Pilsner, fermentation under pressure, temp and pressure?

[Leonie Hill]

Hi to all of you out there,

It’s time to try to make a pilsner. I plan to ferment under pressure with an 30l All Rounder from Kegland.

My local brew shop has one type of lager/pilsner yeast and that is M76.

Mangrove Jacks’s recommend to ferment at a temp between 8-14 degrees C. (45-57 degrees F.).

My plan is to ferment at 10psi and 18 degrees C. (64 degrees F.) and for one week only before ragging the beer to a keg.

I would appreciate any guidance i can get. Will this yeast work for what i intend to do or am i better of looking for an alternative yeast?

best regards
Erik

 

[zacster]

You say yourself that fermentation is at 45-57F. That’s what makes lagers a lager. 64 is too warm. It’ll be beer but it won’t be a clean tasting lager.

 

[crazyjake19]

You say yourself that fermentation is at 45-57F. That’s what makes lagers a lager. 64 is too warm. It’ll be beer but it won’t be a clean tasting lager.

Not necessarily. Fermenting under pressure at room temperature will suppress ester production and can yield a very clean tasting lager. I use White Labs WLP925 yeast with this method, though many lager yeast strains can be used.

 

[Broothru]

You say yourself that fermentation is at 45-57F. That’s what makes lagers a lager. 64 is too warm. It’ll be beer but it won’t be a clean tasting lager.

Don't believe that's necessarily true when fermenting under pressure. Lager yeasts when fermented under pressure (5~10 psi) supposedly prevent off-flavors from developing, especially at higher temperatures. From what little I've read (and never tried) it can greatly reduce not only the time spent in fermentation but also in conditioning (lagering). Apparently it's a technique used by the macro brewers to speed up output at the brewery.

 

[zacster]

I'd forgotten that I'd replied to this. I guess I didn't know. If you ask me though, fermenting at the cooler temps is easier than establishing the pressure in the first place, but if you've already got the equipment have at it. Can this be done in a corny? And do you apply CO2 to get the pressure?

 

[Gruel]

So, what is a good pressure for lager (pilsner) fermenting? By itself the keg will easily go to 1.5 bar (hooked up to an empty second keg; both 5 gallon). So far I have twice bled it down to 0.5 bar. 1 bar = 14.5 psi or such.

 

[Abhishek Dewan]

So, what is a good pressure for lager (pilsner) fermenting? By itself the keg will easily go to 1.5 bar (hooked up to an empty second keg; both 5 gallon). So far I have twice bled it down to 0.5 bar. 1 bar = 14.5 psi or such.

I’m currently fermenting with fermolager w yeast (Pilsner yeast) at 20 psi. It’s been 8 days and still fermenting, OG was 1.044. I took samples, no off flavors and beer tastes good. I’ll put in fridge tonight I hope. I’m fermenting at rather extreme temperature of 33c. Going well, fermenting in fermzilla.

 

[SmallScaleOperator]

I get good clean tasting lager type beers fermenting at 15 psi, around 70 degrees Fahrenheit.

 

[Gruel]

Thank you both! Abhishek, that's quite the temperature! I guess I'll bleed down to 1 bar then. The keg is at 16C or 61F, with Saflager W-34/70 yeast (2nd generation; first time used in Feb.2020; specs are 12-15C for this yeast). One of the pressure adjustments pushed some foam/Krausen into the gas line. I was more careful with the last one.

 

[SmallScaleOperator]

Yes when you bleed off pressure you have to go slow. I use my spunding valve when I transfer too. I set my regulator to 17 psi or so and and the spunding valve stays at 15. It takes a bit of time, but I don’t get a keg full of foam like I did the first time I used the PRV to bleed off the pressure.

 

[Abhishek Dewan]

Thank you both! Abhishek, that's quite the temperature! I guess I'll bleed down to 1 bar then. The keg is at 16C or 61F, with Saflager W-34/70 yeast (2nd generation; first time used in Feb.2020; specs are 12-15C for this yeast). One of the pressure adjustments pushed some foam/Krausen into the gas line. I was more careful with the last one.

I was initially thinking pressure might push Krausen lower. I had beautiful Krausen and it lasted 4 days. The yeast I’m using is German and W34 is similar as I was told and found on the net as well. Both perform well under pressure. Other advantages of pressure fermentation are compact yeast cake, hops aroma is retained so I actually used an oz less of hops. I saved some wort and am fermenting at lower temperature and will see if there’s perceivable difference.

