Cold Crash and Priming

[TimFarAway]

I am cold crashing, for the first time, to 40* F now and plan on bottling tonight. Is that going to affect how I mix the priming sugar? Using corn sugar. OG was 1.069, FG for the last 3 days has been 1.016. Should I let it warm up to room temp, about 68* ? Or should I prime and bottle cold and let it warm naturally. This is a 2 gallon batch. NB priming calc says if its at 40, I should use 1oz and at 68 i should use 1.56. Why the difference? Thanks for any insight you all may have.

 

[Blitzkrieg]

The difference in sugar needed varies with temperature, from what I've learned on here it's not the temperature at which you mix in the sugar but the highest temperature that your beer reached after fermentation was complete. The idea is that this is supposed to account for any CO2 that is already in solution in your beer before priming. Since CO2 is more soluble in water at lower temperatures, you will have more risidual CO2 if you kept your beer colder. However, as soon as you let the beer warm up the CO2 that is no longer soluble will boil off and be gone forever, it doesn't come back by cooling the beer back down (like trying to recap a day old bottle of beer and hoping for carbonation). So, for example; A lager brewed cold and stored cold will need less sugar than an ale brewed warm and left to sit warm for a while afterwards.

This is how I understand the priming calculators. If I'm wrong I'm sure someone will let me know

 

[TimFarAway]

Ok, thanks. So, do I warm it up and use 1.56oz or just prime it cold with 1oz?

 

[Blitzkrieg]

Depends what temperature you let it get up to after fermentation finished, if that is 68 then go ahead and use the 1.56oz either before or after letting it get up to room temp. I personally would rack to my bottling bucket onto the measured amount of sugar while it's still cold, then mix well and bottle. This way you wont have chill haze proteins that have already dropped out re-dissolving into the beer while it warms.