cold crashing secondary... question re temp and bottling

[jimlin]

I have put my carboy (secondary with dry hops) into the fridge to chill it down for a few days to try to get it to clear a bit. I've not done that before, so typically I just rack from the bucket (primary) to bottling bucket with the previously boiled priming sugar solution. I use a calculator to figure out how much priming sugar to use, and the calculator has a temperature field. I've always just used the temp of the fermenter. If this beer is now chilled when I move it to the bottling bucket, do I need to let it warm up again before bottling? Adjust the amount of priming sugar?

[jimlin]

Is the temp to use just the temp the bottles will be stored at when carbing?

[keelanfish]

I believe the temp you should use in priming calculations is the temp at the end of fermentation. When yeast are producing CO2, the colder the liquid, the more CO2 can be absorbed. The saturation point at any given pressure decreases with temp increases. So, if you are fermenting at 55 degrees, you will have to add less priming sugar to achieve a desired level of carbonation than you would if you were fermenting at 70 degrees. Cold crashing periods don't count since CO2 isn't typically being produced at that time.

[jimlin]

Aaahhh haa!!
Thanks for that explanation.
Fermented at 67-68 the whole time so I'll go with that. Thanks again

I believe the temp you should use in priming calculations is the temp at the end of fermentation. When yeast are producing CO2, the colder the liquid, the more CO2 can be absorbed. The saturation point at any given pressure decreases with temp increases. So, if you are fermenting at 55 degrees, you will have to add less priming sugar to achieve a desired level of carbonation than you would if you were fermenting at 70 degrees. Cold crashing periods don't count since CO2 isn't typically being produced at that time.

[brewinhard]

As I understand it, the temperature at bottling time should be the actual temperature of the beer at the very point of bottling. If you cold crashed your beer for a few days then you will definitely want to let the beer warm up to room temps or so before bottling. the volumes of CO2 dissolved in suspension will change based on the temperature of the beer. I have had best results using the temperature of the beer at bottling time. In the back of Jamil's BCS there is a nomograph chart for bottling which mentions that the temperature used is the temperature of the beer at bottling time.

[jimlin]

As I understand it, the temperature at bottling time should be the actual temperature of the beer at the very point of bottling. If you cold crashed your beer for a few days then you will definitely want to let the beer warm up to room temps or so before bottling. the volumes of CO2 dissolved in suspension will change based on the temperature of the beer. I have had best results using the temperature of the beer at bottling time. In the back of Jamil's BCS there is a nomograph chart for bottling which mentions that the temperature used is the temperature of the beer at bottling time.

I'm finding more resources that suggest fermentation temp like this:
http://www.tastybrew.com/calculators/priming.html

but like you said, in JZ's BCS book, he (or Palmer as Palmer contributed to the non recipe sections) states the temp to be the temp when primed. So, does that mean the temp at the time of bottling, or the temp the bottles will be stored at when carb/conditioning? I typically store bottles in the house in the mid-high 60s.

[brewinhard]

As I understand it, it means the temps that the actual beer is at when bottling. Which makes sense to me as there would be "X" number of volumes of CO2 dissolved in suspension at that temp.

If you go by fermentation temps, then lets say I ferment at 68 deg F, then crash cool for 3 days at 40 deg F. Obviously there would be more CO2 dissolved in the beer at 40 deg than at 68 deg. That is why I have always followed the beer temp at bottling time with best results.

[jimlin]

As I understand it, it means the temps that the actual beer is at when bottling. Which makes sense to me as there would be "X" number of volumes of CO2 dissolved in suspension at that temp.

If you go by fermentation temps, then lets say I ferment at 68 deg F, then crash cool for 3 days at 40 deg F. Obviously there would be more CO2 dissolved in the beer at 40 deg than at 68 deg. That is why I have always followed the beer temp at bottling time with best results.

I ended up going with the fermentation temp. The carboy warmed up to the mid upper 50s by the time I actually siphoned to the bottling bucket.

If the chill down doesn't occur until fermentation is complete, what would be creating the additional CO2 to go into the chilled beer? I understand that the lower temp allows for more CO2 to go into solution, but isn't the CO2 being created during fermentation?

The bottles are now stored in my basement where the ambient temp is around 67.

Will post back when they are ready (assuming no bottle bombs result!)