In this video, Samuel Merritt from Chow.com shows us how to identify off falvors in beer. These can be very subtle or very noticeable. Look out for a flavors that taste like, movie popcorn, artificial flavors and cooked corn flavors. You also should smell your beer, if it smells like wet cardboard you shouldn't be drinking it. Beer manufacturers don't mean for these things to show through in a beer, but every once in a while you can find any number of these things in a beer. Just make sure to taste it and smell it and you should be having a great beer!