me to be sitting there while everyone was drinking.
In hindsight, I wish I had just told my boss and coworkers as soon as I felt stable/comfortable with the thought. If they can't accept it, it's their problem.