Exposure to light can skunk a beer pretty quickly (that’s why beer bottles are usually brown or green). So your first step to guaranteeing a delicious, fresh pint is to avoid beer that is in a glass bottle. Secondly, serving it too cold can make it bitter or even tasteless, disguising all the subtle distinctions that made you want to drink it in the first place. But too warm can make your drink taste flat and boring. If you’re trying to figure out what the best temperature is for your favorite beer, you can find handy charts online.
The last variable, oxygen, might be slightly better to focus on when you’re out drinking. “Kegs have a lower oxygen pickup during the packaging process than cans or bottles do so they tend to be the best option assuming they are stored cold once filled with beer,” Jeff Tyler said. But, as with many things, there is an exception to the rule. If the beer lines aren’t cleaned at least every biweekly, bacteria can build up. According to Tyler, “If you’re out at a random dive bar and their tables aren’t clean, chances are their draft lines aren’t either and you should stick to a can or bottle.”
If you decide to order the draft anyway and you notice a buttered popcorn flavor, don’t drink it. “This is called Diacetyl and is a dead giveaway that the lines are dirty,” Tyler said.