Pressurised Fermentation practical use

[Paulus]

I agree in general and that is what I currently do. However, where I live the temperatures get up to 40C in July and stay above 30 until October. I have cooling but it is really pushed to keep a fermenting beer at 20C and later when bottled I have to keep it at 20C for 3 weeks until all the bottling sugar is consumed otherwise I get some very nasty tinged beer.
My idea is to use pressure fermenting so that I can take the "pressure" off my cooling equipment and maybe let fermentation go on at about 25C or higher (need to check that) and then leave the beer under pressure for a week before bottling meaning I don't need to do a 2nd fermentation.

I am, however, worried about pressure control as I have no experience in pressure fermenting and see nothing other than the emergency pressure relief valve to alleviate excess pressure which in my view is a bad thing. I am interested in whether the spunding valve will let pressure out if the fermenter pressure is higher than the set pressure and there is no gas attached.

The other option is that the fermentation does not produce that much pressure.

I am just asking for advice about pressure control is all.

 

[Sadfield]

Yes, you need a spunding valve to release excess pressure at a set point. Fermentation will create plenty of pressure.

There's no point waiting 2 days to put the pressure on if you are fermenting at high temperatures. Most esters are formed between 12 and 48 hrs. It's the CO2 in solution that you want in order to suppress esters and higher alcohols. It's the same thing we are doing by cooling fermentation.

"increasing concentrations of dissolved CO2 suppress yeast growth by unbalancing decarboxylation reactions (...) which are a fundamental step in either higher alcohol or acetyl-CoA synthesis" Pires 2015

↑ CO2 pressure ⇒ ↓ yeast growth ⇒ ↓ acetyl CoA synthesis ⇒ ↓ ester formation

What I would say, is avoid pressure during the lag phase where esters aren't produced. Waiting 6-12 hours should do.

A good way to do this is start with no excess pressure, but with a spunding valve closed. After the lag phase has finished yeast will start producing co2 and build pressure naturally in the vessel. Once the desired pressure is reached, open the spunding valve to release any pressure above this point. 0.5 bar (7.2 psi) would be a good place to start.

 

[Frisp]

I am, however, worried about pressure control as I have no experience in pressure fermenting and see nothing other than the emergency pressure relief valve to alleviate excess pressure which in my view is a bad thing.

watch this vid which explains how a spunding valve allows you to set and safely maintain the pressure within a pressure fermenter

 

[RoomWithABrew]

I would consider using yeasts that tolerate higher temperatures such as kveik strains and saison yeasts.
Some saison yeasts do not like pressure at all. I've fermented with kveik at over 30 C and lots of pressure, up to 30 psi and accidentally a hefeweizen over 35 psi.
It's a fallacy that the yeast stops working under pressure, it may not work as well or reach as low fg as you want but it still ferments.
If it couldn't how would bottle conditioning work? Champagne ferments to nearly six vols in some cases.
My Belgian golden strong I pressure transferred after spunding and cold crash at 2.3 vols and added more dextrose and yeast to get to 4 vols.
Somewhere I saw keg king ferment one of their vessels to failure and I think that was near 100 PSI.
What type of beer do you want to make? If you want a nice expressive cask ale at those temps and using pressure the spunding valve is not the solution.

 

[Sadfield]

If you want a nice expressive cask ale at those temps and using pressure the spunding valve is not the solution.

I'd say the same regarding cylindrical FV's and airlocks. The best traditional cask Bitter comes from the breweries that open ferment.

However, some breweries get close. And I feel it's possible with a careful use of pressure and not be extreme with it. Say, if the OP swapped 1 PSI of pressure for every couple °C. Temperature and pressure are both mechanisms for retaining CO2 in wort to suppress esters. If one was really clever they could calculate the DO at a range of temperatures and work it back to get exactly the same levels via top pressure at a given temperature.

 

[foxy]

I agree in general and that is what I currently do. However, where I live the temperatures get up to 40C in July and stay above 30 until October. I have cooling but it is really pushed to keep a fermenting beer at 20C and later when bottled I have to keep it at 20C for 3 weeks until all the bottling sugar is consumed otherwise I get some very nasty tinged beer.
My idea is to use pressure fermenting so that I can take the "pressure" off my cooling equipment and maybe let fermentation go on at about 25C or higher (need to check that) and then leave the beer under pressure for a week before bottling meaning I don't need to do a 2nd fermentation.

I am, however, worried about pressure control as I have no experience in pressure fermenting and see nothing other than the emergency pressure relief valve to alleviate excess pressure which in my view is a bad thing. I am interested in whether the spunding valve will let pressure out if the fermenter pressure is higher than the set pressure and there is no gas attached.

The other option is that the fermentation does not produce that much pressure.

I am just asking for advice about pressure control is all.

I live in a similar climate probably with higher temperatures than you. Depending on what you want to drink, the best thing you could do is build a cool room to ferment in and stash your grog. Otherwise, you will be forever at the mercy of the elements.

About 17C in the fermenting room.

