Fermenting under pressure

Red Lion Brewing Company · Friday at 6:50 PM

Hey, kids! Does anyone have any information regarding fermenting under pressure effecting stuck fermentation? I've been brewing for more than 20 years, and just started playing around with this technique, and I seem to have a stalled fermentation. Is there any evidence that pressurized fermentation inhibits yeast performance? Thanks in advance for your advice..

Minbari · Friday at 6:58 PM

Pressure fermentation absolutely slows fermentation. People usually ferment at higher than normal temps to counter it.

As far as a stuck fermentation. I dont know that the rules change. What temp did you mash at? Yeast health? Yeast strain?

Red Lion Brewing Company · Friday at 7:18 PM

Minbari said:
Pressure fermentation absolutely slows fermentation. People usually ferment at higher than normal temps to counter it.

As far as a stuck fermentation. I dont know that the rules change. What temp did you mash at? Yeast health? Yeast strain?

The usual... Mash target 150F, yeast was fresh and healthy, 2 WLP005, 1 WLP007 with 1L starter... Fermentation started strong and fast.. Glycol regulated temp at 68F... The only variable is playing around with the spunding valve vs. blowoff tube... I tried agitating the tank today, and will give it a few more days. I was curious whether anyone else had any experience with this issue... Thanks for your input... Cheers!!

Minbari · Friday at 7:28 PM

Red Lion Brewing Company said:
The usual... Mash target 150F, yeast was fresh and healthy, 2 WLP005, 1 WLP007 with 1L starter... Fermentation started strong and fast.. Glycol regulated temp at 68F... The only variable is playing around with the spunding valve vs. blowoff tube... I tried agitating the tank today, and will give it a few more days. I was curious whether anyone else had any experience with this issue... Thanks for your input... Cheers!!

Looks normal. Maybe raise it up to 73F to get it back going. 68F is the temp I would fermentc at with no pressure

Also, what psi are fermenting at?

Red Lion Brewing Company · Friday at 10:11 PM

5-10 psi..

Josh Hughes · Saturday at 12:10 AM

I regularly ferment this way. I have had fermentation stop/slow a few point away. Key is to warm it as it slows. So if you fermented at 68, raising it to low 70s when it slows can help. Sometimes the yeast are just done though.

Brew Cat · 2024-12-03T13:45:08+0000

When doing lagers which is all I do under pressure is after a week I will release most of the pressure and raise it to D rest temp . Drop the krausen then lower the temperature to finish. Never had it stuck but slower fermentation for sure. If you want to finish with a carbonated beer I usually have to build the pressure back up with tank CO2 and let it finish.