I've actually already done so, and the results are, as far as I can tell, still inconclusive. Some studies find
considerable positive effect for horizontal storage,
some find none (of course, most of these are over comparatively short timescales, so I could be wrong over very long timescales). My chemistry background has more to do with fuel analysis (though I have done some food assays professionally) so what experience I have with wine/beer storage is almost entirely due to non-professional interest, so I might be mis-reading the literature. I think the question is still fairly open, and the mechanisms aren't yet well understood -- in fact, we've kind of glossed over another possible difference: even if the the interactions between water and the cork is the same for both orientations, there's a lot more than water in wine/beer, so I yield the only statement I'm actually willing to defend is that orientation likely doesn't affect cork hydration
directly.
If you wish to expand upon the literature further when you have time, I'd read it, as I do have an interest in the topic.
100% with you here. There are some similarities between wine and beer, but there are also so many differences it's hard to know. I've seen a little literature on beer storage, but most of it had to do with setting a baseline for the properties of beer over time than examining things like orientation or bottle size.
I get where you're coming from, but you're diving into a well-studied (if also myth-ridden) field. Start with a basic review of the literature (I'm on my way out and don't have time to provide right now, but there are literally entire journals devoted to preservation and storage of wine), but the evidence for wine of the benefits of horizontal storage long-term is clear and unambiguous as regards ullage, and sensory and chemical analysis. This is why it's an interesting question for beer, because beer generally has such different closures that transferring knowledge (e.g. "large bottles age better") from the wine world to the beer world is often a mistake unless the specific mechanisms are well-understood, which is particularly difficult in older beer as regards their closures because of the lack of uniform quality in corks and crown caps up until the late 90s/early 2000s. It's precisely because we're trying to avoid received knowledge from the wine world that we're asking these questions.
<3 this convo.
So IMO the whole horizontal/vertical issue boils down to cork integrity, and potential loss of elasticity which may yield faster diffusion oxygen diffusion rates of the liquid. If the cork never changed its structure, the orientation would not impact the diffusion rate of oxygen (Henry's Law in conjunction with
Fick diffusion across cork membranes).
First off, carbonated vs. non-carbonated is not an issue when discussing oxygen diffusion through the cork. As mentioned above, diffusion occurs only due to the partial pressure of the oxygen, independent of other gasses. Most of the high pressure within a carbonated bottle comes from CO2. That said, increased pressure within a beer or champagne bottle may impact the physical structure of the cork, although as far as I know this has not been studied. I'd think that the size, shape, and composition of the cork plays a far more important role.
It should also be noted that 100% humidity within the bottle does not equal the same level of saturation of a cork as direct-contact with the liquid. Water absorption during vertical storage relies upon internal pressure whereas horizontal storage utilizes direct static/capillary action of the cork to absorb liquid. There's also the question of volatility of compounds - not everything is volatile at cellar temp, and therefore would have minimal impact on the cork integrity.
Fundamentally,
vertical storage relying upon water vapor will not saturate a cork as well as horizontal storage. Absorption of water vapor by a cork
discussed here. Absorption of water, wine, etc. by cork is well-studied (it occurs in direct contact) -
here's a good article. I can provide some anecdotal evidence - my dad had a case of wine that was 10-12 years old. Some of the bottles from the case were stored horizontally in a closet, and the others were stored vertically (due to space constraints). A few Christmases ago we opened bottles of both orientation and he horizontal bottles had saturated corks whereas the corks of the vertical bottles were not saturated and were far drier overall.
That, however, doesn't mean horizontal storage is better. If you've ever had an old beer (or an old wine), you'll know that corks have a tendency to lose their elasticity, which yields a cork that is quite easy to remove from the bottle (there was a champagne-related study circulating around but nobody could seem to find the source of the data). This loss of elasticity also has a tendency to reduce the cellular matrix structure of the cork, which would yield increased oxygen diffusion (since the liquid within the bottle doesn't affect the diffusion rate, just the partial pressures of the O2).
Therefore, as
stupac2 mentioned earlier:
The critical piece of this discussion/analysis is composition and quality of the cork. Cork sourcing and manufacturing has changed over the years, and as such you will see variance within a single brewery (like Cantillon).
I'd say don't worry to much about it, unless you are trying to age very valuable or rare beers. Then, do what the manufacturer does (usually horizontal).