I sat farther along the bar and got my glass of beer and said: "You sure cut the clouds off them, buddy. I will say that for you." "We just opened up," the kid said. "We got to build up trade. Been in before, haven't you, mister?"
This is from a first part of "Red Wind" by Raymond Chandler.
What exactly is the meaning of the expression "cut the clouds off" in this sentence?