# Fermenting Under Pressure at "regular" temps



## Vazerhino (8/6/18)

I have been using the pressure kit with fermentasaurus at 18 or 19 degrees. Happy with my results. Just wondering - is there any advantage apart from decreasing oxygen exposure? ie. my understanding is the advantage of fermenting under pressure is to decrease phenols and blah blah blah alcohols at higher temps. Seeing as i ferment at 18 or 19 degrees, am i simply slowing down my fermentation as it is under pressure? I still leave it ten to fourteen days - usually based on my need for another keg in the kegerator.


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## Uyllii (8/6/18)

Vazerhino said:


> I have been using the pressure kit with fermentasaurus at 18 or 19 degrees. Happy with my results. Just wondering - is there any advantage apart from decreasing oxygen exposure? ie. my understanding is the advantage of fermenting under pressure is to decrease phenols and blah blah blah alcohols at higher temps. Seeing as i ferment at 18 or 19 degrees, am i simply slowing down my fermentation as it is under pressure? I still leave it ten to fourteen days - usually based on my need for another keg in the kegerator.



+1 I want to know this too. I'm about to start pressure fermenting (getting 2x 29L kegmenters today) and was planning on doing my lagers at 9-10C @ 15PSI.


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## wide eyed and legless (8/6/18)

Teri Fahrendorf wrote an article for home brewers over 10 years ago for Zymurgy, the PDF I think it is called closed vessel fermentation, she relates to home brewers naturally carbonating the beer using the co2 produced during fermentation. Allow the initial fermentation gasses to vent then cap towards the end of fermentation to naturally carbonate the beer. Since that article was aired homebrew talk has ran with it for over 10 years and over 2000 posts so it has been misconstrued since her original article.
Here is a link to Pro Brewer which may help.
https://discussions.probrewer.com/s...the-purpose-of-quot-Capping-quot-fermentation


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## pirateagenda (8/6/18)

i find the carbonation is tighter than a force carbed beer if that makes sense - smaller more densely packed bubbles. 
i also find the beer stays fresh a lot longer due to less oxydisation


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## RoneMac (8/6/18)

Yeast can occasionally respond poorly to excessive head pressure and flocculate out earlier than usual.
I don't think this would be a problem on a home setup unless you were getting dangerously crazy with pressurising.


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## fdsaasdf (8/6/18)

RoneMac said:


> Yeast can occasionally respond poorly to excessive head pressure and flocculate out earlier than usual.
> I don't think this would be a problem on a home setup unless you were getting dangerously crazy with pressurising.


Or just had krausen block up your spunding valve


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## RoneMac (9/6/18)

fdsaasdf said:


> Or just had krausen block up your spunding valve


That too. You gotta get that head space right.

I might be wrong (I don't have a pressurised FV in use yet), but a blocked spunding valve wouldn't be too bad providing there's a PRV. Once the oxygen is purged from the vessel, shouldn't it just keep generating it's own carbon dioxide?

Valves can be a real pain to clean though.


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## fdsaasdf (9/6/18)

RoneMac said:


> That too. You gotta get that head space right.
> 
> I might be wrong (I don't have a pressurised FV in use yet), but a blocked spunding valve wouldn't be too bad providing there's a PRV. Once the oxygen is purged from the vessel, shouldn't it just keep generating it's own carbon dioxide?
> 
> Valves can be a real pain to clean though.



I think the concern is that the valve is blocked and then may either be stuck open and not pressurise, or becomes completely blocked and over-pressurises.


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## Yuz (10/6/18)

I've managed to get perfectly drinkable brews (to me) within five days + two days of "rest&settle" period once kegged. All fermented between between 80-120kPa and kegged / "conditioned" at a lesser pressure. The only time brew sees daylight and oxygen is when it's in the glass. I use a spare empty keg so there's no chance of liquid getting into the spunding valve. This spare keg is also my CO2 "accumulator" - free gas


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## Vazerhino (10/6/18)

Yuz- what temp are you fermenting at?


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## Yuz (10/6/18)

Vazerhino said:


> Yuz- what temp are you fermenting at?


Hey Vaz. Basically @ indoor brick garage ambient temp, with my old skiing jacket on the Fermentasaurus and a beanie over the collect bottle. It's not exposed to light and is well insulated. I also have a heating belt, it sits on the floor around the collect bottle with a couple of Alu angles - this setup seems to produce enough warmth to go up into the jacket and keep it warm at night.
I realise controlled fermentation temp is very important but this is a compromise of sorts. It works for me.


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