If you emptied a store-bought beer into another bottle and put a cap on it, I can expect that it would go bad pretty quickly.
How is primed home-brew different? Does the CO2 carbonation process preserve it? Or is it to do with the yeast?
I am just curious. I couldn't find much on this subject.
Even non-pasteurized beer doesn't "go bad" with time, not in the sense that it spoils. It may age past its prime but it won't spoil.
If you put an alcoholic beverage into properly sanitized bottles, and it won't "go bad" or spoil.
yeah, i think the key here is the alcohol. the beer may go downhill and taste bad, but it will never really spoil in the sense that food can.
And one of the reasons a homebrew can age, or so I have heard, is that the small amount of yeast in suspension in a homebrew will continue to modify the contents of the bottle. These are live ales, and like any living organism, it changes over time.