title_body: Why are some beers non-vegan?
upvoted_answer: There are two main ingredients in beer that might cause them to be unsuitable for vegans. The first one might be fairly obvious. Honey is sometimes used as a sweetener, especially in meade, but certainly in other beers.
  
  However, the main cause is a fining agent called Isinglass that is made from ground swim bladders of fish.