Are we sure about that?
It refers to 1933, the year Prohibition was repealed. (The 21st Amendment abolished Prohibition on 5 December 1933.)
It took 33 steps to get from the brewmaster's office to the brewing floor.
The number of words in the brewing pledge on the back of the bottle total 33 words. ("Rolling Rock, from the glass lined tanks of Old Latrobe we tender this premium beer for your enjoyment as a tribute to your good taste. It comes from the mountain springs to you.")
It's the number of the racing horse pictured on the label.
The owner bet $33 on a horse (#33, of course) and bought the brewery with the proceeds in 1933.
There are 33 streams feeding into the reservoir from which the brewery draws its water.
Groundhog Day is the 33rd day of the year, and they make a big fuss over that holiday in Pennsylvania.
The number of letters in Rolling Rock's ingredients - water, malt, rice, hops, corn, brewer's yeast - adds up to 33.
Beer tastes best at 33 degrees. (It's just above the freezing point of water.)
33 is journalism jargon for "end of copy." (Actually 30 is the term for this, not 33.)
Rolling Rock was brewed at 33 degrees.
It's related to the highest level status (33rd degree) attained by Freemasons.
The workers at the brewery belonged to union local number 33.