One of the most important factors in how long does keg beer last, is how you pressurize your keg beer. Beer that is pressurized using a CO2 setup will outlast a keg being pressurized with a hand pump by months. Keg beer is not usually pasteurized, if treated improperly the shelf life will be short. The keg beer should always be cold stored and kept under pressure.
Hand pump pressurizing
This seems to be the most common way to pressurize a keg. It is also the worst way to do it when trying to keep beer fresh and extend the keg beer shelf life. If you use a hand pump to pressurize your keg beer, it will not last very long. On average a keg in this condition will only taste fresh for around 8 hours, maybe a few days depending on how well you treated the keg beer and the beer style. This isn’t usually a problem since most people who use a hand pump are just looking to serve beer for a single event or party. Just remember that when you wake up in the morning and want to top off your beer, it won’t be as good as you had hoped.
If you are lucky enough to have some kind of CO2 setup for your keg beer, then you are set! Assuming you keep the beer lines clean and the system is working properly, the keg beer can stay fresh for up to 6 months, from the date it was kegged. Realistically it’s more like 4 months, tops. Most breweries will show when it was kegged, and is a good way to know how long you could keep the keg for. Some even give you a “freshness date” to simplify things and don’t recommend you drink the beer past that date. For most avid beer drinkers this isn’t a problem, no beer lasts that long in their kegerator. If you plan to leave your beer untouched for an extended period of time, it is recommended that you disconnect the beer and gas lines while you are away.
Make sure you know How Long Does Keg Beer Last and always have the freshest beer available to drink and enjoy!