Until you drink the beer.
Despite the whole notion of "born of dates" beer doesn't really go "bad." If your beer gets infected that's one thing...But beer won't just go "off" over time. Some beers, like IPA's will not be as hoppy if they are older, but that doesn't meant they are "bad" just that the hop presence will fade. An "old' ipa will be similar in flavor to a pale ale...that doesn't mean it's bad...just different.
Beer doesn't go "bad" unless your sanitization is weak. Since nothing PATHOGENIC can exist in beer/wine/cider/mead, there should never be a reason to ever fear tasting something like this, no matter how old it is. Yeah, it may taste like crap, it may be vinegar, but NOTHING that could happen, could ever cause harm to anyone.
Noone thinks twice about drinking old wine do they?????
Beer is really no different than wine, homebrew or otherwise. Properly stored it can last and be drinkable for 100s of years.
To put it in perspective, in the Dec 07 Zymurgy Charlie Papazian reviewed bottles of homebrew going back to the first AHC competition that he had stored, and none of them went bad, some had not held up but most of them he felt were awesome...We're talking over 20 years worth of beers.
This is a great thread about one of our guys tasting 4-5 years of his stored brew.
https://www.homebrewtalk.com/f14/revisiting-my-classics-160672/
And I brewed an og 1.150, 150 IBU barleywine that I won't be opening for 5 years.
Not to mention the fact that there are vertical tasting for certain beers like Stone epic, where people collect each years beer and then sample a flight of them going back in time.
I just had this expericence not too long ago...
We tried 48 year old beer today. One was interesting and drinkable, and one was gnarly.
Mbowenze has a thread about tasting an over 100 year old beer recently. And In my history thread there's a video of the OZ and James Drink to Britain tv series where they taste a beer older than that.....one that goes back to Napoleanic times iirc.
The KEG is actually the best place to store a beer, even better than a bottle. It is both light and air tight, and if you purged it with some co2, regardless of whether or not you carbed it, that will protect it from oxidation and any microorganisms getting inside.
Beer is like wine...some of it is better with age. Especially high gravity ones.
But the best way to protect beer....put it in a keg, and hit it with some gas. Regardless of whether you carb it or not, unless the seals go.....the beer should be fine.
