Fermenting under pressure

[SG114]

Hi all,

Watching this thread with interest!  Just invested in a pressure fermenter and spunding valve, likely to stick my first brew on next week.  Here's my thinking, please feel free to point out any potential pitfalls!

1. Do a simple recipe, probably the Unreal Ale.  Cheap, easy and no dry hopping.
2. Set up spunding valve.  From what I've read, you pressurise a vessel to, say  15 PSI, attach the spunding valve to the gas post fully open.  Wind it in until gas stops escaping at desired pressure, say 12 psi.  Don't turn it off completely though.
3. Ferment.  Two schools of thought here it seems.  Ferment at normal temp (18-20) or go higher if you don't want esters from the yeast.  Fermenting higher finishes it quicker.
4. Cold crash - optional.  If I do, probably release pressure to about 5 psi as lots of natural CO² will be absorbed into the colder beer (not sure about this!)
5. Decant from fermenter to keg using closed transfer.  Beer should be mostly carbonated due to natural CO² but might need a day or two on gas to finish it off.

I think I've made it sound way easy, there's got to be a catch right?

Cheers

Steve

 

[iBooz2]

@SG114 I do mine slightly differently.

1. Do my recipe as per whatever beer it's going to be.

2. Leave spunding valve pretty much open/set to low pressure until fermentation actually starts.  I have a bow off hose into a bottle of sanitiser which lets me know its up and away.

3. BD +1 Adjust spunding valve so it sits at about 5 psi during most of main ferment for first few days.  I think 15 psi is too high initially and yeast may stress out.

4. BD +4 or +5 as ferment slows and if not dry hopping close up spunding valve slightly to increase the pressure to build up to 12-15 psi and hold it there.  When you cold crash your beer the pressure will drop dramatically so always start the cold crash up around the 15 psi or higher as it will end up down about 3 psi anyway.   Don't burp it before the cold crash, that CO2 was made by your beer so keep it and use it to your advantage.

5. When ferment finished and FG reached, bump temp up by 2 C for two days then start cold crash, first down to 10 C then 5 C then 2 C.  From start of cold crash to kegging is exactly 1 week for me.

6. Always cold crash for the one week minimum as the beer becomes very clear without the need to fine with gelatin and so forth which leaves bugger all trub in the kegs when keg blows, maybe only a tablespoon of muck.  You will notice this very big difference when you come to clean them in readiness for your next batch of beer.  Cold crash is not optional for me at this stage.  I like what it brings to the finished beer.

7. Yes closed transfer is the way to go but may not be necessary if you drink your kegs within a couple of week or so.  Would think it would make a big difference though if it was a lager or a stout that would sit in your kegs for weeks, months or a year.

Cheers - AL

Edited June 4, 2020 by iBooz2
typos & spelling

[Marty_G]

19 hours ago, SG114 said:

Hi all,

Watching this thread with interest!  Just invested in a pressure fermenter and spunding valve, likely to stick my first brew on next week.  Here's my thinking, please feel free to point out any potential pitfalls!

1. Do a simple recipe, probably the Unreal Ale.  Cheap, easy and no dry hopping.
2. Set up spunding valve.  From what I've read, you pressurise a vessel to, say  15 PSI, attach the spunding valve to the gas post fully open.  Wind it in until gas stops escaping at desired pressure, say 12 psi.  Don't turn it off completely though.
3. Ferment.  Two schools of thought here it seems.  Ferment at normal temp (18-20) or go higher if you don't want esters from the yeast.  Fermenting higher finishes it quicker.
4. Cold crash - optional.  If I do, probably release pressure to about 5 psi as lots of natural CO² will be absorbed into the colder beer (not sure about this!)
5. Decant from fermenter to keg using closed transfer.  Beer should be mostly carbonated due to natural CO² but might need a day or two on gas to finish it off.

I think I've made it sound way easy, there's got to be a catch right?

