title_body: What can I do to prevent beer staling in a keg being pushed by air?
upvoted_answer: Avoiding agitating the beer and reducing the temperature are the two key ways to slow down the rate of staling, but really once there's air in the beer it's just a matter of time before it goes bad.
  
  Have you considered using a small CO2 charger like this - 
  
  
  
  This uses small CO2 cartridges to push the beer. The advantage being that the keg won't stale quickly since very little air is introduced.