[Hokerer]

Priming sugar calculators all have a dependency on temperature as different temperature worts can hold differing amounts of dissolved CO2.  Question is, if I've "cold conditioned" an ale, what temperature should I use in the calc?  For instance,  my latest fermented at 62F for two weeks, cleaned up after itself at 68F for one week, and is now cold conditioning at 48F.  What temp do I want to use when calculating priming sugar?

[morticaixavier]

48 F if that is the temperature it is at when you add the sugar and bottle. It is a function of how much residual CO2 is in solution at bottling time. or at least that is how I understand the situation

[Hokerer]

48 F if that is the temperature it is at when you add the sugar and bottle. It is a function of how much residual CO2 is in solution at bottling time. or at least that is how I understand the situation

The colder it is, the more CO2 it can hold, right?  I was wondering if having it at 68F after fermentation would have allowed most of the dissolved CO2 to go away.  Afterwards bringing it down to 48F wouldn't cause the amount of CO2 to go back up (since CO2 is no longer being generated), or would it?  Maybe the CO2 in the headspace gets somehow "re-dissolved"?  If that't the case, then how long does it need to be at the cold conditioning temp in order to get the expected amount of CO2 into it?

[alikocho]

As I understood it, the temperature relates to the temp at which you are conditioning, but I have wondered what the effect of conditioning is at room temperature and then chilling a beer.

[morticaixavier]

I am now speaking almost entirley out of my A$$ but. If there is CO2 in the headspace when you chill it than some of that CO2 will, I wouild think, redisolve into the beer. I don't know if it would be the same amount though.

[Mark G]

I'd calculate it based on 68F. After you drop the temp, the yeast are no longer producing carbon dioxide. So you're not really introducing much more into the beer, other than dissolving in from the surrounding air, and that would happen very slowly since it's not in a pressurized vessel.

[tubercle]

48 F if that is the temperature it is at when you add the sugar and bottle. It is a function of how much residual CO2 is in solution at bottling time. or at least that is how I understand the situation

 I was wondering if having it at 68F after fermentation would have allowed most of the dissolved CO2 to go away.  Afterwards bringing it down to 48F wouldn't cause the amount of CO2 to go back up (since CO2 is no longer being generated), or would it?  Maybe the CO2 in the headspace gets somehow "re-dissolved"? 

The amount of CO2 depends on the temp is right. As the temp goes up some of the CO2 will come out of solution to equalize where it wants to be. The act of chilling wont necessary put it back in - well, it might absorb some but a very little amount just from atmospheric pressure. The CO2 in the head space would need to be under positive pressure to make a difference.

 That's science as Tubercle understands it

[a10t2]

You want to use the warmest temperature the beer reached post-fermentation. In this case, that would be 68°F.

When cooling, some CO2 will return to the beer, but unless the headspace is equal to the liquid volume the effect will be less than 0.1 vol.

[morticaixavier]

I am now speaking almost entirley out of my A$$ but. If there is CO2 in the headspace when you chill it than some of that CO2 will, I wouild think, redisolve into the beer. I don't know if it would be the same amount though.

You want to use the warmest temperature the beer reached post-fermentation. In this case, that would be 68°F.

When cooling, some CO2 will return to the beer, but unless the headspace is equal to the liquid volume the effect will be less than 0.1 vol.

As I said, out of my a$$

[Hokerer]

You want to use the warmest temperature the beer reached post-fermentation. In this case, that would be 68°F.

When cooling, some CO2 will return to the beer, but unless the headspace is equal to the liquid volume the effect will be less than 0.1 vol.

That was kinda my thinking too, thanks.