Fermenting Under Pressure

[wobbly]

What are the percieved advantages /benefits (if any) of fermenting the beer under pressure (15psi) as happens with the Kiwi Ssytem (forgotten the name) and the "Onederbrew" currently referenced under the topic "My Plastic Conical"?

I get it that the beer will be naturally carbonated at the finish of the fermentation period. And the pressure may/will assist in dumping the yeast cake out of the bottom of the cone.

Just wondering what other benefits there might be.

Cheers

Wobbly

 

[kevin_smevin]

What are the percieved advantages /benefits (if any) of fermenting the beer under pressure (15psi) as happens with the Kiwi Ssytem (forgotten the name) and the "Onederbrew" currently referenced under the topic "My Plastic Conical"?

I get it that the beer will be naturally carbonated at the finish of the fermentation period. And the pressure may/will assist in dumping the yeast cake out of the bottom of the cone.

Just wondering what other benefits there might be.

Cheers

Wobbly

Apart from the whole process being a little quicker, fermenting under pressure also reduces ester and fusel alcohol formation. I'm sure there are other effects but that's what i get off the top of my head.

 

[Bribie G]

When I was at Beervana in NZ a couple of years ago I was talking to a brewer who said that fermenting under pressure definitely gives a cleaner lager beer, as most Kiwi mainstreams are. In fact I was heretically impressed with the likes of Export Gold and Tui etc that they drink over there - pretty dismal megaswills but one thing you can say about them is that they are clean clean clean,none of the soapy mouse piss flavour you get in VB or Tooheys New. So what little malt flavour and hop flavour there was actually came through quite firmly.

 

[DJR]

When I was at Beervana in NZ a couple of years ago I was talking to a brewer who said that fermenting under pressure definitely gives a cleaner lager beer, as most Kiwi mainstreams are. In fact I was heretically impressed with the likes of Export Gold and Tui etc that they drink over there - pretty dismal megaswills but one thing you can say about them is that they are clean clean clean,none of the soapy mouse piss flavour you get in VB or Tooheys New. So what little malt flavour and hop flavour there was actually came through quite firmly.

The megas ferment under pressure here too, I wonder if the NZ brewers either lager for a bit longer, use less sugar, better yeast, or not such high gravity, or lower temperature

 

[Nick JD]

The megas ferment under pressure here too, I wonder if the NZ brewers either lager for a bit longer, use less sugar, better yeast, or not such high gravity, or lower temperature

Which brewery uses Morton Coutts's continuous technique?

 

[jyo]

I know 'Dent' on here has been experimenting with this method recently. I'll link him the thread. He seemed pretty happy with his initial results.

 

[dent]

Yeah, I've been giving the pressure ferment a go lately. The principle seems to be that CO2 pressure prevents the yeast from generating esters which would otherwise result from the warmer ferment.

I set it up in a 50L keg. I have a coupler connected with cornelius style adapters, with the spunding valve and pressure gauge attached to the gas post.

I brewed a 40L batch of pale lager with 2042 danish lager yeast - I used a whole cake of yeast from a previous non-pressure batch. I fermented at 14 degrees and 18 psi, however I was careful to start the ferment cold, at about 4 degrees on pitching. I do this so as to ensure a minimum of esters while there is not yet any top pressure. The ferment came up to pressure within a day or so, and then I set the temperature to 14 degrees - in this weather I need heating for lagers!

It is pretty amazing how much CO2 is generated when the ferment is going full blast, it is a like a gas leak going on in the fridge.

Anyhow the primary ferment was done in about six days - the beer was halfway carbonated at that pressure and temperature so it is nice for tasting the hydro samples. As advertised, the beer was not at all estery or fruity, there was no acetaldehyde, or diacetyl/VDKs. Good malt character. There was a fair bit of sulfur, which is to be expected with the closed lager ferment. This was pretty full on at day 7 but after another week it had mellowed out a great deal. The sulfur goes away on its own after a while, or you can wash it out with a bit more CO2 if you are in a hurry. It does give the beer a bit of a commercial character.

I actually dispensed 20 litres of this brew at a party that was on only two weeks after brew day, the keg got sucked down pretty quick, it stood well beside beers brewed traditionally.

I can post some pictures of the setup if anyone likes, it is pretty simple.

 

[Spoonta]

yes please on the pics

 

[Nick JD]

I fermented under pressure once with a HUGE Belgian that the yeast couldn't quite cope with. I kegged it way before FG to free up the fermenter and it finished ... eventually. I just burped the keg every day.

Was my best dark strong. Poor bugger too months to finish though.

