If a beer keg is tapped and served but is then untapped before it is empty, and kept cold, does that make the beer in the keg more likely to go flat or become undesirable?
Context would be if a bar takes a keg off a line to make room for another keg, but then eventually serves the original keg again.
Soo... There are two main ways to push beer out of a keg. Carbon Dioxide and regular air. Most bars use CO2 (and Nitrogen in some cases) to push the beer out. Your regular backyard kegger uses regular air which is full of oxygen. A keg will not go bad if you take it offline as long as it was being filled with CO2 at the right pressure. (Or let's say it won't go bad for many days or weeks if properly filled with CO2). Your backyard keg with the hand pump, the beer will go stale within a day or two.
