What's the story with "gross?"

Well, my original point was (and still is) that no native speaker calls a beer mug “Stein”, and then I got curious as to where this came from. Especially as I usually hear Americans use it; Britons not so much.
Anyway, I found this on Jimbopedia:

Ja så svinger vi på seidelen igjen. Hei! Skål!