Fermenting under pressure to carbonate

[jceg316]

I'm fermenting an IPA with Voss under pressure with my spunding valve set to 15psi. Will this be enough to carbonate the beer by the end of fermentation?

 

[Sadfield]

Probably not, it depends on the temperature you ferment at and desired carbonation level. 15 psi at 20C works with standard yeasts to 1.7 vols co2. You'd need around 30 psi at 30C, assuming the rapid Kveik fermentation produces the same amount of co2 in the short time it ferments.

 

[jceg316]

Thanks for that. It prompted me to look for an online force carbonation calculator which gave me the answer I was looking for. However, it seems I need to set to ~28psi for carbonation, is this too high for pressure fermenting?

 

[Sadfield]

From the limited research I've done in the past, the main concern with pressure fermenting is during the initial growth phase. As you are going to be letting the pressure build through fermentation rather than applying top pressure this shouldn't be a problem, if this article is anything to go by.

Fermenting & Dry Hopping Under Pressure - Scott Janish

Would be interesting to hear how you get on doing this with kveik. My gauge only measures up to 15 psi so i've not tried such extremes.

 

[jceg316]

From the limited research I've done in the past, the main concern with pressure fermenting is during the initial growth phase. As you are going to be letting the pressure build through fermentation rather than applying top pressure this shouldn't be a problem, if this article is anything to go by.

Fermenting & Dry Hopping Under Pressure - Scott Janish

Would be interesting to hear how you get on doing this with kveik. My gauge only measures up to 15 psi so i've not tried such extremes.

Thanks for sharing the article, I'll give it a read.

My fridge is taken up so I've left this brew outside, despite the hot weather we're having it's only 22-24C so it's probably gonna be a longer ferment than usual for kveik. There was a strangely long lag time as well. I'm making a pretty hoppy beer which will also be dry hopped so I'm not expecting much yeast character if any to come through. I'll update once it's done.

 

[foxy]

I have read the Scott Janish report before, I think he may have read the conclusions of the experimental papers. The reason the yeast reproduce quicker is because of the stress of the top pressure and the dissolved CO2 in the wort. They are dying and the reproduction is the instinct to the species clinging to life. I will be interested to see how this turns out, kviek is a strong dominant strain while it can take the temperature can it take the pressure?

 

[paul3944]

Do some yeasts fare better than others under pressure? I see there is a specific High pressure yeast (expensive to others) however I’ve seen a video where 34/70 produced a clean looking pilsner style under pressure.

 

[foxy]

Do some yeasts fare better than others under pressure? I see there is a specific High pressure yeast (expensive to others) however I’ve seen a video where 34/70 produced a clean looking pilsner style under pressure.

Yes WLP925, a lager yeast, still recommended at 15 PSI, ale yeasts don't perform well under pressure. You can make a pseudo lager or an AIPA using a neutral yeast reducing any esters and forwarding more hop flavour. But you can do that without pressure, (the AIPA), closed system fermentation is more for oxygen elimination during transfers and naturally carbing the beer.