Not to go all wikipedia-y on this thread, but ...
"A snob is a person who believes in the existence of an equation between status and human worth.[1] In other words, a snob values another person primarily on the basis of the level of social rank that such other person holds in society. This implies that a snob judges who is allowed into the snob's circle of acquaintances and friends primarily on the basis of the status of such candidate. One is consequentially highly likely to lose a snob's affection and attention soon after one has lost one's status.
The term snob is sometimes also used for a person who believe that some people are inherently inferior to him or her for any one of a variety of reasons, including real or supposed intellect, wealth, education, ancestry, power, physical strength, class, taste, beauty, nationality, fame, extreme success of a family member or friend, etc. Often this form of snobbery reflects the snob's personal attributes. For example, a common snobbery of the affluent is the belief that wealth is either the cause or result of superiority, or both.[citation needed]"
The word geek is a slang term originally used to describe odd or non-mainstream people, with different connotations ranging from "an expert or enthusiast" to "a person heavily interested in a hobby", with a general pejorative meaning of "a peculiar or otherwise dislikable person, esp[ecially] one who is perceived to be overly intellectual".[1]
Although often considered as a pejorative, the term is also often used self-referentially without malice or as a source of pride. Its meaning has evolved to connote "someone who is interested in a subect (usually intellectual or complex) for its own sake."
So - beer geek = good. Beer snob = bad.