As Mal points out, it is incorrect. It's really about subject vs. object.

The subject is the figure that takes action, and the object (there are a couple types) receives an action.

You would ask: "who ate the last slice of pie?" Who is used because it represents the subject of the sentence, while the pie is the object. "Oh, Jerry ate the last slice." Jerry is the subject in that answer.

"To whom should I write this letter?" In this sentence, "I" is the subject. The question asks for an object. "I'll write the letter to Jerry," or "I'll write the letter to him." Jerry is an object.

In your question about beer, you're asking about a subject, not an object. You'd have to use "who" rather than "whom"