Fermenting under pressure

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

oldpathwhiteclouds

Active Member
Joined
Jan 19, 2015
Messages
66
Reaction score
17
Location
NULL
I’ve got my Sierra Nevada clone in my new fermzilla all rounder today. Long day.

It doesn’t fit in my beer fridge annoyingly so will ferment in my kitchen again.
At the moment I have an airlock in. I do want to try fermenting under pressure.

When should I switch out the airlock for the plastic pressure cap and spunging valve do you think? Immediately? After 48 hrs? Have read different things.
 
I’m no expert , but intend to christen my all rounder next weekend. My plan is to set my spunding valve on a known source to 5 psi and use that from the off leaving air lock redundant. Be interested to know how your brew goes . Cheers
 
Can’t help with your brew.But for my ipa’s I normally set my spunding valve for 10psi.For my neipa I have 5psi until first dry hop then let it rise to 10psi before enclosed transfer.
 
I’ve got my Sierra Nevada clone in my new fermzilla all rounder today. Long day.

It doesn’t fit in my beer fridge annoyingly so will ferment in my kitchen again.
At the moment I have an airlock in. I do want to try fermenting under pressure.

When should I switch out the airlock for the plastic pressure cap and spunging valve do you think? Immediately? After 48 hrs? Have read different things.
Read how the craft brewers pressure ferment, hang about, they don't pressure ferment. So read how all the writers on all things home brewing do it, Gordon Strong, Chris Colby, Palmer, Zainasseff, Fix and Dave Miller. They don't do it either. So why do some people insist on "Fermenting under pressure" because some plonker in the USA took this article from Teri Fahrendorf a respected brewer in USA. https://terifahrendorf.com/Closed-Pressurized-Fermenatation.pdf and completely got it so wrong that all the other sheep followed what he did. (It is I think the still longest thread on Homebrew Talk) Teri says cap at 36 hours, but really it depends on how robust the fermentation is, could be 48 hrs even 72 hrs this is all temperature/yeast dependent.
'Assume nothing question everything' we all have a mind capable of critical thinking, we have to use it, trace the source of pressure fermenting and it leads back to Teri Fahrendorf read her article and take RGeats advice, why, because you are stressing out the yeast for no reason by applying pressure.
I once sent an email to John Palmer to ask his thoughts on pressure fermenting, he wrote back and asked 'why would anyone do that'
 
Last edited:
I’m also really enjoying a mixed case of beers from Pressure Drop brewery in Tottenham Hale after a recommendation and figured they brewed under pressure but I could be wrong.
 
What are the potential benefits from Fermenting under pressure? If it’s because of that age old panic about wild yeast or whatever getting into the brew, then I am out now. We all know that’s a ghost story that old hat brewers tell to there apprentice to scare them into cleaning properly.
 
I ferment in a corny and finish fermentation under pressure by capping after 50-75% attenuation and any dry hopping. It saves having to pressure carbonate or prime then wait. It also enables closed transfer from the fermenter. It is fairly common practice in commercial breweries in UK and is
similar to what happens with cask-conditioned beer which is transferred to cask with on or two gravity points of unfermented sugars left in it and finishes fermentation in cask.
 
People ferment under pressure to suppress ester and fusel alcohol production, and ability to ferment at higher temps and so quicker (primarily for lagers). However I've found the biggest benefit is to allow oxygen free transfer at the end of fermentation, and allowing carbonation using the CO2 from fermentation, saving your CO2 and it's quicker.
 
