Duff Beer is a fictional alcoholic drink shown in the animated television series The Simpsons . Duff Beer is known to be Homer Simpson 's favorite drink and has a mascot known as Duffman .
While Duff Beer comes in several varieties , it is revealed on a Duff Brewery tour in `` Duffless '' that regular Duff , Duff Light , and Duff Dry are the same beer , although Homer and Barney apparently remain oblivious to the fact .