 

[The M]

Not necessarily. Fermenting under pressure at room temperature will suppress ester production and can yield a very clean tasting lager. I use White Labs WLP925 yeast with this method, though many lager yeast strains can be used.

I have also heard that fermenting under pressure at room temperature can yield clean tasting lager.

Question about WLP925. I have one old keg in storage and I'm planning to try fermenting lager under pressure at room temperature in that keg. Haven't tried keg fermenting before and WLP925 is also yeast that I haven't used before. Any advice what should be taken into consideration while using WLP925 & keg fermenting?

 

[BierHobo]

Hi to all of you out there,

It’s time to try to make a pilsner. I plan to ferment under pressure with an 30l All Rounder from Kegland.

My local brew shop has one type of lager/pilsner yeast and that is M76.

Mangrove Jacks’s recommend to ferment at a temp between 8-14 degrees C. (45-57 degrees F.).

My plan is to ferment at 10psi and 18 degrees C. (64 degrees F.) and for one week only before ragging the beer to a keg.

I would appreciate any guidance i can get. Will this yeast work for what i intend to do or am i better of looking for an alternative yeast?

best regards
Erik

It's been a while, but how did this turn out? I am currently running my first pressure ferment at both 10psi and 64° as well. Wonder how long it took to complete fermentation and how yours came out?

 

[Jim R]

I bet his beer turned out well. When I ferment under pressure, I usually use this calculator and ferment at the room temperature of my basement (usually 60-65 degrees). I set the pressure with my spunding valve to the pressure from this calculator based on my desired final carbonation level up to my top limit of 20 psi or so. There are definitely people though that are fermenting at pressures over 20 psi if their fermenter allows it and brewing lagers in amazingly short times.

https://drhansbrewery.com/beercarbonationcalculator/

 

[BierHobo]

Well, for me it's been 3 full days since I pitched yeast and at this point it appears the majority of fermentation is over. I wanted to take a sample, but for some reason my floating dip tube setup is not working as it should so I am getting nothing. I will have to open the corny to get a gravity reading, but I'm thinking to wait another couple of days. Trying to limit any air contact, ya know?

 

[McKnuckle]

What would be the point of taking a gravity reading after only 3 days of lager yeast fermentation? Fermentation under pressure takes more time, not less. If anything, the warmer temperature and the pressure cancel each other out in terms of time reduction.

Also, how would you know that the majority of fermentation is over if you can't see the beer or grab a sample?

 

[BierHobo]

I'm thinking quick fermentation based on various videos/articles/etc. where some people are fermenting lagers under pressure and are drinking it within 2 weeks of brewing. I am, in fact, trying to ascertain what the truth is regarding this.
As far as fermentation being over, well, that just the eye test. I have the gas out going to a bottle of water. There was vigorous bubbling going on and now nothing.

 

[Beermeister32]

On a commercial scale, what kind of pressure is placed on the fermenting yeast in those large tanks? Is this a similar procedure scaled down for home brewers?

 

[Vale71]

On a commercial scale, what kind of pressure is placed on the fermenting yeast in those large tanks? Is this a similar procedure scaled down for home brewers?

Starting with 0.5 bar at the beginning and ending with about 3 bar to get fully carbonated beer at 18-20°C. Yeast is also pitched colder and temperature rises throughout fermentation.

 

[Julian Høstan Urrea]

What would be the point of taking a gravity reading after only 3 days of lager yeast fermentation? Fermentation under pressure takes more time, not less. If anything, the warmer temperature and the pressure cancel each other out in terms of time reduction.

Also, how would you know that the majority of fermentation is over if you can't see the beer or grab a sample?

Where are you getting your information? The higher the temp, the faster the fermentation. The reason we don't ferment at high temps are the off tastes that the yeast give when you do. If you are fermenting a lager with lager yeast at let's say 30c and 22psi it will most defenitly be done in under 5 days. The cold crash and then drink. This is why kveik works as it does. You can ferment it high without pressure and it'll still turn out awesome in very little time.

I have been fermenting everything I make under pressure. I've mostly been using Voss ad Horningdal Kveik, but I've also used US-05, s04, and others. I even made several wine kits in under a week using high temps and high pressure. They all come out sooo clean. Only thing I would make in normal buckets now are Belgian beers, or something that needs the yeast flavor.

 

[McKnuckle]

The higher the temp, the faster the fermentation. The more pressure, the slower the fermentation. Mix the two together and it's essentially equivalent to a standard cool, un-pressurized fermentation. Simple point.

