Priming/bottling temperature concerns

[ayupbrewing]

Im on to my first bottling. I have not seen a complete discussion of my concerns below so I am posting them here; if I missed it please point me in the right direction.

Thanks
Ayup!

When calculating the quantity of sugar required for priming, temperature is a factor. My question is, which temperature?

A) Beer temperature at bottling
B) Proposed beer storage/serving temperature
C) Fermentation temperature

I have read arguments for A and B but believe the correct answer to be C. This makes some sense because the amount of sugar to add needs to be adjusted for the amount of residual CO2 in the beer post fermentation.

However what does not make sense about C is;

1) What is the effect on residual CO2 of the secondary? Is it correct to assume residual CO2 is not changing?
2) What if your fermentation temperature widely varies or increases substantially towards end of fermentation?
3) Does ignoring temperature of A and B have any influence on carbonation level? ie with respect to expansion and contraction of volume of beer.

 

[Yooper]

C.

Or rather, the highest temperature the beer reached during or after fermentation.

That's because the calculators try to "guestimate" the probable amount of co2 in solution, and then use more or less sugar accordingly. Cold liquids hold more co2 in solution, while warmer liquid release more co2. To see what I mean, move a fermenter from a 55 degree area to 70 degrees. The airlock will bubble, even though fermentation is long over. Once fermentation is over, no new co2 is produced so even if you store the beer at 40 degrees in secondary, you still use the fermentation temperature- or rather, the highest temperature the beer reached after fermentation started. It's confusing.

That's one reason I hate those calculators! They also try to have you carb "to style", so a stout may be 1.6 volumes, which is flat. But most commercial bottle beers are carbed at 2.2-2.5 volumes of co2, no matter what the style is, so many people end up with undercarbed beer if they don't get the temperature guestimate correct, or the volumes of c02 correct! Or worse, they have bottle bombs because they carb their weizens to 4 volumes of c02.

I use .75 ounce to 1 ounce of corn sugar per finished gallon of beer. The .75 ounce for a lower carbed beer, and the 1 ounce for more highly carbed beers. It works every single time.

 

[billl]

C.

Or rather, the highest temperature the beer reached during or after fermentation.

+1

Gas comes out of solution much quicker than it goes in. Unless you are going to drop the temp back down and lager for weeks and weeks, you should use the highest sustained temp as an estimation of CO2.

 

[ludomonster]

I use .75 ounce to 1 ounce of corn sugar per finished gallon of beer. The .75 ounce for a lower carbed beer, and the 1 ounce for more highly carbed beers. It works every single time.

I use 4 ounces, which is pretty close to .75 oz/gal. I haven't tweaked carbonation for any of my beers. But I've been satisfied and I don't compete.

 

[ayupbrewing]

OK great, thanks everyone. I think I shall go with closer to 1oz/G since i fermented at close to 70.

Ayup!