### Author Topic: Determining Current CO2 Prior to Priming  (Read 368 times)

#### John Mac

• 1st Kit
• Posts: 4
##### Determining Current CO2 Prior to Priming
« on: June 10, 2019, 06:55:45 PM »
I was reading in "Brew Like A Monk" that it's best to determine the existing level of dissolved CO2 before figuring out how much priming sugar to add before bottling. Anyone know how to do this? Is there a function on Beersmith that will compute it for you? (If my Beersmith was a VCR it would still be flashing 12:00 at me) Thanks in advance!

#### kramerog

• Senior Brewmaster
• Posts: 1970
##### Re: Determining Current CO2 Prior to Priming
« Reply #1 on: June 10, 2019, 07:27:37 PM »
Beersmith like other software asks you for a temperature and then Beersmith figures out how much carbon dioxide is dissolved in the beer assuming that things are in equilibrium.  Assuming you use a bottling bucket and don't cold crash, the best temperature to use would be the current beer temperature.  Being a few degrees off doesn't make much of a difference.

#### John Mac

• 1st Kit
• Posts: 4
##### Re: Determining Current CO2 Prior to Priming
« Reply #2 on: June 10, 2019, 08:03:40 PM »
Thanks very much for the quick reply! I didn't realize that Dr Smith was already doing the math.

#### denny

• Retired with too much time on my hands
• Posts: 20884
• Noti OR [1991.4, 287.6deg] AR
##### Re: Determining Current CO2 Prior to Priming
« Reply #3 on: June 10, 2019, 09:01:34 PM »
You want to use the highest temp the beer reached.  That's because as the temp increases, dissolved CO2 comes put of solution.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

#### Josh K

• 1st Kit
• Posts: 1
##### Re: Determining Current CO2 Prior to Priming
« Reply #4 on: August 23, 2019, 12:31:00 AM »
Do you think cold crashing changes this calculation and if so how?   I recently brewed a Belgian blonde ale and wanted some more fizz so I increased my normal 4.2 oz sugar to 5 oz and kind of wish I hadn't.  I think I got more fizz then what I planned on and just wonder if it is my expectations or if my calculation was effected by the cold crash.

#### denny

• Retired with too much time on my hands
• Posts: 20884
• Noti OR [1991.4, 287.6deg] AR
##### Re: Determining Current CO2 Prior to Priming
« Reply #5 on: August 23, 2019, 02:13:11 PM »
Do you think cold crashing changes this calculation and if so how?   I recently brewed a Belgian blonde ale and wanted some more fizz so I increased my normal 4.2 oz sugar to 5 oz and kind of wish I hadn't.  I think I got more fizz then what I planned on and just wonder if it is my expectations or if my calculation was effected by the cold crash.

Nope, it shouldn't.   When the beer warms, CO2 in solution comes put of solution. Making the beer colder doesn t make the CO2 go back in.  Again, the highest temp the beer has reached is what you should use.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

#### Visor

• Brewer
• Posts: 443
##### Re: Determining Current CO2 Prior to Priming
« Reply #6 on: August 23, 2019, 04:08:46 PM »
My problem with that presumption Denny is that it doesn't take into account any fermentation that may have occurred at a lower temperature AFTER the highest temp. had been reached. Granted this scenario isn't one that is likely to be encountered often, but we are talking homebrewing and there about as many ways of doing it as there practitioners of the hobby/obsession.
Short of dumping a bunch of cash on a Zham & Nagel I wonder if there is any way to accurately measure CO2 levels and not have to rely on educated guesses.
I spent most of my money on beer, tools and guns, the rest I foolishly squandered on stupid stuff!

#### denny

• Retired with too much time on my hands
• Posts: 20884
• Noti OR [1991.4, 287.6deg] AR
##### Re: Determining Current CO2 Prior to Priming
« Reply #7 on: August 23, 2019, 04:20:18 PM »
My problem with that presumption Denny is that it doesn't take into account any fermentation that may have occurred at a lower temperature AFTER the highest temp. had been reached. Granted this scenario isn't one that is likely to be encountered often, but we are talking homebrewing and there about as many ways of doing it as there practitioners of the hobby/obsession.
Short of dumping a bunch of cash on a Zham & Nagel I wonder if there is any way to accurately measure CO2 levels and not have to rely on educated guesses.

All I can tell you is that in 550 batches I've never seen it happen. For me, at least, that means it's nothing to worry about.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

#### oginme

• Cellarman
• Posts: 97
##### Re: Determining Current CO2 Prior to Priming
« Reply #8 on: August 23, 2019, 04:24:49 PM »
One of the issues with the BeerSmith calculator within the recipe is that it relies on the carbonation sugar profile temperature (temperature entered for the sugar used) rather than the high temperature listed in the fermentation profile.  The stand alone tool is better at allowing you to enter the temperature (as Denny has stated the highest the beer has reached during fermentation) to get the correct sugar level for carbonation.

#### Dustin_J

• 1st Kit
• Posts: 6
##### Re: Determining Current CO2 Prior to Priming
« Reply #9 on: September 27, 2019, 03:43:50 AM »