It's carbonated, almost...!

[clarkejw]

Hello all,
I've posted previously on a similar topic, but I hope this can be treated on its own.
I'd like some advice, and I hope I describe the situation accurately. I'm a pressure-fermenting all-grain brewer, and after a hiatus of twenty years, returned to brewing four years ago when I bought an all-rounder, and then a year later my wife bought me a Brewzilla 3.1.1.
I mainly brew ales, @ 15psi without temp control, (after ruining several brews by brewing in too hot conditions), I've started my first kviek brew today, but that's another story.
My beers for the most part are delicious. Nice colour, clear, excellent flavour, BUT they're under-carbed. In my ignorance I thought that pressure fermentation resulted in fully-carbed, ready-to-go-beer.
I keg the beer, and do oxygen-free transfers. My question is, I think it's close but I'd like to add some sugar or dextrose to the corny to finish that carbonation. How close is it? Do I assume it's half-carbonated, and add half the recommended dose, or would a third be better? I realise that there are many variables at play here, but any hints or comments however general would be very welcome.

 

[Grok]

I do pressure fermenting and have been for years, anywhere from 5~15psi, and found if you go up to about 20psi warm, it probably gets somewhere close after crash cooling, but I have settled on achieving somewhere under the serving mark and let it come up slowly under bottle gas is better than over shooting the levels and having problems pouring. You still save heaps on not buying bottle co2 and get more control up to the finish line.

 

[Antbeer]

I do pressure fermenting and have been for years, anywhere from 5~15psi, and found if you go up to about 20psi warm, it probably gets somewhere close after crash cooling, but I have settled on achieving somewhere under the serving mark and let it come up slowly under bottle gas is better than over shooting the levels and having problems pouring. You still save heaps on not buying bottle co2 and get more control up to the finish line.

Thanks for your post
I’m pressure fermenting in a Fermzilla 2 and have found my last couple of brews have been under carb’d.
Are you saying you increased the pressure to 20psi when you do the Diacetyl rest, leave it there for the days it takes for the fermentation to finish, then cold crash at 20psi, or do you let the pressure drop as it cools and contracts?

 

[livo]

O2 free, closed transfer means sanitised and purged kegs. How would you add the carbonation sugar? I guess you could dissolve it in a soda or PET bottle and use a carbonation cap to push it into the keg. You'd also need to CO2 purge the bottle and transfer hose before attaching to the keg to remain fully O2 free. Doable but is it really worth it?

The problem I've found with some of my kegs is that they need a hit of pressure to seat the lid seal O-ring. Natural carbonation was too slow and the gas leaks out leaving still flat beer, albeit with slightly higher ABV.

 

[Grok]

Thanks for your post
I’m pressure fermenting in a Fermzilla 2 and have found my last couple of brews have been under carb’d.
Are you saying you increased the pressure to 20psi when you do the Diacetyl rest, leave it there for the days it takes for the fermentation to finish, then cold crash at 20psi, or do you let the pressure drop as it cools and contracts?

Yes, if you want to try and get fully carbed naturally, then see if you can get the psi up to 20ish before cold crash, but either way the psi will drop as it cools as the co2 gets absorbed more, best to monitor it carefully with a pressure gauge so it doesn't go negative and create problems, especially with plastic fermenters, but it also depends on how cold you take it down to as well, the colder you go, the more co2 gets absorbed. I usually put the gas on it as it cools and set the pressure to positive, about 5~10psi and don't worry about it as it will only use the bottle gas if if needs it, assuming there are no leaks anywhere.