6. Guinness

Guinness is everyone’s favorite stout beer and has long been praised for its smoothness as a stout. Many drinkers swear by Guinness and won’t touch a drop of anything else. Guinness might not be the healthiest choice, though, for reasons you may not suspect. Apparently, Guinness contains isinglass, an ingredient derived from fish bladders. So, next time you take a sip of the richly dark brew, think about whether or not it pairs well with, well, fish.