 

[dent]

Ok, here are some pictures - pretty simple setup:

This spunding valve will just let the gas out constantly at a more or less regulated level. Others will reach a threshold and then release it. I hooked it up to my CO2 cylinder and tested it with the regulator to see what pressure and adjustment it started leaking at.

I like that with these kegs you can unscrew the spear and valve assembly, and you end up with a 60mm or so threaded entry at the top of the keg - I just fill the wort in through there rather than through the beer-in post, since it is quicker and I have to put the oxygenation stone in there anyhow.

The other part I like as fermenters, is that you can put a bit of water in them, then put the whole thing on the gas burner with the spear assembly loosened -- boil the hell out of it for excellent sanitation.

 

[redbeard]

Hi Dent,

how much wort do you ferment in keg ? is it in a fridge / freezer ? Do you use co2 to transfer it to a corny or another 50l ?

cheers

 

[dent]

I've been doing 40L batches in 50L kegs. I think if you tried a full batch for the keg volume it would work, but there may be trouble as yeast blowoff will get in the spunding valve and probably screw with the release setpoint.

I transfer the batch to 2 x cornies with CO2 as a closed system - out the fermenter beer-out, in the corny beer post. Best is to start with both ends at the same pressure, with the CO2 supply attached to the supplying keg, then you allow gas to slowly leak from the recieving keg, which will allow beer to flow in.

I do all the fermenting in the fridge, especially as I prefer to have a very cold start to the ferment during the growth phase - 4 degrees is a good starting point, then 6 until the pressure comes up (a day or so), then to 14. You could start at the higher temperature, but I think that would require you to pressurise the keg manually from the start - you'd have to keep the gas on too, as the gas will dissolve in the beer.

 

[booargy]

That is how I carb my beers by using it as secondary. May have to try it with the ferment.

PRV is SMC AP100-02 from RS components but I can't find it on their site.

 

[Nick_D]

Hey Dent, where did you get the adjustable relief valve on your setup? Do you remember a part name etc? I'm building a spunding valve but am struggling to find one of these little adjustable valves. Sorry to post in such an old topic..... If anyone else has any info, I'd really appreciate it, cheers.

Nick

 

[Danscraftbeer]

Dents post was nearly 4 years ago haha. I'm now pressure fermenting. I got the spunding valve set up ready to go from keg king.

I asked the question on Kegmenters and some info here: (more recent) http://aussiehomebrewer.com/topic/89407-kegmenter-are-they-good-to-use/

 

[wobbly]

OK at the risk of copping a bagging (again) I will offer details on the standard Williamswarn process for pressure fermenting

• Set the VPRV (spuding valve) to control at 1.5bar (21psi) for both Lagers and Ales - No issues with my brews (I haven't brewed any Belgians or Stouts) but the recommended procedures are the same
• Fermentation temperatures using dry yeast - Ale 23C for 4 days by which time terminal gravity is achieved PIlsner/Lagers 15C for 3 days followed by 18C for a further 3 days "D" rest - No issues with my beers
• At terminal gravity cold crash to 1C in one setting from fermentation temp and hold for 12/24 hours so as to drop the yeast out of suspension - No need to set temp to change in small daily increments
• I have brewed with US-05, Nottingham, W34/70, S23 and SO4 with no noticeable issues with the above temp/pressure/time regimes
• Following dropping the yeast then I clarify using a Colloidal Silica product at a rate of 2mls per liter over 24/36 hours and then consume

Wobbly

 

[siege]

OK at the risk of copping a bagging (again) I will offer details on the standard Williamswarn process for pressure fermenting

• Set the VPRV (spuding valve) to control at 1.5bar (21psi) for both Lagers and Ales - No issues with my brews (I haven't brewed any Belgians or Stouts) but the recommended procedures are the same
• Fermentation temperatures using dry yeast - Ale 23C for 4 days by which time terminal gravity is achieved PIlsner/Lagers 15C for 3 days followed by 18C for a further 3 days "D" rest - No issues with my beers
• At terminal gravity cold crash to 1C in one setting from fermentation temp and hold for 12/24 hours so as to drop the yeast out of suspension - No need to set temp to change in small daily increments
• I have brewed with US-05, Nottingham, W34/70, S23 and SO4 with no noticeable issues with the above temp/pressure/time regimes
• Following dropping the yeast then I clarify using a Colloidal Silica product at a rate of 2mls per liter over 24/36 hours and then consume

Wobbly

How does dry hopping fit into this system?

 

[dicko]

ADMIN:

Guys,

Please keep technical topic posts on topic.

 

[wobbly]

How does dry hopping fit into this system?