Cheers

Steve

 

I ferment 90% of my brews under pressure there days.  There is absolutely no issue with setting the pressure to 15psi from the start and letting it build. I have used pressures from 5-15psi. done it with open spunding valve for a day or so then slowly added pressure. I have found that ales at 15psi work a treat.  I also use Kveik at pressure and can have the beer finished, cleaned up and in the keg in 72-96 hours.  I then  crash it.  I also use harvested yeast.  That way I am getting yeast that has been fermented under pressure and at higher temps.  Personally i think it is a great way to ferment ales.  Lagers I do a bit differently. I start them at 5 psi,  but at the top of the yeast temp range then add pressure to 10 on day 2 or 3 then increase the temp to about 18 and let it sit there till it is finished.  

[SG114]

17 hours ago, iBooz2 said:

@SG114 I do mine slightly differently.

1. Do my recipe as per whatever beer it's going to be.

2. Leave spunding valve pretty much open/set to low pressure until fermentation actually starts.  I have a bow off hose into a bottle of sanitiser which lets me know its up and away.

3. BD +1 Adjust spunding valve so it sits at about 5 psi during most of main ferment for first few days.  I think 15 psi is too high initially and yeast may stress out.

4. BD +4 or +5 as ferment slows and if not dry hopping close up spunding valve slightly to increase the pressure to build up to 12-15 psi and hold it there.  When you cold crash your beer the pressure will drop dramatically so always start the cold crash up around the 15 psi or higher as it will end up down about 3 psi anyway.   Don't burp it before the cold crash, that CO2 was made by your beer so keep it and use it to your advantage.

5. When ferment finished and FG reached, bump temp up by 2 C for two days then start cold crash, first down to 10 C then 5 C then 2 C.  From start of cold crash to kegging is exactly 1 week for me.

6. Always cold crash for the one week minimum as the beer becomes very clear without the need to fine with gelatin and so forth which leaves bugger all trub in the kegs when keg blows, maybe only a tablespoon of muck.  You will notice this very big difference when you come to clean them in readiness for your next batch of beer.  Cold crash is not optional for me at this stage.  I like what it brings to the finished beer.

7. Yes closed transfer is the way to go but may not be necessary if you drink your kegs within a couple of week or so.  Would think it would make a big difference though if it was a lager or a stout that would sit in your kegs for weeks, months or a year.

Cheers - AL

 

5 hours ago, MartyG1525230263 said:

I ferment 90% of my brews under pressure there days.  There is absolutely no issue with setting the pressure to 15psi from the start and letting it build. I have used pressures from 5-15psi. done it with open spunding valve for a day or so then slowly added pressure. I have found that ales at 15psi work a treat.  I also use Kveik at pressure and can have the beer finished, cleaned up and in the keg in 72-96 hours.  I then  crash it.  I also use harvested yeast.  That way I am getting yeast that has been fermented under pressure and at higher temps.  Personally i think it is a great way to ferment ales.  Lagers I do a bit differently. I start them at 5 psi,  but at the top of the yeast temp range then add pressure to 10 on day 2 or 3 then increase the temp to about 18 and let it sit there till it is finished.  

Hi guys,

Thanks for sharing your insights on this. It seems that, as with a lot of things in homebrewing, different people do things slightly differently.  

I do get the huge benefits of cold crashing and it's actually my preference - my old fermenting fridge takes forever to get down to the right temp though so sometimes impatience/low supply gets the better of me and I don't bother with it!

Haven't had my equipment delivered yet but definitely some points to ponder here, cheers!

Steve

[Cosmo2450]

4 hours ago, SG114 said:

 

Hi guys,

Thanks for sharing your insights on this. It seems that, as with a lot of things in homebrewing, different people do things slightly differently.  

I do get the huge benefits of cold crashing and it's actually my preference - my old fermenting fridge takes forever to get down to the right temp though so sometimes impatience/low supply gets the better of me and I don't bother with it!

Haven't had my equipment delivered yet but definitely some points to ponder here, cheers!

