Pressure Fermentation

[MichaelQld]

Hi long time brewer using old 30l barrel fermenters and airlocks with usual taps for transferring I now am using two 60l pet uni tank pressure fermenters.  To best conserve c02 the brewing process and allow the c02 help 2nd fermentation process so you don’t need to force carbonate or add priming sugar to the kegs when do close the spundy valve?

[Shamus O'Sean]

2 hours ago, MichaelQld said:

Hi long time brewer using old 30l barrel fermenters and airlocks with usual taps for transferring I now am using two 60l pet uni tank pressure fermenters.  To best conserve c02 the brewing process and allow the c02 help 2nd fermentation process so you don’t need to force carbonate or add priming sugar to the kegs when do close the spundy valve?

I reckon you should have the spundy/spunding valve set around 12psi for the whole ferment.  That keeps the pressure inside the FV and carbonates the liquid like having a keg set at 12psi for a week.

But what would I know, I must say I have not had much luck with trying to carbonate in a pressure fermenter during fermentation.  Mostly because

1. I do a long cold crash; and
2. I usually open the fermenter to add finings to my brews

The cold crash tends to drop the pressure, so I think I lose a lot of carbonation through that process.  Opening the FV is not good for maintaining pressure either.  Even though I usually push it back up to 12psi with a CO2 bottle.

Cheers and welcome to the forum.

[Aussiekraut]

10 hours ago, Shamus O'Sean said:

I reckon you should have the spundy/spunding valve set around 12psi for the whole ferment.  That keeps the pressure inside the FV and carbonates the liquid like having a keg set at 12psi for a week.

But what would I know, I must say I have not had much luck with trying to carbonate in a pressure fermenter during fermentation.  Mostly because

1. I do a long cold crash; and
2. I usually open the fermenter to add finings to my brews

The cold crash tends to drop the pressure, so I think I lose a lot of carbonation through that process.  Opening the FV is not good for maintaining pressure either.  Even though I usually push it back up to 12psi with a CO2 bottle.

Cheers and welcome to the forum.

I usually re-gas the FV after I add finings. When ramping down the temperature toward a cold crash, the pressure gradually reduces anyway, so by the time I add finings, there isn't too much left. after the finings are in, I briefly connect it to CO2 to build the pressure up again. It seems to be enough to pre-carbonate the beer quite nicely, despite the cold crash temps. It isn't fully carbed up but there is enough fizz to make the beer drinkable right away.

[MichaelQld]

Thank you both I hoping to put two brews on this weekend and will try I don’t coldcrash until I have transferred to the corny kegs