# How to Calculate Priming Sugar while Bottling Lagers?

``````Primary Fermentation: 50*F/10*C       2 weeks
Diacetyl Rest:        65*F/18.3*C     2 weeks
Lager:                31*F/-0.5*C     4 weeks
``````

I am reading contradictory information regarding the amount of priming sugar to add for carbonation to a lager.

Some sources suggest using the `highest temperature` (in my case, 65*F/18.3*C) while other sources suggest using the `lowest temperature` (31*F/-0.5*C) assuming it was held "for a while", and other sources suggest using the `current temperature` as the input to calculating the total priming sugar.

For example, using the calculators from Brewer's Friend and Northern Brewer, for 2.2 volumes of CO2 for 5 gallons of beer:

``````Brewer's Friend  33*F  1.5oz  of corn sugar
Brewer's Friend  65*F  3.8oz  of corn sugar
Northern Brewer  33*F  1.57oz of corn sugar
Northern Brewer  65*F  3.5oz  of corn sugar
``````

What about the fact that when I take my carboy out of the freezer into room temperature, it takes me no less than 5 minutes to siphon it into a bottling bucket, and no less than 30 minutes to bottle 5 gallons (operating at my peak efficiency)?

Additionally, I fill 12 bottles at a time before capping them all. Not only is the bottling bucket warming at one rate, but each of the bottles are warming up at different rates based on the time they have been out.

What is relevant here? Is it "the temperature of the bottle at the moment it was sealed with a cap"?

Am I over thinking this or are these relevant issues? Should I just wait for the beer to warm up to the stable room temperature, calculate the priming sugar based on room temperature and go from there? Or, does carbon dioxide escape the solution based on a function of time and temperature, not just temperature, which would require me to leave the carboy at room temperature for some time before adding the priming sugar?