Steve

Don’t worry about your starting pressures. When I start a brew I’ll blow the oxygen out and then let the yeast build up the pressure to 15-20 psi. I don’t bother with using the collection bottle (because I can’t get it off) or even shutting the valve. Let the beer do it’s thang bleed pressure off and open the lid to dry hop. I blow the oxygen out (might not be necessary) and bung the lid back. 2 hours later it’s back up to pressure then I’ll drop the temp down to cold crash whilst it’s dry hopping. Four to five days max. Closed transfer. 
Result is flawless beers. 
 

I’ve had that drama of the beer line getting clogged up with hops, just blow the line back with co2. But I’ve only just started cold crashing and haven’t had that drama since. Also mid transfer I’ll fill up two stubbies for a cheeky beer. 
 

But you’ll be right. Pressure fermenting is easier and less stressful if you are kegging. 

[iBooz2]

@Cosmo2450 

Blowing the oxygen out (well blowing atmosphere out anyway) is probably not what you should be doing at very start of ferment.  You need that oxygen mix to assist at the very start, hence some people fizz their wort with O2 via sanitised bubble stones. 

I don’t bother purging the atmosphere out, just let the yeast do its thing and convert that little bit of O2 then build up the CO2 to desired pressure.  Most of the atmosphere will get pushed out the spunding valve as it ferments.  Basically the same as it would in a Coopers FV tub.

@MartyG1525230263I have not done a lager under pressure ferment as I want my lagers to be slow and low as the saying goes.  Cannot see the advantage of pressure cooking a lager brew or am I missing something.

Cheers - AL

[Cosmo2450]

31 minutes ago, iBooz2 said:

@Cosmo2450 

Blowing the oxygen out (well blowing atmosphere out anyway) is probably not what you should be doing at very start of ferment.  You need that oxygen mix to assist at the very start, hence some people fizz their wort with O2 via sanitised bubble stones. 

I don’t bother purging the atmosphere out, just let the yeast do its thing and convert that little bit of O2 then build up the CO2 to desired pressure.  Most of the atmosphere will get pushed out the spunding valve as it ferments.  Basically the same as it would in a Coopers FV tub.

@MartyG1525230263I have not done a lager under pressure ferment as I want my lagers to be slow and low as the saying goes.  Cannot see the advantage of pressure cooking a lager brew or am I missing something.

Cheers - AL

Oxygen in the wort from power drill assisted mixing. 

[Marty_G]

1 hour ago, iBooz2 said:

I have not done a lager under pressure ferment as I want my lagers to be slow and low as the saying goes.  Cannot see the advantage of pressure cooking a lager brew or am I missing something.

Well if super quick lagering and crisp flavour profile is what you want you are missing out. If you are doing a generic style lager such as an Asian rice lager it is perfect.  I don't use pressure for my Pilsners as I do them to style with a Czech yeast.  For most other lager there is no issue at all. Pressure fermenting of lagers is where the method is at its best. It suppresses ester and diacetyl production. 

[Pezzza]

On 3/13/2020 at 1:55 PM, PhilboBaggins said:

I'm confident she's nearly done so the D rest is underway.

How do you do a D Rest with a pressure fermenter - drop the pressure/increase the temperature - or?

[PhilboBaggins]

2 hours ago, Bearded Burbler said:

How do you do a D Rest with a pressure fermenter - drop the pressure/increase the temperature - or?

I don't drop the pressure at all. I just ramp it up a few degrees a few points from terminal gravity as I would any normal brew.

I'm very new to pressure fermenting though, so there may be more to it.

[ChristinaS1]

If you are fermenting at 20C or higher, I think you can just leave it (stable temp, stable pressure).  That is what I have been doing anyway. 

Just put on a lager. Hadn't done a pressure ferment in a while and actually forgot how to set the spunding valve. Accidentally attached it to the out post and got wort in the valve assembly.  Had to take it apart and clean it. After I reassembled it I had an gas leak, which took a while to fix. Good grief! 