 

[Davegase]

I have a question about pressure control on pressurised fermentation.
If I set the spunding valve to e.g. 10 psi after pitching, that pressure comes in from the CO2 cylinder. When fermentation gets going isn't the pressure in the fermenter going to rise?
What maintains the vessel pressure to keep it low?
Or is it just that the fermentation doesn't produce that much gas?

Makeup a jumper to connect your CO2 to your spunding valve to set the pressure. No need to add gas to the fermentation, allow fermentation to get going before adding the spunding valve. Once set your spunding valve won't allow pressure to go above the setting.

 

[Paulus]

Makeup a jumper to connect your CO2 to your spunding valve to set the pressure. No need to add gas to the fermentation, allow fermentation to get going before adding the spunding valve. Once set your spunding valve won't allow pressure to go above the setting.View attachment 96090

Hi Davegas, thanks for the info, where did you buy the valve/gauge in the photo. It looks better than those I have seen available.

 

[Davegase]

Hi Davegas, thanks for the info, where did you buy the valve/gauge in the photo. It looks better than those I have seen available.

I probably got it from AliExpress but they are available from UK suppliers including angel home brew.

https://www.angelhomebrew.co.uk/fer...ure-relief-with-integrated-gauge-0-15psi.html
Just realised your in Seville, there must be other suppliers in the EU.
All the bits in the photo are Kegland.

 

[Paulus]

I live in a similar climate probably with higher temperatures than you. Depending on what you want to drink, the best thing you could do is build a cool room to ferment in and stash your grog. Otherwise, you will be forever at the mercy of the elements.
View attachment 96089
About 17C in the fermenting room.

Your solution is pretty complete.
I'm just trying to keep costs down and installing a full Aircon then running it 24/7 at 17C is more than I do anywhere in the house at present.
I ferment/store in 2 small insulated chambers, which can be collapsed when not in use. keeping these at 20C in high summer uses a good 400W on an 80% duty cycle.
It is a good idea mind!

 

[Paulus]

I would like to know if anyone has experience with an Apollo 30L snub nose compared to a Fermzilla 30L all rounder?
A company in Germany recon they've had less than stellar feedback about the Apollo, but they are still selling the Fermzilla so not sure it's unbiased info to be honest.

 

[Davegase]

I would like to know if anyone has experience with an Apollo 30L snub nose compared to a Fermzilla 30L all rounder?
A company in Germany recon they've had less than stellar feedback about the Apollo, but they are still selling the Fermzilla so not sure it's unbiased info to be honest.

I've not had an all-rounder but I did have the Firmzilla 27 litre which was good, but I wasn't harvesting yeast and I was dry hopping through the lid, so my next purchase would have been an all-rounder, but instead I went with the Apollo snub nose.
I'm very happy with the snub nose my only criticism is the lid. I don't like screwing stainless steel ball locks onto a plastic thread.
Apparently a stainless steel lid is on the horizon which would resolve my only issue.

 

[Paulus]

I've not had an all-rounder but I did have the Firmzilla 27 litre which was good, but I wasn't harvesting yeast and I was dry hopping through the lid, so my next purchase would have been an all-rounder, but instead I went with the Apollo snub nose.
I'm very happy with the snub nose my only criticism is the lid. I don't like screwing stainless steel ball locks onto a plastic thread.
Apparently a stainless steel lid is on the horizon which would resolve my only issue.

Thanks for the reply. I like the Apollo thermometer tube into the center of the fermenter, I don't think there's any other real difference from the specs and what I can see so may well go for the Apollo.

 

[Davegase]

Thanks for the reply. I like the Apollo thermometer tube into the center of the fermenter, I don't think there's any other real difference from the specs and what I can see so may well go for the Apollo.

 

[Davegase]

The thermowell is great for monitoring temperature.
But by experimenting with keglands Rapt hydrometer I have found it is better to stick the inkbird or similar control sensor to the outside of the fermenter for better control of temperature.
If you use the control sensor in thermowell you will find there's a lag which will result in greater fluctuation in temperature.

 

[stuarts]

I'm very happy with the snub nose my only criticism is the lid. I don't like screwing stainless steel ball locks onto a plastic thread.

That was my only issue with the Apollo Snubnose . I ended up using Allrounders more because of it .

 

[Paulus]

That was my only issue with the Apollo Snubnose . I ended up using Allrounders more because of it .

So the all rounder has a metal thread or is it all plastic?

 

[Davegase]

So the all rounder has a metal thread or is it all plastic?

All rounder has plastic threads so ideally use the kegland plastic ball lock posts.

 

[stuarts]

So the all rounder has a metal thread or is it all plastic?

plastic on plastic for the Allrounder ,Metal on Plastic for the Apollo

 

[RoomWithABrew]

It will make a difference at what level you put the temp sensor in the thermowell. When ferment is active then it mixes really well. But once ferment slows there can be quite a gradient between the bottom of fermenter and near the top, I noted this because I use an Ispindel in the fermenter at the same time as the temp probe.