The basic plot as well as many of the name of the brewing company are references to William Shakespeare's "Hamlet". The castle in "Hamlet" was Elsinore. The heir to Elsinore's father was murdered by her uncle, who then comes to her as a ghost. In Hamlet, the uncle's name was Claudius, and in the movie he is named Claude.
At one point, Bob says, "He saw Jedi 17 times, eh!" What isn't obvious now, is that Star Wars: Episode VI - Return of the Jedi (1983) opened in May 1983, while production of "Strange Brew" had wrapped five months earlier, in December 1982. Not only hadn't the McKenzie brothers seen "Jedi" - but they couldn't refer to it by its full title, since the "Revenge"/"Return" issue was still up in the air while they were filming.
The name of the brewery in this film is Elsinore Brewery. Max von Sydow, who played the Brewmeister in this movie, was also in the film The Seventh Seal (1957). In that film he and his squire were heading towards the village of Elsinore, but decided not to because the plague was there.
Lynne Griffin's character Pam Elsinore must have just turned 18 to inherit the company as outlined by the lawyer. But her birth date on the video game is in 1959. Her character would have been 23 when the movie was filmed in 1982. Lynne Griffin was actually 30 at the time.