So why do some people insist on "Fermenting under pressure" because some plonker in the USA took this article from Teri Fahrendorf a respected brewer in USA. https://terifahrendorf.com/Closed-Pressurized-Fermenatation.pdf and completely got it so wrong that all the other sheep followed what he did. (It is I think the still longest thread on Homebrew Talk) Teri says cap at 36 hours, but really it depends on how robust the fermentation is, could be 48 hrs even 72 hrs this is all temperature/yeast dependent.
Just to mention that Teri is a woman and a bit of a hero of mine Teri Fahrendorf - Wikipedia . I'm currently brewing her recipe for 'Bombay Bomber' that describes fermentation under pressure from day 4:
“Ferment at 67° F (19° C) for 18 days. On the third day, dry hop with Chinook at bunging. Beginning on day 4, make sure to keep top pressure on the beer to naturally carbonate. Pull the yeast on day 10. Chill to 32° F (0° C) for the final three days (days 19–21), and filter for a bright, crisp taste.”​

I'm really really early in experimenting with pressure brewing, and so far it's not worked out as well as hoped, I'm hoping this will be better. The main reason for pressure fermenting for me is to do closed oxygen free transfers which would be difficult to do otherwise, I also like the idea of natural carbonation through the fermentation.

Anna
 
That's the whole purpose, let there be natural fermentation until almost complete, cap it and let natural carbonation take it's course. Letting the DMS vacate the fermentation vessel before capping. I am positive if some bozo said we could do a 15 minute boil using a pressure vessel he would get a good following.
1613985743409.png
 
Commercial brewing aside, because they have there own reasons for doing what they do and let’s face it they are not all doing pressure fermentation. Some are still doing open fermentation and still producing incredible beer. I can’t see any good reason to do a pressurised fermentation.
Closed oxygen free transfer, also seems a little on the neurotic side at a home brew level. The amount of oxidisation during transfer is so negligible that the effect would probably go unnoticed to anyone but the most sophisticated of pallets. Besides with a proper keg set up you can carbonate in the keg and replace the air in the beer with Co2 very quickly before the beer is spoiled. People have been winning awards for there beer for years, without these techniques. I am all for progress but it seems to me that these techniques don’t really improve the beer at the end of the day.
Hay this is just my opinion. Maybe I should get with the zeitgeist and open up my mind to new experimentation.
 
Any brewery using cylindro-conical fermenters of a decent size is pressure fermenting.
I think you will find the tall cylindrical fermenters use paddles to alleviate hydro static pressure which is different to the back pressure caused by capping the spunding valve, which forces co2 back into the solution. Exo thermic currents keep the wort moving in smaller commercial vessels.
 
My pressure fermenting is currently lager only, and is in its infancy so I cant say for certain how it's going really. Still ironing out teething issues.

What I can say is that in that FV I currently have a carbed lager at FG that has had zero temperature adjustment, after 5 days.

It needs time to clear, and will closed transfer to keg, but ultimately, I could be bottling that in less than a week.

I think theres something in it. How much I have yet to determine and if it turns out not to be worth it, il just lob an airlock onto my fermentasaurus and crack on, but I do think can make lager production significantly more convenient using this. And lager is just my game.
 
Commercial brewing aside, because they have there own reasons for doing what they do and let’s face it they are not all doing pressure fermentation. Some are still doing open fermentation and still producing incredible beer. I can’t see any good reason to do a pressurised fermentation.
Closed oxygen free transfer, also seems a little on the neurotic side at a home brew level. The amount of oxidisation during transfer is so negligible that the effect would probably go unnoticed to anyone but the most sophisticated of pallets. Besides with a proper keg set up you can carbonate in the keg and replace the air in the beer with Co2 very quickly before the beer is spoiled. People have been winning awards for there beer for years, without these techniques. I am all for progress but it seems to me that these techniques don’t really improve the beer at the end of the day.
Hay this is just my opinion. Maybe I should get with the zeitgeist and open up my mind to new experimentation.
My beers used to lose aroma and flavour fast. I now ferment under pressure and close transfer. My beers no longer lose aroma and flavour. I can also ferment at a specific psi, depending on temperature, to get a more accurate carbonation level for the style of beer. There are a good few benefits to using them. I've only had mine about six months but I love it. Best piece of brewing kit I have bought.
 

Latest posts

Back
Top