** Just a note prior to my post here.
This topic has frustrated me somewhat. However that is not directed at any one, or their brew methods. Rather, at how quickly information is often skewed and then falsely propagated.
Just wanted to make that clear before any takes the below personally
Hmmmm not really... the jury isn't still out on this. The media just kepts neglecting to include ALL relevant the pieces of information that the lawyers have presented, and keep drawing uneducated conclusions.
"Many labs conclude that pressure reduces the formation of esters and fusel alcohol,
Good podcast Chris White/Brad Smith/John Blichmann - "european brewers teach this (pressurised fermentation) as a technique ... produced a lager much faster and does work - Chris White" "
Where's the rest of this quote??
One can also quite easily say: "Beer...is always bad". When "..." has replaced "that is infected with Megasphaera Cerevesiae".
Context is everything!
As for "european brewers teach this......".
I live, work, study, eat, sleep, breathe brewing in Bavaria. This is where THE universities on brewing are. This is where they've been refining brewing for almost a thousand years.
Every day I go to uni with 50 other german brewers, from 50 other german/european breweries. 9 hours a day I get ear-bashed by lecturers who have written doctorates on these topics!! I can't have a conversation without a (non-brewer) friend asking me something about beer, or hearing from other brewers about beer and brewing.
Do you know how many of these people ferment under pressure in their breweries????
Have a guess..
One.
That I know of.....But, there may be one or two others who have done it under extreme circumstances.
And that one is not from a brewery known for high quality beer. They're very well known. Especially for their extremely low prices.
Do you know how they achieve these low prices? By cutting corners where other breweries don't. Do you know where the first place to cut corners is with lager beers?
Here's a hint. Lager means "to store". Which, equals time. And, as everyone knows, time equals money.
The reason they ferment unter pressure, is as a BAND-AID-FIX to the problems associated with fermenting so quickly (i.e. at such high temps!)
I know from a brewer from said brewery, that they pump out a "lager" beer in around 13 days. From mash through to bottling. At around 1/2 - 1/4 the time that most breweries take, that's extremely fast. That's also why they can sell cans at 30c instead of 90c like everyone else in Germany. That's also why it's most popular among the unfortunate people who reside in train stations and students who can't afford anything tastier.
Don't get me wrong, on a technological level, such breweries are cutting edge. They tend to have the best equipment, extremely skilled people and some of the best analyse-equipment for beer flavours/aromas that exist.
They know exactly what they're doing. And that's the point! They're not trying to make the best beer they can.
....they're trying to get as many hectolitres out each $ as they can.
Which isn't really the motivation behind homebrewing.
Sure "Many labs conclude that pressure reduces the formation of esters and fusel alcohol," ...absolutely! But that statement in itself is meaningless! "Reduces"...how much? Compared to what? What else is happening?
Yeah, it reduces said production.....also reduces the yeast's ability to breakdown such bi-products.
It also reduces the CO2-Wash, which is largely responsible for removing lots of "young" biproducts from the beer. It's also reduces the amount of yeast that stays in suspension, further reducing the effecience and extent of the conditioning phase.
One could also say "putting a plastic bag over your head reduces the amount of condensation on the car windscreen in winter"
Sure it does....but that's kinda missing the point
Similar to Mark's reference from Kunze, I have another complete textbook completely on fermentation (not sure if it's available in English, otherwise I'd highly recommend it). They have a subsection on pressurised fermentation of course. There was a lot of experimenting with it around the 60's. Of course, they list the pros and cons of the method. They also mention a bunch of interesting prerequisites in order for it to 1) work well and 2) be worth the while in any capacity at all.
And, unsurprisingly, the entire subtext of this technique, is with respect industry brewing, where every hour of fermentation/lagering equals $$$.
So, please, oh pleeeeeeease, stop deliberately supressing they yeast while asking it do a bunch of work for you!!!!
I'm at a loss trying to comprehend why this has become a thing in homebrewing, when there are SO many other things to optimise, and....the entire method is a Band-Aid to a problem that doesn't exist in homebrew.
If you really wanna optimise the fermentation, start looking in more detail into all the things that you feed the yeast. i.e. the make up of your wort. Which, is of course the outcome of your mash. Which of course, is dependent on your malt.
I'd highly recommend investing time into learning how to read a malt-analysis and the flow-on affects of that, than trying to recreate a method that's irrelevant.
But, if you REALLY really are hell bent on proving to yourself that it's possible to ferment under pressure. Go for it. But read up on it properly. On all the pros and cons. And take into account why some breweries use this method at all.
And stop being surprised at having so many fermentation problems
On that note, I'm gonna enjoy a delicious naturally brewed helles from a brewery that has been around since the 1300's and study for my exam on "Potential infections and microorganisms in the brewery", a significant part of which is the metabolism of yeast...including specifics on aerobic and aerobic energy generation and the role of NADH/H+
Cheers!
Oh, and keep on brewing
just be careful of how much misinformation is floating around out there in the homebrew-community :/