Dry hopping can be carried out at/close to the end of fermentation phase as/when the yeast starts to drop out of suspension by removing the sediment bottle, "disposing" of the settled yeast and then adding up to 3g/l of hops to the sediment bottle, adding about 500mils boiling water to the bottle and then stirring the hops to hydrate, then top up the bottle with beer foam and then reattaching the bottle to the WW and opening the butterfly valve.

This last step causes the hop liquid to shoot up into the fermentation chamber and over time it will resettle back into the sediment bottle

Leave the system like this for how ever many days and then remove the hop filled sediment bottle and cold crash and clarify as normal

Cheers

Wobbly

 

[Hoffdegg]

Hi Wobbly,

Im really interested in your method as it seems so quick, especially for lagers. I have just finished my lager in the traditional way (2 week at 9 degrees then 4 weeks at 4 degrees to lager) and it's way to long to wait!
I have just ordered myself a kegking pressure fermenter. Looking forward to testing it out...

When you do it your method under pressure, do you get a sulphar taste in the beer?
Do you still have to condition/lager the beer as you normally would have to with a lager?
So it is pretty much ready to drink after 7 days? And it matches up with a lager that has been fermented over 6-8 weeks?
The high pressure doesn't do anything to the yeast and produces a nice clean tasting lager?
Can yoh pitch off the yeast cake after fermenting at thag pressure or does the pressure kill the yeast over time?
Any information you can be given will be very much appreciated...
Hoff

 

[wobbly]

Hi Wobbly,

Im really interested in your method as it seems so quick, especially for lagers. I have just finished my lager in the traditional way (2 week at 9 degrees then 4 weeks at 4 degrees to lager) and it's way to long to wait!
I have just ordered myself a kegking pressure fermenter. Looking forward to testing it out...

When you do it your method under pressure, do you get a sulphar taste in the beer? Not that I or those that drink my beer can tatse
Do you still have to condition/lager the beer as you normally would have to with a lager? I don't normally brew lagers but the two that I have I have started drinking after about 9-10 days and they have lasted in the machine for about a few weeks and I haven't noticed any age related conditioning effects over time.
So it is pretty much ready to drink after 7 days? And it matches up with a lager that has been fermented over 6-8 weeks? In the Machine/Fermenter I have the standard cycle using dry yeast is 3 days at 15C followed by a further 3 days at 18C then cold crash to 1C for 12 hours to drop yeast out followed by two days of clarification phase using Silica Dioxide. All of this is carried out with the pressure relief valve set at 1.5bar
The high pressure doesn't do anything to the yeast and produces a nice clean tasting lager? I ferment at 1.5bar (21psi) and that has no detrimental effect on the yeast. Think about a large brewer where the tanks are 10 meters high and the pressure at the bottom of the tank is about 1.5bar. My understanding is that at pressure above 3 bar you will start to impact on yeast health
Can yoh pitch off the yeast cake after fermenting at thag pressure or does the pressure kill the yeast over time? Can't comment as I have never tried this with either lager or Ale yeast but I don't see why you couldn't harvest yeast for reuse after washing etc
Any information you can be given will be very much appreciated... You might want to down load the user manual from this site as that may be a good starting point for you http://www.williamswarn.com/Our-User-Manuals#.Vxgssf2Q-M8
Hoff

I have not seen the Keg King Pressure Fermenters so I'm not in a position to comment. The machine I use has been designed to do a number of sequences I mentioned in post #16 so I don't have to worry about things like temperature and pressure control, yeast harvesting, cold crashing, clarification and serving but hey that comes at a price (which I was and still are) happy to pay. It's not necessary to leave the finished beer in the machine until it is all consumed it is easy enough to transfer the carbonated beer to bottles or a keg if that suits you

As stated above down load this manual and have a read as it may answer a few of your questions http://www.williamswarn.com/Our-User-Manuals#.Vxgssf2Q-M8 There is also a hundred pages plus on the subject on Homebrewtalk that can be viewed at this thread. http://www.homebrewtalk.com/showthread.php?t=44344

Happy for you to PM me if you think I can be of further assistance

Cheers

Wobbly

edit for spelling

 

[Hoffdegg]

OK at the risk of copping a bagging (again) I will offer details on the standard Williamswarn process for pressure fermenting

