title_body: Is there a way quantify beer flavour characteristics?
upvoted_answer: Wikipedia has an entire article on beer measurements. The main truely quantitative measure of taste I'm aware of is the International Bitterness Unit or IBU. Wikipedia has a section which describes the IBU. Of course there are other quantitative measures like alcohol by volume that while not exactly taste give some value in assessing a beer. I've also seen specific gravity reported, but this isn't very common in my experience.
  Beer Advocate provides user reviews of beers where the beers are assessed numerically based on look, smell, taste and mouthfeel on a 1 to 5 scale. Although these are based on opinion, with enough reviews a useful amount of user feedback is obtained and quantified (to two significant figures).