r/Homebrewing • u/brulosopher • Jun 22 '26
Under Pressure: Analyzing The Results From Past exBEERiments On Pressurized Fermentation
https://brulosophy.com/2026/06/22/under-pressure-analyzing-the-results-from-past-exbeeriments-on-pressurized-fermentation/10
u/jaytomten Jun 22 '26
Pressure fermenting still allows me to pre purge kegs with CO2 and perform pressurized closed transfers. So still a very valuable process for me to keep for my home brewery.
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u/Positronic_Matrix Jun 22 '26
Indeed. Pressurized fermentation has several advantages as follows:
- Warmer fermentation temperatures
- Closed transfers for oxygen sensitive beers
- Elimination of suck back when cold crashing
- Natural carbonation for immediate drinking
- Elimination of CO₂ loss to tank purging
It also solved my problem of conical getting clogged when brewing highly flocculant beers with a lot of protein. The floating dip tubes made all that pain go away. I also acquired a few Sanke kegs over the years and never used them because they were inconvenient. Now, they are my official fermenting kegs.
I think the juice is worth the squeeze if one looks beyond the meta-analysis published.
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u/BoyMeetsWort Brewgrass Homebrew Jun 23 '26
i agree that the purging of oxygen is the main advantage. I've had some great spunded beers, but it is tough to say that they are meaningfully cleaner than standard fermented ones.
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u/boarshead72 Yeast Whisperer Jun 22 '26
I loved that one with 808. It cracked me up when the lab results came in for the two beers and White Labs “designed for pressure” yeast blend was already totally fine at that temperature without any added pressure.
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u/bskzoo BJCP Jun 22 '26
Homebrew Happy Hour just had a good episode on pressure fermenting too. I don’t personally do it, but can’t argue with some of the competition results from last years Homebrewer of the year winner.
It was fun listening to his theories and methods.
Wayne Doucette I believe.
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u/fuzzdood Jun 22 '26
I add a spunding valve at the end of fermentation to get pressure to around 8 ps. I then remove it when cold crashing and the pressure prevents my plastic fermzilla fermenter from buckling inwards. Then closed transfer to keg, so no chance for oxygen to get in at any step.
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u/ThatTysonKid Jun 22 '26
This was an interesting read. Personally, I feel like most of the experiments were testing the wrong thing. Only Alex Shanks-Abel tested high pressure/high temp vs no pressure/low temp (modern vs traditional if you will). I'd like to see more data on this, as their findings were that it was indistinguishable under pressure or no.
As a side note, I prefer pressure fermentation because its more convenient and eliminates the risk of oxidisation, especially with hoppy beers. I use the waste CO2 to flush and pressurise my kegs too, so my whole brew is basically set and forget.
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u/deckerhand0 Jun 23 '26
I was thinking about getting into pressure fermentation, but a pro where I said you’re not gonna get the crispness or the results you think you’re gonna get. That’s sassy advice he gave me I personally haven’t done it yet but it’s always an idea that I’m toying with doing.
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u/BartholomewSchneider Jun 23 '26
The squeeze for me is ending up with perfectly carbonated beer, and that is worth it. I let the fermentation kick off at ambient pressure, then connect the spunding valve set to 25-30psi (depending on the temperature of my basement).
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u/ThatLemur Jun 22 '26
I understand stats but I feel like the structure of the experiment was never explained. Was one beer fermented under pressure and finished much quicker while the other was fermented traditionally, and then asked people to see if there was a difference in flavor? And since they couldn’t tell, the author is pro-pressurization..?
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u/the_snook Jun 22 '26
All the experiments reviewed in the linked article used the same temperature for both samples, with one pressurized and one not. None showed significant differences, so the reviewer's conclusion is somewhat anti-pressure.
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u/Ragadorus Pro Jun 22 '26
...you mean, besides the one where it was pressure fermented warm vs non-pressure fermented cold?
