During the bottling process oxygen inevitably makes it’s way into the bottle and is capped therefore fueling the oxidation process. This process inherently changes the flavor of the beer over time. There is also leftover oxygen that is tied up in the beer compounds that can change the flavor of your beer. This is a comlex mechanism that is not very well understood. Sounds like a potential doctoral thesis to me. 
Oh, now if someone gets all scientific with it , it wont make sense anymore ???
All I know… it works
However, if the pressure inside the bottled beer is greater than the surrounding pressure, then the bottle should not intake o2, rather it should diffuse CO2, and there should be no oxidation. Unless the brewer did not carbonate the bottles correctly, then I really can’t see how air will try to force itself into a bottle that ideal has a higher pressure than its surroundings.
I’m not saying, I’m just saying.
I know, it’s counter-intuitive that the O2 will force it’s way into the bottle and increase the pressure. But it does. 
It is a case of gas/gas osmosis, and O2 can pass into the bottle because there is a higher percentage of O2 in the atmosphere than in the bottle, assuming the membrane is actually O2 permeable. It doesn’t matter what the CO2 pressure is in the bottle, only what the relative O2 pressure is.
I’ve thought about writing such an article for a long time, but I can’t speak to the science side of things. I’m not a scientist, nor do I play one on tv. I wish beer had been a topic of consideration during science classes in high school - I would have paid a lot more attention in class.
On the other hand, I love vintage beer. One of our Hogtown Brewers club members, Jim Ritchhart, is a vintage beer fanatic. His ‘cellar’ is a large stairwell closet in his home. He is also a belgian beer fanatic and goes to Belgium at least once a year. He looks for and brings back vintage beer regularly. He has the patience to store them and then, being a generous guy, he holds occasional vintage beer tastings that rival anything held anywhere. I’ve had the privilege to attend a number of these tastings. The changes big beers can undergo over long periods of time can be truly amazing.
Yes, I said ‘can be’, it’s certainly somewhat of a crap shoot. The better the cellaring conditions (more stable, temp swings bad, cellar temps in mid-50’s-60’s) the more likely you’ll be successful. Best to have multiple examples and drink one once in a while. There can be a point where quality/flavor begins to be negatively impacted. Many of us don’t have the patience or a good space for this, but it can be amazing.
If anyone’s interested, I’d love to talk about this more, but gotta go now. In the meantime, check out this site…
Interesting that oxygen will try to permeate its way through the permeable seal of the bottle cap of a beer bottle that is of higher pressure. I am just really curious to how this works.
Then maybe dipping the cap in sealing wax for a beer one wants to keep for a long time. Or use corks.
The process is exactly the same. The only real difference between the two is that aging in bulk ensures greater uniformity that cannot be guaranteed in different bottles from the same batch.
Corks aren’t impervious to oxygen either, although the longer the cork’s contact surface with the bottle the slower the oxidation, and the wine world will tell you that a cork works by being kept wet to keep the seal (bottles stored on the side). Wax would presumably work well, assuming that you could be sure to get a full seal.
That’s an interesting point. As you note, the wine world univerally ages wine on its side to keep the cork wet. This is an area of question with vintage beer. You’ll find opinions on both sides, but it seems the majority age their beers upright (I agree with this approach). The cork does dry and degrade but over a long period before it is significant.
I’ve found that beers that are cellared for many years (10+) often (though not always) go flat. This is true for both corked & capped beers. I’ve seen examples (primarily meads) at competitions that have both a cork and are capped. There are a number of beers and wines that are waxed. Lots of approaches to dealing with the seal and potential oxidation. Oxidation in cellared beers is not necessarily a bad thing. There are positive & negative flavors that are oxidative in nature. That said, keeping oxygen away from the beer is generally a good thing. One big thing to look for in choosing beers to cellar is to go with yeast conditioned beers, and to avoid filtered or force carbonated beers.
See if this helps explain it:
http://www.av8n.com/physics/gas-laws.htm#sec-osmotic-flow
Like I said, it’s counter-intuitive, but it’s physics
;D
Think about it this way - without a hermetic seal, equilibrium must eventually be achieved. Pressure and composition will therefore eventually be equalized. This happens through co2 exiting and o2 entering until that happens.
This is a great thread. I’m going to start an “Aging beer” poll because I’m now curious what everyone else is doing. I’m not trying to steal the thunder from this thread and I agree that it’s a great idea for an article.
Osmosis…nice. ;)
I love that shirt. :)
If the partial pressure of O2 in the Atm is greater than in the beer, the O2 will go in if the cap is permeable. Sierra Nevada changed from the twist offs to a pry off with a new O2 barrier cap liner to increase shelf life a few years back.
Now, what the hell caused you to dig this old thread up? Even Jeff was still posting back then! Hope to see old Ben’s face posting again here someday - that’s for sure.
Damn! You sounded smart right there, You did! 8)
That’s kinda my thinking as well. Others will disagree though.
Oh i don’t know, I guess I was just diggin through my 2 yr old dopple bock stash, and this sounded interesting. Maybe if I submerged my aging beer in water then I wouldn’t have to worry about oxidation when aging beer. :-\
I’m glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!
When aging brews under water I always use my titanium caps