how long will a keg stay fresh
As days go past the freshness reduces. In general, the fresher your keg draft beer is, the better it tastes. Keg beer will remain fresh if dispensing with CO2, while maintaining the proper temperature and pressure: For non-pasteurized draft beer about 45-60 days. For pasteurized draft beer about 90-120 days. When dispensing keg beer with a party pump (air), any draft beer will remain fresh for no more than 8-12 hours.
Dear Michael, By all accounts, if your kegerator's lines are clean and the kegerator is working properly, you can keep a keg of beer staying fresh for up to 6 months. 4 months is more likely. If you have to leave your home bar for a while, it is recommended to disconnect your beer and gas lines while you are gone.