Be aware of where you are
Sure, you can get a beer in any pub in Germany - but not any beer. Many pubs offer the local brew plus a pilsener. If you order "ein Bier, bitte," the server won't ask what kind, he or she will just bring you the local stuff. In Munich it's Hefeweizen or "Helles," in Cologne, Kölsch; and in Hamburg, Astra. If you ask for a Kölsch in Munich, hold on to your lederhosen; you could get an icy stare.