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u/the_snook Jun 22 '26
Right. One out of the nine. I missed that one.
That and the Helles fermented at 27°C are the only ones I find interesting really. Pale Ale at 20°C? What were they honestly expecting to find? I guess it can show that pressure fermenting isn't actively bad for the beer.
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u/Gileaders Jun 22 '26
As usual you idiots can’t find a difference in anything. I feel so sad for any newbie brewer that listens to your pseudo science bullshit.
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u/Positronic_Matrix Jun 22 '26 edited Jun 22 '26
False. They are correctly applying the scientific method. The results show that brewing is not as sensitive to many of the variables that bro-science had previously assumed. As such, it’s very useful to new brewers as it can help them focus on the things that do matter.
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u/Gileaders Jun 23 '26
The problem being at brulosophy nothing matters so you'll be improving nothing.
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u/chino_brews Jun 23 '26
You could be kinder, and also mind the #1 rule of this subreddit, Wheaton's Law.
Your comments are spoken like someone who is a true believer in how they do it, so are not open to other ideas. But maybe I am projecting something onto you that is not correct?
I'm not putting you in these camps, but we had people very angry and nasty about batch sparging back in the day because they were invested in fly sparging. Then the same thing happened with BIAB.
No one wants to believe what they are doing has no meaning.
But another way to look at the Brulosophy experiments is that humans are really bad at identifying, in a fair challenge, beers that are separated by one, little process or ingredient difference.
In some cases, the single variable is a whole technique and can be readily isolated, so by the volume of experiments and weight of anecdotal experiences, we can say it doesn't matter. Case in point, both sending the trub to the fermentor and "warm-ish" lager fermentation with certain strains have many experiments plus tens of thousands of batches behind them. Thus, I feel comfortable definitively saying that it's OK to run the trub to the fermentor and you can get indistinguishable lagers at both 50°F and 60-65°F with W-24/70, S-23, and S-189. Those deserve to be called good practices.
Yet, for many variables, it's also fair to say that one unknown variable alone cannot the identified by humans in the taste of beer, but when you start to cumulate some of the other "insignificant" factors in Brulosophy experiments, you will get identifiably bad beer.
Instead of railing against Brulosophy, my advice is to just evaluate whether it makes sense to you, with you equipment and techniques. If you see any flaws in their methodology, call them out on it.
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u/Gileaders Jun 23 '26
I have a better rule. Don’t lie to people so you can exist to sell them stuff. Plenty of peer reviewed scientific brewing knowledge out there. Maybe try spreading some of that instead.
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u/chino_brews Jul 15 '26
Do you have any peer-reviewed journal articles you want to make a post about?
I am not aware of any peer-reviewed journals with brewing info that are open access, other than the J. Inst. Brewing & Distilling, which is kind of a problem when starting discussions with the normal public. (JIDB apparently ceased publication in 2022.) The other issue is that from what I've seen, little peer reviewed research seems relevant to homebrewers and their scale, equipment, and methods. For example, none of the articles in the last issue of JIBD are really useful for homebrewers:
- The impact of caramel and roasted wheat malts on aroma compounds in top-fermented wheat beer
- Optimization of alkaline extraction of protein from brewer’s spent grain
- The effect of barley infected with xylanase-producing filamentous fungi on premature yeast flocculation
- Simulation of the behaviour of volatile compounds during batch multi-stage distillation of whisky
But maybe I'm missing some resources out there that you are aware of?
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u/Gileaders Jul 15 '26
Here are enough to keep you busy reading for a good long time. https://www.themodernbrewhouse.com/list-of-brewing-references/
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u/brulosopher Jun 22 '26
Over the last decade, we've performed many xBmts looking at the impact pressurized fermentation has on various styles of beer, mostly lagers, and the results have been quite interesting. This week, Marshall goes over all of those past xBmts in hopes of painting a more cohesive picture of this fascinating variable. Check it out!