How long does beer stay fresh in the growler if unopened?
“At Iron Hill, the practice has always been to consume your growler beer within a 48-hour window. The reason is that beer is kept under pressure, free of oxygen and at a certain temperature. Once you open that tap handle and dispense beer into a glass or a growler, you are removing it from that pressurized environment. This allows carbon dioxide to escape out of the beer. That’s why those last few sips of beer from your pint glass don’t taste as carbonated as those first sips. You also expose your beer to oxygen, higher temperatures and light—all of which begin to degrade and change the flavor of your beer. Beer is bottled under a very regulated and pressurized environment, so bottled beer will keep longer than your growler of beer.”