Pilsner, fermentation under pressure, temp and pressure?

[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.

 

[Bassman2003]

The amount of pressure is up to you. There is no harm in doing a 'single pressure' beer where you ferment at your end carbonation level. For lagers and IPAs it is quite nice. I will relay that I know brewers that have gone to using 3 bar as their SOP as they like the flavors so much. They just open up the spunding valve towards the end of fermentation to stabilize the volumes of CO2 to match their end serving carbonation.

For me, I always do my IPAs at 2 bar - 32PSI - 70-72F. It takes more yeast but the hops pop. At that temperature, that is not far off of where I want to serve at using 45F. For lager, a lot of guys I know will ferment from 1 -2 bar @ 50F. If you ferment a lager around 15 PSI @ 50F you are pretty much done. All natural carbonation and no oxygen or fuss. Remember, pressure fermenting is not just about being able to ferment warm. It is also about trying to mimic the very large CVVs in pro breweries.

Just remember to use a lot more yeast if you do this approach. I would say double your pitch rate for ales and triple for cold lagers under pressure.

 

[Unicorn_Platypus]

The amount of pressure is up to you. There is no harm in doing a 'single pressure' beer where you ferment at your end carbonation level. For lagers and IPAs it is quite nice. I will relay that I know brewers that have gone to using 3 bar as their SOP as they like the flavors so much. They just open up the spunding valve towards the end of fermentation to stabilize the volumes of CO2 to match their end serving carbonation.

Thanks for the great info!

Do you know what kind of spunding valves folks are using with springs that can go as high as 3 bar? The blowtie valves (most readily available to homebrewers) and I don't believe are recommended above 30 PSI. They say they go up to 40 PSI technically.

I had Trong who makes the spundit create a custom spunding valve for me that goes up to 80 PSI, but wondering what other folks use.

(P.S. I do mostly ales not under pressure, but prime in the kegs with sugar. Currently, I have a beer i dosed with Brett at kegging and I have the valve set at 40 PSI to prevent over carbonation)

For me, I always do my IPAs at 2 bar - 32PSI - 70-72F. It takes more yeast but the hops pop. At that temperature, that is not far off of where I want to serve at using 45F. For lager, a lot of guys I know will ferment from 1 -2 bar @ 50F. If you ferment a lager around 15 PSI @ 50F you are pretty much done. All natural carbonation and no oxygen or fuss. Remember, pressure fermenting is not just about being able to ferment warm. It is also about trying to mimic the very large CVVs in pro breweries.

Just remember to use a lot more yeast if you do this approach. I would say double your pitch rate for ales and triple for cold lagers under pressure.

More great info!

thanks for the advice, I generally make big starters for lagers and will keep this in mind for high pressure situations. This particular scenario won't have temperature control. I figure the ambient will be ~70-75F. Good to know you have had success with IPAs in this range at 2 bar / 32 PSI.

I'd prefer for the beer to be fully carbonated when I chuck it in the keezer. Typically, I never keep my CO2 connected unless I'm serving to mitigate O2 ingress and all my beers are naturally carbed.

Are you using the blowtie or a different spunding valve for 2 bar?

 

[Unicorn_Platypus]

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 degree 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.

Thanks for your thoughtful replies!

My standard practice nowadays is to naturally carbonate all my beers with priming sugar in the kegs at room temp ~70F. I chuck them in the keezer after pressure stabilizes for 48 hours in a row after spiking. Depending on the kinds of beer I'm doing, the kegs can get as high as 40 PSI at that temp to acheive desired level (Belgians get up to 40 PSI for 3 volumes, but most beers are at around 30 PSI for 2 volumes)

After chucking in the keezer, I lager all beers for 10 days @ 32F. This gives enough time for CO2 to fully dissolve, pressure to reach equilibrium, and for the beers to clear nicely.

I prefer to never keep my CO2 tank connected in between serving to mitigate O2 ingress. I also prefer natural carbonation to tank carbonation for low O2 reasons.

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.

I've actually got a pack of the Nova lager on hand that my homebrew club gave me. Haven't used it, but I'll give it a shot!

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.

I am an overly cautious person in general, and I appreciate the warning on that! That being said, all of my kegs are rated to 9 bar and they were all purchased brand new. I gave up on used soda kegs for various reasons including the concerns you mention. All of me beers hit 30 PSI in the kegs nowadays since I prime with sugar at room temp.

I would never consider going over 15 PSI in my fermzillas for example for the reasons you stated, but I believe I'm very safe at those higher working pressures with kegs rated to 9 bar

 

[Bassman2003]

The blowties are just a body with a screw that depresses a membrane. That part can handle a lot of pressure. It is the gauge part of the Blowties that limit their pressure rating. I have two different styles - the one that needs a "T" to add a gauge and the one that has a little square part that holds the gauge. The first one just depends on the gauge you add to determine the pressure. I have a 60 PSI gauge but have never gone over 40 PSI.

The confusing model is the Blowtie that most often sold as a 15 PSI spunding valve. If you pop the little square 15 PSI gauge out an replace it with their 60 PSI gauge it will be a 60 PSI spunding valve. This is not made very clear by Kegland. I changed it out for their digital gauge which is supposed to be very accurate and can go to 90 PSI.

Pressure fermentation is a really cool level you can pull in your brewing. There can be a place for it or you can skip it.

 

[Unicorn_Platypus]

The blowties are just a body with a screw that depresses a membrane. That part can handle a lot of pressure. It is the gauge part of the Blowties that limit their pressure rating. I have two different styles - the one that needs a "T" to add a gauge and the one that has a little square part that holds the gauge. The first one just depends on the gauge you add to determine the pressure. I have a 60 PSI gauge but have never gone over 40 PSI.

The confusing model is the Blowtie that most often sold as a 15 PSI spunding valve. If you pop the little square 15 PSI gauge out an replace it with their 60 PSI gauge it will be a 60 PSI spunding valve. This is not made very clear by Kegland. I changed it out for their digital gauge which is supposed to be very accurate and can go to 90 PSI.

Pressure fermentation is a really cool level you can pull in your brewing. There can be a place for it or you can skip it.

I thought that the spring in the blowtie spunding valve isn't intending for pressures above 30 PSI (kegland lists it as up to 40 psi) . I do have a high pressure gauge available I could hook up but my understanding is that you needed a different spring too.

What are the highest pressures have you used on the regular model (the one without a gauge)?

This is the model I'm talking about

 

[Bassman2003]

I think they have a version 1 and version 2. I have v2 and have a 60 PSI gauge on it. But I am unclear what the upper limit is. I have not gone above 40 PSI. I read the little one can go to 90 PSI.

Also remember, pressure fermenting in the end is all about volumes of CO2 in the beer. That is the only statistic that matters to the yeast. They do not care about the PSI but rather how much dissolved CO2 is around. The colder the temps the more CO2 that goes into concentration. So try to think of volumes of CO2 rather PSI when fermenting.

 

[Unicorn_Platypus]

I think they have a version 1 and version 2. I have v2 and have a 60 PSI gauge on it. But I am unclear what the upper limit is. I have not gone above 40 PSI. I read the little one can go to 90 PSI.

Also remember, pressure fermenting in the end is all about volumes of CO2 in the beer. That is the only statistic that matters to the yeast. They do not care about the PSI but rather how much dissolved CO2 is around. The colder the temps the more CO2 that goes into concentration. So try to think of volumes of CO2 rather PSI when fermenting.

Per kegland they're confirmed 40 PSI is not an issue