 

[Julian Høstan Urrea]

The higher the temp, the faster the fermentation. The more pressure, the slower the fermentation. Mix the two together and it's essentially equivalent to a standard cool, un-pressurized fermentation. Simple point.

Have you tried pressurised fermentation?

 

[BierHobo]

The higher the temp, the faster the fermentation. The more pressure, the slower the fermentation. Mix the two together and it's essentially equivalent to a standard cool, un-pressurized fermentation. Simple point.

What, exactly, has been the experience of people pressure fermenting here?
The most authoritative thing I've seen is the podcast with White and blichmann where they say they were serving pressure fermented bier in two weeks. This seem to point to a pretty short lager fermentation time.

 

[McKnuckle]

Have you tried pressurised fermentation?

Yes I have. I can tell there's a disconnect here, so we'll agree to disagree and I'll move along.

 

[SmallScaleOperator]

What, exactly, has been the experience of people pressure fermenting here?
The most authoritative thing I've seen is the podcast with White and blichmann where they say they were serving pressure fermented bier in two weeks. This seem to point to a pretty short lager fermentation time.

For a starting gravity of around 1.060 at 65 or 70 degrees and 15 psi, I would say from personal experience a week should be sufficient for fermentation.
I still do all my lagers at room temp under 15 PSI. I give them a week in primary, then a week in the keg on CO2 at serving pressure. They always come out nice and clean. I'm not saying they come out better than a traditional fermentation, just that I cant tell the difference, and it saves on my electric bill.

 

[DuncB]

I did an Asahi clone 15psi with opshaug kveik at 35degrees ( celsius ) for five days and then cold crashed, after a week it was clear no off flavours or esters and have been drinking it now for over a month. I also did a Cream stout clone with the same yeast and similar schedule and again tastes great. If the fermenter tolerates higher pressure then adjust spunding valve after 2 days to 25psi and let the yeast clean up and build this last bit of pressure before crashing. Both are better for a few weeks in the fridge than at first tasting.
Maybe I could have crashed sooner but I wasn't able to get access to the crashing freezer as it was blocked by another brew.
I have pressure fermented an NZ pilsner at lower temperatures using white labs High pressure lager yeast ( 20 C raising to 22 after 3 days) for a competition and that was 2 weeks mash to bottle and a week in bottle before judging ( not sure of cold chain after it left the house) . Came third so was pleased.
I would say that I found the High pressure lager yeast very difficult to clear had to as well as cold crash use gelatin and then Super F finings. I didn't have this issue with the kveik yeast or a Marzen ( using saflager yeast that I started warm at 20C under pressure and then left in 10c for 4 months).

 

[DVCNick]

My first time doing this was with S-23. I pushed the pressure up to 15psi with bottle gas at pitch time and fermented at 68, and it looked done in well under a week and I was drinking it in under 3 weeks as I recall.

I just did another batch, this time with 34/70 and let the pressure free rise to 15 psi. 68 degrees. Took 24 hours to naturally hit the pressure (and that is with lots of headspace). Fermentation looked visibly done in about 4 days. It's now been 9 days, if my kegerator wasn't full already it would be in there finishing carbing now.

So far so good for me.

 

[crazyjake19]

I have also heard that fermenting under pressure at room temperature can yield clean tasting lager.

Question about WLP925. I have one old keg in storage and I'm planning to try fermenting lager under pressure at room temperature in that keg. Haven't tried keg fermenting before and WLP925 is also yeast that I haven't used before. Any advice what should be taken into consideration while using WLP925 & keg fermenting?

I forgot about this thread for several months, but I've been using the same WLP925 (overbuild & harvest from my starters), and have been having continued success with it. I brew 4.25 gallon batches so I can ferment in either corny kegs or cheap 5 gallon FG buckets, so the batch size works out well for keg fermenting. I typically ferment around 62-65F in the corny keg, initially pressurized to around 14psi as soon as it's in the keg. This may not be necessary, as I've heard of other people just letting fermentation build up the pressure until their spunding valve starting venting off the excess around 14-15psi.

I let it ferment for one week at 62-65F (basement temperature for me), and I've always reached my final gravity after one week. Fermentation is most active 2-4 days after pitching; by day 6 there's no longer any excess pressure above 15psi being vented by my spunding valve. Then I move the keg to the keezer (~36F) for about 5 days (White Labs says "lager 3-5 days at 35F). Then I either serve right from the fermenter keg with a floating dip tube, or if I plan on transporting the keg I'll transfer it to a clean serving keg right inside the keezer (less lifting of full kegs).