• Set the VPRV (spuding valve) to control at 1.5bar (21psi) for both Lagers and Ales - No issues with my brews (I haven't brewed any Belgians or Stouts) but the recommended procedures are the same
• Fermentation temperatures using dry yeast - Ale 23C for 4 days by which time terminal gravity is achieved PIlsner/Lagers 15C for 3 days followed by 18C for a further 3 days "D" rest - No issues with my beers
• At terminal gravity cold crash to 1C in one setting from fermentation temp and hold for 12/24 hours so as to drop the yeast out of suspension - No need to set temp to change in small daily increments
• I have brewed with US-05, Nottingham, W34/70, S23 and SO4 with no noticeable issues with the above temp/pressure/time regimes
• Following dropping the yeast then I clarify using a Colloidal Silica product at a rate of 2mls per liter over 24/36 hours and then consume

Wobbly

 

[Hoffdegg]

Hi Wobbly,

Im really interested in your method as it seems so quick, especially for lagers. I have just finished my lager in the traditional way (2 week at 9 degrees then 4 weeks at 4 degrees to lager) and it's way to long to wait!
I have just ordered myself a kegking pressure fermenter. Looking forward to testing it out...

When you do it your method under pressure, do you get a sulphar taste in the beer?
Do you still have to condition/lager the beer as you normally would have to with a lager?
So it is pretty much ready to drink after 7 days? And it matches up with a lager that has been fermented over 6-8 weeks?
The high pressure doesn't do anything to the yeast and produces a nice clean tasting lager?
Can yoh pitch off the yeast cake after fermenting at thag pressure or does the pressure kill the yeast over time?
Any information you can be given will be very much appreciated...
Hoff

 

[Hoffdegg]

Sorry wasn't meant to post that twice...!

 

[Hoffdegg]

Thank you very much for all this information. Can't wait to give it all a go, guess all you can do is experiement/trial and error.

Thanks again
Hoff

 

[wobbly]

The 7 day cycle for Ales and 9 days for lagers is predicated on the basis that you can or are able to progress seamlessly from one step to the next using the machine/fermenter I have.

Being able to drop/dump the yeast at the end of fermentation is basically the same as could be achieved with a conical that has a bottom dump vale fitted - On my machine it requires no intervention, just happens and you can see where it is at.

The clarification phase is also easier as the system is built to be able to "Inject" it into the beer without having to release the Co2 pressure and open the device and thereby letting in Oxygen which isn't really desirable. Undoubtedly you could rig something to carry this phase out using a/the racking port somehow and "Inject" the clarification liquid in with Co2 pressure

I use Colloidal Silica Dioxide as my clarification liquid in preference to Gelatin as a personal preference for Mineral additions rather than Animal based

As for aging Lagers/Pilsners I don't see the need as the two I have brewed have turned out fine after 9 to 10 days "grain to brain". People talk about the need to allow the beer to "clean itself up" and I'm not sure just what they mean by this. If it's allowing time for the yeast to come out of suspension and take with it some of the sulfur taste then the clarification phase on my machine does this in a mater of a couple of days.

There is another topic on here somewhere that talks about using modified kegs to ferment under pressure and in that topic they mention that the lagers fermented under pressure are very clean to the taste and don't require the so called mandatory weeks of conditioning etc but I'm not sure if they also use some form of clarification liquid. I'm not knocking those that see it as being necessary brewing under atmospheric conditions it's just something I and others have found to not be required when pressure fermenting.

Cheers

Wobbly

 

[neal32]

What's the highest pressure anyone has gone up to during the active ferment?

I just got back from a work trip, I had a munich dunkel fermenting at 10 degrees at 15 psi for 10 days before I left and thought it was close to done so I capped the fermenter. It was a pitch onto a previous yeast cake of 2308 and only my second lager under pressure. I got back today and tried to put on the spunding valve and the pressure guage flatlined. I released what seemed like heaps of pressure to get it back down to 15 psi. So how high have the pressure fermenters among us gone?

I wiill update after a sample.

 

[malt junkie]

What's the highest pressure anyone has gone up to during the active ferment?

I just got back from a work trip, I had a munich dunkel fermenting at 10 degrees at 15 psi for 10 days before I left and thought it was close to done so I capped the fermenter. It was a pitch onto a previous yeast cake of 2308 and only my second lager under pressure. I got back today and tried to put on the spunding valve and the pressure guage flatlined. I released what seemed like heaps of pressure to get it back down to 15 psi. So how high have the pressure fermenters among us gone?

I wiill update after a sample.

This was discussed in another thread, you should be fine, maybe a lil over carbed perhaps?!

 

[neal32]

The sample tasted great and it was at 1.011. I'm slowing bleeding pressure until I get to 15 psi and then will recap, do a d-rest(unnecessary based on the sample but good practice) then down to 4 degrees for a couple of weeks until a keg frees up

 

[rude]

What type of spunding valve have you got on youre set up Neal