With lagers, I apply pressure right away. With ale yeast, I wait for a couple of days (as long as ambient temp is <22C), so I still get some ester production. 

Truth be told, I have actually stopped fermenting ales under pressure because 1.) I like esters in my ales, 2.) I like 23L batches, and 3.) I like dry  hopping post fermentation.....Because I pressure ferment in a 19L serving keg, I have to reduce my batch size to 17L when I pressure ferment.

Cheers,

Christina.

Edited June 8, 2020 by ChristinaS1

[PaddyBrew2]

im gonna be doing my first pressure ferment tomorrow with the fermzilla all rounder. I have the blowtie and all the bits

I mucked up and got the wrong size gas line to attach to the regulator so i cant yet hit the vessel with pressure (i may go to the lhbs depending on the answer to the below)

do you need to hit the vessel with pressure after decanting the wort from the cube , or can you just leave it build up its own pressure and then adjust your spunding valve to the desired mark you want?

[ChristinaS1]

6 hours ago, PaddyBrew2 said:

....do you need to hit the vessel with pressure after decanting the wort from the cube , or can you just leave it build up its own pressure and then adjust your spunding valve to the desired mark you want?

It depends on whether you are making a lager or an ale. If you are making a lager, some say hit it with pressure (no more than 15PSI, I tend to use 10PSI) right off the bat. If you are making an ale, you can wait for 24-48 hours. What I do with ales is open the spunding valve up wide for 24 hours, then I take it off and put in 20PSI of gas in from my CO2 tank. Then I close the spunding valve completely and put it back on the keg, then slowly open it until it begins to hiss and the needle on the gauge comes down to my desired reading. 

If you let the pressure build up naturally you will end up overshooting your desired PSI and have to back it off. At least that is my understanding.

Cheers,

Christina.

Edited June 8, 2020 by ChristinaS1

[PaddyBrew2]

Cheers Christina 

Yeah doing an ale. I might just get the right sized line as I should test the vessel first beforehand as per the instructions

[BackyardBrewer]

Im glad I found this topic, I’m on my first pressure ferment right now and I’m making a “German” style ale using K-97 with German hops and malt. I’ve set my pressure to 15psi for the whole ferment after using the brewers friend keg carbonation calculator and seeing that 17c and 15psi should give me a beer with 2 volumes of finished C02 in solution. That way I will only have to top up the keg to get to the right level for serving. I am starting to think I’ve picked the wrong yeast for my first pressure ferment though as it produces a thick and persistent Krausen but it’s the beer I had ready to go so I’m going with the flow! I’m also using a new fermenter king junior from keg king, I bought two of them so I can ferment than crash and transfer to the second and ferment again in the first. I haven’t tried this yet and I was thinking I could possibly dry hop using hop tea, does anyone else do this in the serving vessel and does it work well?

Has anyone on this thread pressure fermented a dark beer yet? I’m thinking that I will probably continue to bottle with dark beers that I want to age a bit and my standard fermenter is probably best for that job?

[ChristinaS1]

7 hours ago, BackyardBrewer said:

Has anyone on this thread pressure fermented a dark beer yet? I’m thinking that I will probably continue to bottle with dark beers that I want to age a bit and my standard fermenter is probably best for that job?

I would agree with your plan to continue to use your standard fermenter for dark beers. Stouts make a lot of krausen.

[ChristinaS1]

On 6/4/2020 at 1:06 AM, SG114 said:

Set up spunding valve.  From what I've read, you pressurise a vessel to, say  15 PSI, attach the spunding valve to the gas post fully open.  Wind it in until gas stops escaping at desired pressure, say 12 psi.  Don't turn it off completely though.

I think you mean fully closed, and wind it out until the desired pressure is reached? If you start with it fully open, the gas you put in the keg will immediately escape.

