Pressurized Fermentation- Fermentation Rate Slowing

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micraftbeer

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I'm doing my first fermentation under pressure. I'm using FermZilla All Rounder with its pressure kit, Blowtie spunding dialed in to 15 psi. I started fermentation with no pressure, and let the fermentation process build pressure up to the 15 psi, with some adjustments to blowtie until it was staying at 15 psi.

I'm fermenting a Rye Lager, using Wyeast 2308 Munich Lager yeast. I've used this yeast (not the exact batch) recently to make a Sam Adams-esque Lager. That one I fermented at 48F and it was slow and steady fermenter. This time, with the pressure, I am fermenting at basement room temperature, which happens to have the beer at 67F. It's started slow and steady as well. I had thought with the +20F temperature it would be going much quicker- but again this is my first pressurized ferment so I guess I didn't really have a basis for that.

Now I started adding some heat to get it up to 70 - 72F to speed things along, and I'm not really seeing it. Looking at my Tilt trend, it almost looks like it's going to plateau out at a high FG.

My question for pressure fermentation gurus out there, do you do anything special towards the end of your ferments to get them to finish off?

Recipe
68% Maris Otter
17% Rye Malt
6% Munich
5% Caramel 20L
4% Caramunich

Mash Schedule
100F for 15 min
122F for 20 min
152F for 60 min
168F for 10 min

Brew Stats
Mash Efficiency 82%
OG 1.057
Screenshot_20210506-131140.png
 

Gusso

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I'm new at pressurized fermentation for lagers. I've done 4 in the last couple of months with success. I have kicked up the psi to 25 from the start. I also have the temp in the low 70's. At that temp and pressure, one pack of 34/70 is plenty for the job. So far, so good.

Btw, my fermentations have started quickly and are done in 5-7 days.
 
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micraftbeer

micraftbeer

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I found it was still progressing, I just had to increase the temperature some. I'm hindsight I can't really see the spot where I was concerned it was plateauing...
Screenshot_20210509-112851.png


This is now 6 days after fermentation started. Bubbles starting to slow, I'm guessing it will continue to drop a few points over next day or two. This is the cleanest Tilt trace I think I've ever had. I guess the pressure keeps the krausen under control and therefore doesn't mess with the readings.
 
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DuncB

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The pressure does effect the tilt / spindel but even high pressures don't seem to stop the ferment. I've built the pressure up to 30 psi for a kveik lager ferment with the aim of it having the correct carb at the end of fermentation. Higher pressure seems to get cleaner with a warm ferment.
I use this Beer Carbonation Calculator
to guide my final ferment pressure.
 
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