Fermenting under pressure

[RGeats]

wouldn't you disconnect to do the cold crash?

You can but there is no need.

Keep it connected and the pressure will drop a little as the CO2 is absorbed.

 

[krispn]

I’ve just taken delivery of a Fermzilla All-Rounder and spunding vale. I’m interested primarily in carbonating from the fermentation under pressure and closed transfers. It should be fun to re-brewing recipes I know and like and judging if there’s a measurable or perceptible difference to the quality by using a new technique... plus I just used a brew bucket for carrying water and cleaning when building a shed last week and it’s in no fit shape to be used for brewing again

The beauty is that if fermenting under pressure has no noticable impact on taste/flavour I can resort to my ‘old methods’ with the ability to capture some CO2 towards the end of the fermentation, perform a closed transfer and still enjoy the fruits of my labour.

At the end of the day I’ll have had the opportunity to try this ‘new to me’ process, I get to experiment with a hobby I enjoy and make up my own mind based on trial and error. If I can make it work the I’ll be happy and if It not a raging success there‘s bound to be some take aways I can incorporate..

 

[Braufather]

I’ve just taken delivery of a Fermzilla All-Rounder and spunding vale. I’m interested primarily in carbonating from the fermentation under pressure and closed transfers. It should be fun to re-brewing recipes I know and like and judging if there’s a measurable or perceptible difference to the quality by using a new technique... plus I just used a brew bucket for carrying water and cleaning when building a shed last week and it’s in no fit shape to be used for brewing again

The beauty is that if fermenting under pressure has no noticable impact on taste/flavour I can resort to my ‘old methods’ with the ability to capture some CO2 towards the end of the fermentation, perform a closed transfer and still enjoy the fruits of my labour.

At the end of the day I’ll have had the opportunity to try this ‘new to me’ process, I get to experiment with a hobby I enjoy and make up my own mind based on trial and error. If I can make it work the I’ll be happy and if It not a raging success there‘s bound to be some take aways I can incorporate..

Same position myself. I have the junior keg and spunding valve so will give it a go but it’s great to have anyway as you say for closed transfers and cold crashes etc. Might end up using mine as a conditioning dry hopping keg too.

First use I may not bother with a pressure ferment just to get used to using it though.

For non pressure ferments what do you set the spunding valve too?

Also if I’m not carbonating this time before transfer is it as simple as connecting liquid post to liquid post and opening the prv on the receiving keg?

 

[krispn]

Well once I get home after this nightshift I’m having a kip, then doing a NZ pale ale! I’m gonna ferment under pressure at the top end of the temp recommended for this strain of yeast (WHC Saunders dry yeast sachet) or maybe even just push it a little higher. It’ll be all hop stand and dry hop additions in similar quantities I’ve used in other brews so I have a decent idea of what to expect In terms of flavor/aroma. Once it’s done I’ll do a closed transfer to keg and maybe try a lager using the same method closely followed by a kettle soured Berliner Weisse!

To transfer you’d need to equalize the pressure in the All Rounder and the keg so the method I’m going to use is set both to the same psI with the spunding valve on the receiving keg then let off a little pressure until the liquid starts to flow. If you’re not carbonating in the AR then you’ll not have to worry about foaming in the keg but best to transfer after a cold crash while the beer is cold and make sure the receiving keg has been chilled too. If you did put the spunding valve on the AR (even towards the end of fermentation) you could capture some CO2 for the transfer).

I’m just gonna jump in and do a higher temp pressure ferment and use that captured gas to do the closed transfer. Why not just be bold and there’s enough time to watch a few tutorials between brew day and transfer even if it is a quicker turnaround!

 

[Braufather]

I’m just gonna jump in and do a higher temp pressure ferment and use that captured gas to do the closed transfer. Why not just be bold and there’s enough time to watch a few tutorials between brew day and transfer even if it is a quicker turnaround!

its an option, and ive a watched a few you tube vids, and as the junior keg doesnt have a lot of space, a pressurised fermentation will help keep the krausen down. it will be a cascade centennial 5/5% IPA, and no dry hop ( again to keep it simple) but a big hop stand. US05 yeast.

so maybe ferment at 5psi and raise it towards the end of fermentation to 20 psi, then after 10 days cold crash to 1c for 2 days. is there a recommended pressure during cold crash?

 

[krispn]

Sounds good! I’m not sure about cold crash pressure as I’ve not seen anything mentioned about changing or dropping pressure on the videos I’ve watched.

So I did my brew yesterday hit 1.048 (was aiming for around 1.044) in a 80/20 MO/wheat malt pale. Transferred into the All Rounder at 24c added my Saunders dry yeast and 1bar of pressure. This morning it had gone up to 2bar and fermentation had kicked off with a healthy krausen on top. Gonna leave it in and about the 2bar mark for 5 days before taking a gravity reading. I’ll be doing a dry hop of Simcoe and Riwaka (heavily favouring the Riwaka for this one at about an 80/20 split).

