There is loads of drinking in the books. Hagrid, Professor Trelawney, Winky the House elf and Professor Slughorn are all alcoholics. The kids drink butterbeer, (which is intoxicating BTW See “Goblet of Fire”), wine, mead and firewhiskey.
I meant the kids, and there is different things about butterbeer. Some things say it contains alcohol and others say that it doesn’t make humans drunk, but it does house elfs.
I figure butterbeer is like rootbeer, but magical.