In all the beers I've done this way, I've had a clean, clean beer into the glass at 14-15 days from brewing. I haven't tried fermenting under pressure with any other yeasts, but I may try some WLP820 under pressure for my next Octoberfest and compare the results to WLP925. My use of WLP925 started when I needed to come up with a keg of Octoberfest (which I called OctoberFast) in less than 3 weeks, and I've been using it since then mostly for Octoberfests and light lagers.

 

[VikeMan]

What, exactly, has been the experience of people pressure fermenting here?
The most authoritative thing I've seen is the podcast with White and blichmann where they say they were serving pressure fermented bier in two weeks. This seem to point to a pretty short lager fermentation time.

I could cold ferment (non pressurized) a lager and force carb it in two weeks. But I don't.

 

[The M]

crazyjake19 Thanks for your reply. Since my last post to this thread I have done one lager, two pils and one california common. Sounds that we have very similar techniques. I also overbuild & harvest from my starters and I've used 5gal kegs with spunding valve. The fermentation temp has also been between 62-65F but for some reason for me it takes at least 7 days to hit the FG. The rest of the process is similar. I have "lagered" the brew for 3-5 days and either served the beer straight from the fermenter keg or transferred the beer to the serving keg. WLP925 is a great yeast and very easy to work with. Clean lager/pils in no time

 

[ba-brewer]

Not much information on the whitelabs site regarding the flavor of WLP925, could someone comment if the flavor profile is like some other well know yeast.

 

[Beenym88]

I recently did a cheater version of a Pilsner with lutra yeast it came out crisp and super clear. Unfortunately I strayed from traditional hops and used motuka hoping to get a line flavor and really didn’t like it.

 

[kwmystra98]

I have also heard that fermenting under pressure at room temperature can yield clean tasting lager.

Question about WLP925. I have one old keg in storage and I'm planning to try fermenting lager under pressure at room temperature in that keg. Haven't tried keg fermenting before and WLP925 is also yeast that I haven't used before. Any advice what should be taken into consideration while using WLP925 & keg fermenting?

If you transfer to another keg it should be great. Otherwise you will keep the trub? The fermzilla all rounder is inexpensive and works great. I made a yuengling for my nephew when he visited and absolutely loved it. Said it was better than the store beer.

 

[Flamewhisperer]

I'd forgotten that I'd replied to this. I guess I didn't know. If you ask me though, fermenting at the cooler temps is easier than establishing the pressure in the first place, but if you've already got the equipment have at it. Can this be done in a corny? And do you apply CO2 to get the pressure?

I do pressure fermentation of a pilsner in a corny keg with a bowtie spunding valve set to 10 psi attached to the gas input to regulate the pressure created by the fermentation. I control the temp in a kegerator at 52°F. After attenuation I use a CO2 tank to push it through a filter into a second keg leaving the yeast behind for a crystal clear pour.

 

[Unicorn_Platypus]

When fermenting under pressure do you set the headspace to the desired pressure at the start of fermentation via a CO2 tank?

I'm planning to do my first pressure ferment with 34/70 at ambient temp ~70F-75F @ 20 PSI

Doing this in a keg at a friend's place who doesn't have temp control

Is 20 PSI too high? Ideally I want the thing fully carbonated and 15 PSI @ 70F seems too low

 

[Broothru]

When fermenting under pressure do you set the headspace to the desired pressure at the start of fermentation via a CO2 tank?

I'm planning to do my first pressure ferment with 34/70 at ambient temp ~70F-75F @ 20 PSI

Doing this in a keg at a friend's place who doesn't have temp control

Is 20 PSI too high? Ideally I want the thing fully carbonated and 15 PSI @ 70F seems too low

There are different methods. Some ‘cap’ in initial fermentation at 5 psi, either with bottled CO2 or by allowing pressure to build naturally from active fermentation but set to release via spunding valve at 5 psi. After a few days, reset the spund to release at a higher pressure like 15 psi.

After fermentation (at say, room temperature) when you’re ready to cold crash, the pressure in the keg will drop, so you’ll have to compensate with CO2 either from a CO2 bottle or from continued fermentation in the keg. The trick is to start chilling (or fermenting under pressure while chilling at a temperature maybe in the 38-45F range).

You’re correct that a 15 psi beer @ 75F would be way under carbonated.

 

[Unicorn_Platypus]

Anh

There are different methods. Some ‘cap’ in initial fermentation at 5 psi, either with bottled CO2 or by allowing pressure to build naturally from active fermentation but set to release via spunding valve at 5 psi. After a few days, reset the spund to release at a higher pressure like 15 psi.

