Random questions: aging and head space...

[mclamb6]

I'm thinking of brewing some small batch beers (3 gallons) that would need extended aging (RIS, sours, etc.). Two questions:

1. I have several 5 gallon bucket/Speidl fermenters--would that be too much head space/oxidation risk for a 3 gallon batch?

2. Will the temperature for aging matter? I live in Phoenix. I will have to age some of these beers through the summer. House temps are going to be high 70's at best. Will that be a problem?

 

[ColoHox]

Generally, that is too much headspace for long-term aging. But if you can maintain a layer of CO2 on top of the beer and keep good sanitation, it is definitely doable.

The higher the temperature, the faster your beer will age, for better or worse.

 

[scottballz]

I wouldn't do extended aging with that much head space. chances are the CO2 will leak out of the bucket and oxidation will take place.

 

[ColoHox]

I wouldn't do extended aging with that much head space. chances are the CO2 will leak out of the bucket and oxidation will take place.

CO2 is heavier than air, so it tends to stay put, usually in a nice layer right over the beer surface. I guess it depends on how extended this extended aging will be, as oxygen can certainly penetrate a plastic fermenter as well.

 

[scottballz]

CO2 is heavier than air, so it tends to stay put, usually in a nice layer right over the beer surface. I guess it depends on how extended this extended aging will be, as oxygen can certainly penetrate a plastic fermenter as well.

Thank you for clarifying what I was trying to get at. It all depends on your time frame here.

 

[Yooper]

CO2 is heavier than air, so it tends to stay put, usually in a nice layer right over the beer surface. I guess it depends on how extended this extended aging will be, as oxygen can certainly penetrate a plastic fermenter as well.

No, it doesn't. The "layer" of co2 is a myth, as the gases mix due to the laws of physics. During active fermentation, a ton of co2 is produced, but once fermentation stops, the Ideal Gas Law does come into play. Actually it is in play during active fermentation too, but due to the airlock and the large amount of c02 being produced, the oxygen and other gases in the headspace don't impact the beer.

I would never age a beer long term with a wide headspace, especially in plastic. Gas permeability is a factor, even through a bung and airlock, but minute amounts of oxidation can be ok.

 

[ColoHox]

No, it doesn't. The "layer" of co2 is a myth, as the gases mix due to the laws of physics. During active fermentation, a ton of co2 is produced, but once fermentation stops, the Ideal Gas Law does come into play. Actually it is in play during active fermentation too, but due to the airlock and the large amount of c02 being produced, the oxygen and other gases in the headspace don't impact the beer.

I would never age a beer long term with a wide headspace, especially in plastic. Gas permeability is a factor, even through a bung and airlock, but minute amounts of oxidation can be ok.

What kind of time frame does the gas exchange occur over? Would replacing the layer off a co2 tank help if that much headspace was your only option?

 

[Yooper]

What kind of time frame does the gas exchange occur over? Would replacing the layer off a co2 tank help if that much headspace was your only option?

It would probably help- but it does dissipate and even if you purge with 100% co2, it just isn't going to have 100% c02 in the headspace.

I'm not sure how long it would take- but it probably would be xxx/cc per day, like in this discussion of headspace and gas permeability in Better Bottles, where they studied the various closures: http://www.mocon.com/pdf/optech/Closures - Oxygen Passage Study.pdf

 

[Ramitt]

I didn't think plastic was good for long aging due to O2 permeability, unless in beers like sours were that can be beneficial. I would think 3 gallon glass carboys would be preferred.

 

[mclamb6]

An option for an aging vessel is a vacant corny keg. I'd assume this would remove the oxidation risk. What about temp?