My dad is wondering for a Refridgerated keg, how long domestics would keep.
About 5 minutes longer than my ETA.
I think it would depend on how many friends you have over, and if it has a good flavor.
+1. So this means long term storage is not an issue.
Canucksgirl just about has it nailed. O2 is the enemy - If you can pressurise the barrel with co2 it will last months.I have found that a 5 gal barrel once cracked to the point of loosing natural internal pressure is drinkable for 2 weeks and you can cook with the rest for another week or 2 .Slightly longer in winter slightly less in summer.Bottles are the real answer then you open what you need the rest will keep for years in sealed bottles.
The best answer I found is this:"Beer, kept at 38 degrees and pressurized with CO2, will last about four months before off flavors appear. The life of handpumped beer is significantly shorter because the introduction of oxygen to the headspace in the keg will oxygenate the beer and cause it to go bad within days. Some styles do have a longer or shorter keg life, but all should last at least 2 months as long as they are cared for properly."