Priming plan--sound right?

[jack13]

Been doing some reading on this message board about the relevant temperature to enter into a priming sugar calculator. It seems the primary fermentation temp is the most important, but that, even after that, CO2 in the head space can dissolve back into the beer.

So, I had a Kolsch ferment in high 50s / low 60's. I moved it to 40F chest freezer, and plan to take it out and bottle after it's been in there 2 months.

Even though I fermented at, say, 60F, should I factor in that 40F more significantly since it was for a pretty long time? So maybe enter, say, 55F in the calculator?

It's about 5.5 gallons. OG: 1.046, grav after 2 week primary: 1.011. (4.4 oz corn sugar to prime, according to tastybrew.com)

 

[catdaddy66]

From what I have read, the temp to enter is the highest it got from fermentation on to bottling day.

 

[Gavin C]

Been doing some reading on this message board about the relevant temperature to enter into a priming sugar calculator. It seems the primary fermentation temp is the most important, but that, even after that, CO2 in the head space can dissolve back into the beer.

So, I had a Kolsch ferment in high 50s / low 60's. I moved it to 40F chest freezer, and plan to take it out and bottle after it's been in there 2 months.

Even though I fermented at, say, 60F, should I factor in that 40F more significantly since it was for a pretty long time? So maybe enter, say, 55F in the calculator?

It's about 5.5 gallons. OG: 1.046, grav after 2 week primary: 1.011. (4.4 oz corn sugar to prime, according to tastybrew.com)

Think about a can of coke with lots of CO2 insuspension.

Open the can and the CO2 will come out of solution to level off with the atmoshpheric co2 %. Very very small amount. Some will be retained dependng on the temperature. Warmer it gets the more CO2 will boil off.

Chilling the can of coke will not get it to recarbonate as the coke is now exposed to atmosphere. O2 will diffuse in, nitrogen is poorly soluble and CO2 is less than 1% of the atmosphere.


If you fermented at ambient ~60F it's safe to assume the beer got to 68F after fermentation was completed (ie production of CO2 in solution). I don't like under carbed beer so I would use 70F as conservative estimate for my bottle carb calculator.

During fermentation CO2 is being added to the beer. Afterwards there is no addition so the system (given enough time) will simply equilibrate with the atmospheric partial pressure of CO2.

Better yet. I wouldn't use a cacculator at all and I'd use 5.5oz of corn sugar for a 5 gallon batch of Kolsch

If you want to explore the physics behind the loss of gasses in a liquid and what governs it, this might be of interest. Henry's Law is in effect.

[ame]https://www.youtube.com/watch?v=Wiuat7KdMmA[/ame]

 

[jack13]

Think about a can of coke with lots of CO2 insuspension.

Open the can and the CO2 will come out of solution to level off with the atmoshpheric co2 %. Very very small amount. Some will be retained dependng on the temperature. Warmer it gets the more CO2 will boil off.

Chilling the can of coke will not get it to recarbonate as the coke is now exposed to atmosphere. O2 will diffuse in, nitrogen is poorly soluble and CO2 is less than 1% of the atmosphere.


If you fermented at ambient ~60F it's safe to assume the beer got to 68F after fermentation was completed (ie production of CO2 in solution). I don't like under carbed beer so I would use 70F as conservative estimate for my bottle carb calculator.

During fermentation CO2 is being added to the beer. Afterwards there is no addition so the system (given enough time) will simply equilibrate with the atmospheric partial pressure of CO2.

Better yet. I wouldn't use a cacculator at all and I'd use 5.5oz of corn sugar for a 5 gallon batch of Kolsch

If you want to explore the physics behind the loss of gasses in a liquid and what governs it, this might be of interest. Henry's Law is in effect.

https://www.youtube.com/watch?v=Wiuat7KdMmA

Thanks for the reply--very informative all around!

I'm curious about one point, though: You wrote "Chilling the can of coke will not get it to recarbonate as the coke is now exposed to atmosphere. O2 will diffuse in, nitrogen is poorly soluble and CO2 is less than 1% of the atmosphere.", but the argument I had read was that there is a layer of CO2 above the beer, and therefore there is plenty to diffuse in when the temp is lowered. No?

 

[RM-MN]

Thanks for the reply--very informative all around!

I'm curious about one point, though: You wrote "Chilling the can of coke will not get it to recarbonate as the coke is now exposed to atmosphere. O2 will diffuse in, nitrogen is poorly soluble and CO2 is less than 1% of the atmosphere.", but the argument I had read was that there is a layer of CO2 above the beer, and therefore there is plenty to diffuse in when the temp is lowered. No?

As long as there is an airlock the gas above the beer will primarily be CO2 but the quantity will be so low as to be negligible. Ignore it or calculate how much can be dissolved back into the beer. It won't be much.

 

[Gavin C]

I had read was that there is a layer of CO2 above the beer, and therefore there is plenty to diffuse in when the temp is lowered. No?

No. That's not the case. Unfortunately it is a commonly reported phenomenon on the forum which disobeys the laws of physics.

Glad my earlier ramble was of use to you. Best of luck with your brewing.