Originally Posted by Clonefan94
Great information, thanks. I guess this opens another question for me then, what about storing long term in a keg then? Is there any chance of oxygen permeability through the seals at all? Or will you be safe having purged the majority of O2 from the keg?
A keg is probably THE best place for a beer long term. Or wine, too, I suppose. It's totally opaque, so no light at all. There is limited headspace- very little for 5 gallons, and if it's purged with c02, little "air" in there (but some). Just like in a wine bottle, the wine will still have a wee bit of oxygen contact over the minute headspace over time.
Beers that are aged, even in a bottle long term don't necessarily "suffer" from oxidation. Often, beers like barleywine have a tiny bit of oxidation apparent (so do some red wines aged long) and it's more of a pleasant "sherry" flavor that goes so nice with that beer style.
Many people will say things like "I left my beer in a bucket for 6 months and there are NO signs of oxidation!" Well, that's not true. Sure, the beer might taste great but of course there would be signs of oxidation however small. That's not unpleasant, necessarily. It could start as a slight "brandy" flavor in early oxidation, or a wee bit of "sherry" flavor. That's important to note. Just because someone doesn't perceive it doesn't mean it's not there to a trained beer judge.
Also, beer ages slower at cooler temperatures. A beer that may have some inadvertent oxidation will last longer at fridge temperatures or cellar temperatures than room temperature.
THE biggest flaw I see in homebrews in competition are oxidative in nature. Most homebrews I've judged display signs of oxidation (so do many commercial beers). It's just the nature of the beast. Many people think that oxidation means "cardboard" flavor. That's true, but that's only in extreme cases and I've only had "stale, musty, cardboard" one in all of the beers I've judged. Most of the time it's a bit metallic in darker beers, or a "sherry" flavor, or a bit of darkening, etc.