Force carb / aging / higher then average temps

[pjwalen]

I know these two combined topics have been covered, but I am looking for a very specific detail for a project I am working on.

I would like to age a beer in a corny keg. I know this is done frequently with great success by other brewers, but I would like to both keep this keg out of the refrigerator, and carbonate it at the same time. Here are the details.

Brew my beer, ferment it in a primary for a week, condition it in a secondary vessel for 2 weeks, then keg the beer.

At this point the beer will be cellared (in a corny keg) at 60 degrees for 2 weeks, ideally under pressure to achieve 2.6 volumes of carbonation. So the regulator will be set to 24.5 PSI (give or take).

At the end of ageing, I will want to chill the beer to 40 degrees, with the regulator set to 13 PSI. Once it is chilled, will the keg still have 2.6 volumes of carbonation, or will the change in temperature lower the vols in the beer? I guess, ultimately, will I still be going through a 3-7 days of carbonating, or will it be exactly the volumes I want the moment it is chilled?

This question applies to bottles as well, can I force carb at 60 degrees, then use a counter-pressure filler to transfer to some bottles, cap, chill, then open a bottle with a perfect 2.6 volumes?

Either way, someone please blind me with science.

Thanks,
Patrick

 

[Bobby_M]

If you look at the carb charts, it answers the first question. 2.6 volumes at 60F takes 25psi. http://ebrew.com/primarynews/ct_carbonation_chart.htm

Once that 2.6 volumes is achieved (in 2-3 weeks), you can disconnect the gas and change the temperature any which way you'd like and it will always retain the 2.6 volumes unless the seal is broken in any way. If you chill it to 40F for example, look at the chart and find the closest to 2.6 volumes. That would be 14 psi at 40F. Set your reg to 14psi, connect it to the keg and away you go. Still 2.6 volumes. If you want science, look up combined gas law or more specifically Boyle's Law http://en.wikipedia.org/wiki/Boyle's_law. Also, the key is that you are NOT applying any gas while the temp change is occurring. Carb->disconnect->chill->adjust pressure->reconnect.

You can't counterpressure fill very well with warm beer even if it's carbed. As soon as you try to cap them, they'll foam all over the place. Chill first, then counterpressure fill.

 

[pjwalen]

Thanks Bobby, this is exactly the info I was looking for. I can't thank you enough.

 

[pjwalen]

Once that 2.6 volumes is achieved (in 2-3 weeks), you can,,,

Sorry to bug you again, I was just curious if I could get a quick bit of clarification.

When I force carb. in the fridge, the beer comes out fairly well carbonated in about a week. (setting the regulator to 14psi @ 40F and waiting patiently)

The 2-3 week you mention, is that how long refrigerated beer takes as well (and I've just not noticed or cared about the less than completely carbonated beer?), or is the slower carbonation time an artifact of the warmer temperature. I.E. warmer temp beer takes longer to carbonate.