Barrel Spoilage or Lack Thereof

[relaxiamadoctor]

If any of you happen not to be drunk yet, I got some Bill Nye shit for that ass. It is generally accepted that our atmosphere contains 'round about 78% oxygen which I don't imagine changes much inside any given barrel. So why, then, does the process of oxidation which, given enough time, both mellows and subsequently "spoils" a spirit once uncorked - even one left relatively undisturbed - not have the same effect on said spirit while in a barrel.

The best I can figure is oxidation of such volume to the point of spoilage takes substantially longer than for the same in 750ml and when dumped, assuming the majority remains unoxidized, blending alleviates undesirable atributes. However, one particular wrench in this equation as I see it is how many whiskies - Willett C-Barrels for example - spend very lengthy periods of time in a barrel and still have significant need to unwind. Logic says to me, based upon the length of time it takes for a bottle to slide, the volume of oxidized spirit could be low enough to hide after 10 years, though 20 years of exposure with summer heat turning turning it over via convection currents and evaportion increasing surface area, the resultant spirit should be at least very mellow in the way a properly aired spirit should, and at most totally spoiled. Yet another example is wine. If I open a bottle of wine and, for some reason recork it, it ain't no good after only a few days yet many wines spend several years in a barrel.

Maybe I'm rambling in circles thought I'd still like to hear your thoughts.

[flahute]

While in barrel, it's still interacting with the wood and taking on flavor characteristics. I'm guessing also that oxygen molecule exchanges are slow to occur through the wood. In bottle it's basically inert until oxygen is introduced via opening and pouring. The more air space in the bottle from subsequent pours, the more fresh oxygen gets introduced.

[Kpiz]

I think atmospheric oxygen is significantly lower than 78%. Though that's probably beside the point.

In addition to what Flahute said, I would think that the evaporating molecules create somewhat of a barrier between the air inside the barrel (in the headspace) and remaining liquid in the barrel.

[tanstaafl2]

Oxygen is more like 21%. It is Nitrogen that is closer to 78%. 78% oxygen would be, umm, explosive...

A lot of people think the air we breath is all or mostly oxygen!

http://teachertech.rice.edu/Participants/louviere/comp.html

[B.B. Babington]

if ya search the forum you'll find lots of discussion about oxidation.

Is oxidation a bad thing or good thing?

Loss of congeners is bad thing, to me, but lots of folks prefer airing their glass before sip.

Wine is whole different thing.

[relaxiamadoctor]

Oxygen is more like 21%. It is Nitrogen that is closer to 78%. 78% oxygen would be, umm, explosive...

A lot of people think the air we breath is all or mostly oxygen!

http://teachertech.rice.edu/Participants/louviere/comp.html

You are correct. I did not bother to fact-check and confused the two.

[relaxiamadoctor]

I think atmospheric oxygen is significantly lower than 78%. Though that's probably beside the point.

In addition to what Flahute said, I would think that the evaporating molecules create somewhat of a barrier between the air inside the barrel (in the headspace) and remaining liquid in the barrel.

I like this answer. It makes sense evaporation would create a pressure differential in a well made barrel. Still, though, I'd be surprised if once in a while a barrel didn't go flat.

[Paddy]

Alcohol doesn't go bad, so the higher the proof of a spirit... I'm not drunk enough to continue, yet!

[Quantum]

There is air space in a barrel, but it is not exactly well ventilated. Stick a hose inside a freshly opened and try to breathe through it.

[Richnimrod]

There is air space in a barrel, but it is not exactly well ventilated. Stick a hose inside a freshly opened and try to breathe through it.

CAUTION: DON'T DO THAT!!!!

Serious health hazard. A small whiff should be enough to understand the point being made.