Blichmann beer gun and residual CO2

[PierreLo]

Hi guys,

Short question for which I have difficulty to find an answer :

I am doing pressurized fermentation at about 10-12 PSI and I am using the blichmann beer gun to transfer the beer directly to the bottle. I need to reduce the pressure to 5 PSI just before bottling to avoid excessive foaming. What is the residual CO2 in my beer ? Is it based on the 10-12 PSI or 5 PSI ?

thanks,

 

[VikeMan]

You will lose a little bit of CO2 as you fill the bottles, but most of it will remain. Use cold bottles to minimize foaming.

 

[Golddiggie]

If the beer is at 10-12psi at fermentation temperature it will be under carbonated at drinking temperature. I carbonate in fermenter (post fermentation) at either 35F or 38F and then move some to keg and can the balance. I'm not using my BeerGun to fill cans (anymore) but a counter pressure can filler (Tapcooler). The counter pressure helps control foaming and keep CO2 in the beer. With the BeerGun not doing that, you'll lose some carbonation to the transfer (as mentioned already).

If you check one of the CO2 pressure at temperature charts (there are many) you'll see how much carbonation you'll have with 10-12psi at temperature. At ferment temperatures, you'll be highly under carbonated.

Here's one chart:
https://www.glaciertanks.com/site_templates/Custom/img/beer-carbonation-chart.jpg

 

[VikeMan]

If the beer is at 10-12psi at fermentation temperature it will be under carbonated at drinking temperature.

I think @PierreLo knows that, and he's trying to figure out how much residual CO2 there will be, as an input to the bottle priming calculations.

 

[Golddiggie]

I think @PierreLo knows that, and he's trying to figure out how much residual CO2 there will be, as an input to the bottle priming calculations.

I default to "assume nothing" these days. IIRC, there are priming sugar addition calculators where you can plug in the amount of residual CO2 in a beer in order to get the correct amount of sugar to add. I stopped using priming sugar LONG ago. Ever since I shifted over to kegging my beers. Which was about a decade ago now.

A beer gun is great and all for use when you want to send someone home with some beer that you don't have already some in bottles (or cans). I wouldn't do an entire batch that way anymore (at least not anything carbonated). Using a counter pressure filler is a lot better choice.

 

[PierreLo]

I still bottle beer for now … until I purchase the whole setup to keg my beer (which should be soon enough).

I have purchased a beer gun mostly to bottle with the minimum amount of oxygen.
The thing that I have to figure out is the amount of priming sugar needed to reach adequate carbonation.
Note that I know that kegging is great and all, but I haven’t find priming and bottling so bad either.

I just need to figure out the residual CO2 to not over shoot.

Thanks for your replies guys.
Best community ever !!!