31 replies to this topic

[VirginiaBeach]

I've read that CO₂ is heavier than air and oxygen (O₂). Does this mean that if you are aging your beers undisturbed and upright then you don't need to worry about oxidation during long-term aging? Will the carbon dioxide form a protective layer between the surface of the beer and the oxygen in the head space of the bottle?I wondered this after contemplating using those oxygen absorbing caps.Thanks

[No Party JKor]

The oxygen would slowly diffuse through the layer of carbon dioxide and end up in the beer. It's not like oil and water, both gases would be mixed together, the concentration of the CO2 would just be higher in the lower part of the vessel.

[MolBasser]

Gases mix. There is no "blanket" effect with CO2.MolBasser

[ThroatwobblerMangrove]

I'm planning on aging a beer for a long time coming up - are O2 caps required? I have a bottled beer that's about 9 months old and still seems good to me.

[No Party JKor]

If you're bottle conditioning, they'll probably help more than counter pressure filling. Alternatively, you can purge the head space of the bottle with CO2 before capping.

[Jimmy James]

Nice to see at least one other person here understands this. If I had a dollar for everytime on the old board someone cited the "blanket effect" of CO2...

Gases mix. There is no "blanket" effect with CO2.MolBasser

[Kremer]

The oxygen would slowly diffuse through the layer of carbon dioxide and end up in the beer. It's not like oil and water, both gases would be mixed together, the concentration of the CO2 would just be higher in the lower part of the vessel.

+1

[stangbat]

Another +1 for the gasses mix reply. A "blanket" of CO2 provides no long term protection from oxidation.

[ThroatwobblerMangrove]

If you're bottle conditioning, they'll probably help more than counter pressure filling. Alternatively, you can purge the head space of the bottle with CO2 before capping.

hmmm - maybe I'll suck it up and get some of these. unfortunately my LHBS prices are all pretty stupid so I may end up paying way too much for them...

[MtnBrewer]

It can happen but not with such a small volume of gas.

[Thirsty]

I'm planning on aging a beer for a long time coming up - are O2 caps required? I have a bottled beer that's about 9 months old and still seems good to me.

If you have CO2 then I can assume you are kegging. If so, fill the bottles off the keg and cap on foam. The foam pushes out the headspace air, allowing to cap with nothing between the beer and cap. I also feel that the beers that benefit the most from long term storage, also can benefit a bit from oxidation. An oxidative "sherry" quality in big beers can add a nice complexity. (i.e. 1996 Samiclaus- best beer I have ever had!) I think the small beers that would have a bad off flavor from oxidation should be drank while freshest anyhow and would not make the 9 month maturation.At $4-5 per gross, the O2 caps are worth it too.

Edited by Thirsty, 14 October 2009 - 11:34 AM.

[ThroatwobblerMangrove]

If you have CO2 then I can assume you are kegging. If so, fill the bottles off the keg and cap on foam. The foam pushes out the headspace air, allowing to cap with nothing between the beer and cap. I also feel that the beers that benefit the most from long term storage, also can benefit a bit from oxidation. An oxidative "sherry" quality in big beers can add a nice complexity. I think the small beers that would have a bad off flavor from oxidation should be drank while freshest anyhow and would not make the 9 month maturation.

Actually - in this case I was going to bottle condition.

[Thirsty]

Actually - in this case I was going to bottle condition.

Do you have force carb abilities? Besides needing higher vols which make bottling off the keg difficult, I see no advantages to force carbing. It has inspired me to make a spinoff thread.

[stellarbrew]

It can happen but not with such a small volume of gas.

In the quoted disaster, a massive volume of CO2 was released suddenly from the lake. I believe that the phenomenon of that mass of CO2 hugging the ground was a transient condition, and I'd guess the effect was probably enhanced by the temperature of the CO2 cloud being colder than ambient. Over a relatively short time, I'm certain that the CO2 and the surrounding atmospheric air diffused together. In other words, you can get a blanket of CO2 to stratify under the surrounding air for a short while, given ideal conditions, but I believe that the condition is not sustainable.

[MtnBrewer]

In the quoted disaster, a massive volume of CO2 was released suddenly from the lake. I believe that the phenomenon of that mass of CO2 hugging the ground was a transient condition, and I'd guess the effect was probably enhanced by the temperature of the CO2 cloud being colder than ambient. Over a relatively short time, I'm certain that the CO2 and the surrounding atmospheric air diffused together. In other words, you can get a blanket of CO2 to stratify under the surrounding air for a short while, given ideal conditions, but I believe that the condition is not sustainable.

Agreed. I was just pointing out one possible source of the belief.

[xd_haze]

It can happen but not with such a small volume of gas.

People asphyxiate quicker than gases diffuse.

[MtnBrewer]

People asphyxiate quicker than gases diffuse.

Ok. What point are you attempting to make?

[djinkc]

Ok. What point are you attempting to make?

I guess it's OK to sleep on the first floor of my house?

[Patrick C.]

Ok. What point are you attempting to make?

The 'blanket effect' is valid in some instances?