Edited June 9, 2020 by ChristinaS1

[ChristinaS1]

On 6/8/2020 at 8:00 AM, ChristinaS1 said:

Just put on a lager. Hadn't done a pressure ferment in a while and actually forgot how to set the spunding valve. Accidentally attached it to the out post and got wort in the valve assembly.  Had to take it apart and clean it. After I reassembled it I had an gas leak, which took a while to fix. Good grief! 

Since getting wort up into the spunding valve, the pressure gauge doesn't seem to be working properly anymore. Might be sticky. May have to get a new gauge.

Edited June 9, 2020 by ChristinaS1

[Marty_G]

Just put down my 1st  pressure ferment of a true lager style using W 34/70.  OG 1050 pitched around 5pm last night at 20c and this morning is at 7psi which is about 1/2 way to full pressure. All other lagers I done under pressure have been pseudo lagers using Kveik at around 25c.   I have no doubt that it will be predicted ao I have great expectations for this brew.  There will be no  D-rest and the virtual elimination of Sulphur and phenol production this will make lager brewing so much easier. I am expecting this will see another shift in my brewing. The ability to get a lager from grain to keg in a week and the associated reduction in lagering time is a huge win.

 

[BackyardBrewer]

1 hour ago, MartyG1525230263 said:

There will be no  D-rest and the virtual elimination of Sulphur and phenol production this will make lager brewing so much easier. I am expecting this will see another shift in my brewing. The ability to get a lager from grain to keg in a week and the associated reduction in lagering time is a huge win.

I will be looking forward to the tasting notes for this. Im curious myself as i have one lager and one pilsner batch cold conditioning in my fridge at the moment and the fridge time they take up is really annoying so i would love to shorten that time. I also find 34/70 a bit fruity myself and im keen to pressure ferment it as well to see if i can get a cleaner beer with it, i used S189 for my laat two batches and that made a really nice neutral lager

[Marty_G]

36 minutes ago, BackyardBrewer said:

I will be looking forward to the tasting notes for this.

I should be able to have a taste in about 10 days.   I will cold crash and carbonate fully before I transfer to a serving keg so will have a taste at transfer.  It will then go into my keg bank to condition before its turn to go on tap. 

[SG114]

11 hours ago, ChristinaS1 said:

I think you mean fully closed, and wind it out until the desired pressure is reached? If you start with it fully open, the gas you put in the keg will immediately escape.

Thanks, this makes more sense I reckon!

[PaddyBrew2]

I have a question on the spunding valve. I'm pitched yeast last night. Closed the lid and didn't apply any CO2. This morning fermentation has started and pressure has been ramping up. I want to keep it at 10 psi. So I just checked an hour ago and it was around 12 so I opened the valve and backed it off until it stopped at 10. However just checked again and it's risen to 12. How do you know when to stop adjusting the valve to keep it at 10 cos I can still hear gas escape until I adjust it ever so slightly but then that appears to shut it off all together and the pressure just rebuilds 

[ChristinaS1]

I think it might be better to do it the other way around. See my earlier posts.

Cheers,

Christina.

Edited June 10, 2020 by ChristinaS1

[BackyardBrewer]

On 6/10/2020 at 2:42 PM, PaddyBrew2 said:

I have a question on the spunding valve. I'm pitched yeast last night. Closed the lid and didn't apply any CO2. This morning fermentation has started and pressure has been ramping up. I want to keep it at 10 psi. So I just checked an hour ago and it was around 12 so I opened the valve and backed it off until it stopped at 10. However just checked again and it's risen to 12. How do you know when to stop adjusting the valve to keep it at 10 cos I can still hear gas escape until I adjust it ever so slightly but then that appears to shut it off all together and the pressure just rebuilds 

Is it a keg-king spunding valve? I've got one of those and they are a bit touchy and I've found that if i bump mine sometimes even slight it will change by as much as 2 psi. Over time im getting used to it and can make adjustments that settle where i need them too, but im thinking of trying the bow-tie type down the track to see if they are more accurate