In commercial tap systems, a separate line of chilled propylene glycol is bundled with the beer lines, keeping it cool as it travels from keg to tap ... that either the pumps added too much ...

The outside air can also contain bacteria that might spoil the beer. Consequently, a keg tapped with a manual pump will only last a day. Instead, you should tap the keg using a CO2-based method ...

Beer enthusiasts across the world swear that the experience of enjoying a draft pint is better than from any can or bottle. Properly pouring a beer on tap is a critical skill for any bartender.