While the jury may still be out on the necessity of pressure fermentation it’s got me excited to try a ‘new process/technique’ and I’m looking forward to doing more brews with this method.

 

[muppix]

Let us know how you get on with that please!

I've got my third brew under pressure in the Fermzilla (Gen. II, 27 litre) and although it seems to be fermenting faster than I feel it would have without pressure, my main reason for doing it is so that I can keep oxygen at bay with closed transfers and CO2 flushed dry hopping.

During my own research I came across several sources which suggested a sweet spot of 10-12 PSI for fermentation after 1 or two days (for ale) so that some esters could be produced without pressure at the start. Anything more than 15 PSI is said to be in danger of stressing the yeast and 2 bar translates to around twice that amount. I'm still at the start of my journey as a brewer and there are many, many variables to play with, so I'm not yet ready to experiment with different pressures until I get a few brews under my belt, which is why I'm keen to hear about your experience.

 

[Braufather]

Sounds good. Will follow with interest.

 

[krispn]

Cheers for that @muppix I’ll drop mine down a bit and keep it lower for a day or two!

...and done! I’d actually read that too somewhere but got carried away with another chap who was fermenting at higher pressure in his videos. I’ll have plenty of time to experiment with pressure but other folks experience is always welcome.

 

[Braufather]

Let us know how you get on with that please!

I've got my third brew under pressure in the Fermzilla (Gen. II, 27 litre) and although it seems to be fermenting faster than I feel it would have without pressure, my main reason for doing it is so that I can keep oxygen at bay with closed transfers and CO2 flushed dry hopping.

During my own research I came across several sources which suggested a sweet spot of 10-12 PSI for fermentation after 1 or two days (for ale) so that some esters could be produced without pressure at the start. Anything more than 15 PSI is said to be in danger of stressing the yeast and 2 bar translates to around twice that amount. I'm still at the start of my journey as a brewer and there are many, many variables to play with, so I'm not yet ready to experiment with different pressures until I get a few brews under my belt, which is why I'm keen to hear about your experience.

So For the first couple of days do you set it to 1psi or something or use some type of blow off attached to the gas disconnect?

 

[krispn]

In my case I’m using a spunding valve but didn’t think to set it lower to release the excess over and above as I put the wort in at about 1bar but it’s naturally risen. Thinks it’s tweaked to release the excess now!

 

[krispn]

Double post!

 

[muppix]

So For the first couple of days do you set it to 1psi or something or use some type of blow off attached to the gas disconnect?

I've been using the black plastic coke cap and regular airlock that came with my Fermzilla for the first 24-48 hours, then I swap it out for a carbonation cap and Blow Tie spunding valve, letting pressure build naturally until I can set it at 10 PSI. By the 36 hour mark that takes around 30 minutes.

 

[Braufather]

I've been using the black plastic coke cap and regular airlock that came with my Fermzilla for the first 24-48 hours, then I swap it out for a carbonation cap and Blow Tie spunding valve, letting pressure build naturally until I can set it at 10 PSI. By the 36 hour mark that takes around 30 minutes.

Ive the junior king keg so just keg fittings. im thinking if i just connect the gas connect then CO2 can escape as usual during fermentation, i can then add the spunding valve after 3 days and set to 10 psi - sound about right?

 

[muppix]

Sounds about right provided the pressure is less on the outside of the gas disconnect than the inside, and as long as nothing can get into your FV that way. You could always put the spunding valve on now and set the back-pressure very very low, assuming you have a scale or a dial to work with?

 

[Jim Brewster]

Saw this in a magazine today, this is the opposite of what I thought which is that pressure reduced the stress on the yeast, which then stops them producing esters/phenols

 

[BlackRegent]

The magazine is correct. The received wisdom is that pressure stresses yeast and stops it behaving in the way it wants to, hence the reduction in esters

 

[Jim Brewster]

Ah I see, I had though it was the stress that produced the esters, I must have had it backwards.

 

[krispn]

It's my understanding that this is the reason it's good for high pressure/high temp 'fast' lagers rather than ales and such.

 

[Braufather]

Sounds about right provided the pressure is less on the outside of the gas disconnect than the inside, and as long as nothing can get into your FV that way. You could always put the spunding valve on now and set the back-pressure very very low, assuming you have a scale or a dial to work with?

Ok I guess the key time is the lag period before co2 is created. For that time it will be sitting in a brew fridge of ambient temp 19, which should be about the same as the wort. So to ensure presure is greater inside the keg is it better to have ambient temp greater or lower than wort?

I have a dial to set it but what is the benefit is setting it now? as it will be opened up again to receive the wort?