After fermentation (at say, room temperature) when you’re ready to cold crash, the pressure in the keg will drop, so you’ll have to compensate with CO2 either from a CO2 bottle or from continued fermentation in the keg. The trick is to start chilling (or fermenting under pressure while chilling at a temperature maybe in the 38-45F range).

You’re correct that a 15 psi beer @ 75F would be way under carbonated.

Any harm at just pressurizing at 20 PSI from the get go and letting it ride?

Its gonna be at a friends house who is a novice with kegs. So just pressurizing to 20 PSI leaving it for about a week and then picking it up is my tentative plan. Don't want to confuse him by having him adjust pressure along the way. I'll set the valve to 20 and call it a day

Lets see what happens!

I am also planning to make a starter, oxygenate with a wand before pressurized so there should be plenty of disolved O2 for the yeast. I know starters aren't needed with dry yeast, but I like to do it to reduce lag time.

 

[Broothru]

Pressure fermenting at 30 would probably be too high. You could start out right at 15 psi (roughly 1BAR) and just let it ride all the way to completion. Then when you get ready to cold crash, just hook up a CO2 bottle with the regulator set at 15 psig and it will maintain pressure as the temperature drops.

When you’re through lagering/conditioning you’ll have properly carbonated beer, ready to serve immediately. You’ll probably have to dump the first 2-3 glasses because they’ll likely have a lot of settled yeast and other gunk, especially if you don’t have a floating dip tube arrangement on your keg, but after that you’ll be pouring great beer!

 

[Unicorn_Platypus]

Pressure fermenting at 30 would probably be too high. You could start out right at 15 psi (roughly 1BAR) and just let it ride all the way to completion. Then when you get ready to cold crash, just hook up a CO2 bottle with the regulator set at 15 psig and it will maintain pressure as the temperature drops.

When you’re through lagering/conditioning you’ll have properly carbonated beer, ready to serve immediately. You’ll probably have to dump the first 2-3 glasses because they’ll likely have a lot of settled yeast and other gunk, especially if you don’t have a floating dip tube arrangement on your keg, but after that you’ll be pouring great beer!

Lately I've been in the habit of priming all my kegs with sugar and never leave my CO2 connected even during lagering because they are already fully carbonated when I chuck em in the keezer.

For this particularly experiment keeping it connected for a week or two during lagering like you suggested makes sense. I have CBDS floating diptubes in all kegs so no worries about gunk

Whats the harm of going slightly above 1 bar to 20 PSI?

 

[Broothru]

Pressurized fermentation works by suppressing the development of undesirable esters and the subsequent flavor/aromas that yeast produce when fermenting at higher temperatures.

But not all esters produce flavors/aromas that are undesirable. That’s how you can get decent lagers, even when fermenting at temperatures in the mid-to-high 60sF instead of the low 40sF.

Different yeasts behave differently and produce a wide range of esters, flavors and aromas depending mostly on the temperature of fermentation and to a lesser extent on pressure, but the two factors are interrelated.

Also, safety related concerns become greater at higher pressures. The mechanical forces created by volumetric pressure increases follow ‘area squared’ rules. And subsequent stresses on tanks, valves, transfer lines, etc., don’t double from 15 psig to 30 psig, but rather increase logarithmically.

Plus, why would you ever want your beer to be carbonated to 30 psi? You’d have to spend days to get it stabilized down to serving pressure.

15 psi is a good compromise pressure to ferment beer. Most yeasts will work at 15 psig @ 60F, though it’s good to listen to anecdotal reports from fellow brewers as to their successes, or failures, using different yeasts.

Depending on your goals, I can highly recommend NovaLager dry yeast for a wide range of lagers and ales, although it was developed specifically to be a lager yeast used at higher ambient temperatures (60sF-70sF), and not necessarily for pressurized fermentation. But my experience in nearly half a dozen different fermentations is that it works equally well unpressurized as well as pressurized.

If you like liquid yeasts, I’ve also used White Labs WLP-808 “Mythical Hammer” which was specifically designed for pressurized fermentation, and it performs quite nicely at 1BAR pressure in lagers, but I’ve not tried it in an ale yet.

Just be mindful of the necessary precautions associated with pressurized fluids. A ruptured tank or blown fitting can ruin your whole day. Even though that Cornelius keg was rated at 60 psi pressure, that was certified on the day it was manufactured. Who knows how many pressurized/depressurized cycles it has been subjected to over its lifetime of use, or how many times it was dropped or dented due to mishandling, compromising its integrity? Those stresses are cumulative. No need to tease the animals.