fermenting under pressure Questions

[Arbe0]

I am getting ready to ferment under pressure with a keg but have a few questions first.
1) What kind of beers do best and worst for fermenting under pressure?
2) when fermenting under pressure with lagers do I ferment at 50 F like I normally do, or leave it at room temp (67 f)?
3) Is there a yeast that doesn't work well with pressure fermentation?
4) I have seen where people don't put a spunding valve on until 24 hrs. Is this correct?

 

[Yesfan]

Check out some related videos on YouTube from users like Short Circuited Brewers, David Heath Homebrew, and The Apartment Brewer. Some of them go in depth and even do a comparison of pressure vs non pressure (Apartment Brewer).

Certain yeasts like Belgiums I wouldn't want to pressure ferment. That might take away the ester profile. I plan on doing a lager in a ball lock corny keg. Just got to find the time to brew (if that ever happens...).

 

[SanPancho]

1- beers where you want very clean results, little to no ester character
2- you can do either.
3- hefe and other wheats can have trouble, some saisons report trouble as well
4- up to you. generally if you keep it under 7-10psi it isnt considered to inhibit growth of yeast, so that's what i do initially, then ramp it up to 20-30 after a day or so. or you can do a double pitch and spund from the get-go.

 

[Jag75]

https://www.kegland.com.au/blog/post/a-comprehensive-guide-to-pressure-fermentation

 

[Mutant]

I keep it simple. I ferment in kegs. I had my son build a couple of handfuls of pressure relief valves that are roughly 13 psi by using a thinner spring. I picked up a long length of thinner spring material. He determined the proper length and built a bunch. It works fine. Want a different pressure, just change the length of the spring. Much cheaper option when you are fermenting multiple kegs at a time. I typically brew to ferment in multiples of three kegs at a time. The most I've had fermenting at once was six kegs.

 

[odie]

everyone pressure ferments a little different.

typically, ales are best without any pressure initially. yeast "expression" for lack of a better term is what you want. especially hefe and saision types.

lagers are usually clean and crisp tasting so low/moderate pressure from the beginning is fine. either at larger temps or ale temps.

 

[beersk]

Bringing this back...

I have a question for those who pressure ferment - Is there a reason I shouldn't use yeast from a pressure fermented batch for a batch to be non-pressure fermented?

 

[stealthfixr]

Bringing this back...

I have a question for those who pressure ferment - Is there a reason I shouldn't use yeast from a pressure fermented batch for a batch to be non-pressure fermented?

I have done this many times with no problems. Vitality and Volume are important, the former often being low if you dump/pitch yeast after cold crashing. I now dump into an Erlenmeyer flask and then add 1 can of Proper starter on a stir plate for 8-ish hours to ensure it is also active before re-pitching. This is especially useful if the captured yeast sits in the fridge for any amount of time before re-pitch.

More to your question, if the yeast tolerates pressurization to begin with (i.e. did it get to FG?), I don't think re-pitching it is a problem.

 

[beersk]

I have done this many times with no problems. Vitality and Volume are important, the former often being low if you dump/pitch yeast after cold crashing. I now dump into an Erlenmeyer flask and then add 1 can of Proper starter on a stir plate for 8-ish hours to ensure it is also active before re-pitching. This is especially useful if the captured yeast sits in the fridge for any amount of time before re-pitch.

More to your question, if the yeast tolerates pressurization to begin with (i.e. did it get to FG?), I don't think re-pitching it is a problem.

Why would cold crashing reduce its vitality? It would happen if you harvested in a jar and pitched 1-7 days after as well. It'll only have been cold crashed for about 2 days, should I decide to brew tomorrow after work. And yes, it did reach the expected FG.

 

[odie]

Bringing this back...

I have a question for those who pressure ferment - Is there a reason I shouldn't use yeast from a pressure fermented batch for a batch to be non-pressure fermented?

I can't see any reason there would be any difference in the harvested yeast.

Just use an appropriate amount of yeast cake or slurry.

 

[beersk]

Thanks, guys. The beer cold crashing now is a 3.5 gallon batch of Mexi lager that fermented at 60F at about 22PSI and I'm thinking to step up and brew 5 gallons of my dark Mexi lager which I brewed back in the fall and absolutely loved. Not pressure fermented (or even low o2 brewed!) but was one of my all time favorite beers I've brewed. Can't decide if I want to do a big batch or try and see if it's any different with the smaller pressure fermented process I use.
Downside to having two processes (big and a small batch) is that there's always the constant struggle to decide which to use...

 

[Red over White]

The only thing I would recommend is to slowly de-pressurize the yeast to be repitched. Pulling the prv after you keg the previous batch certainly has to be a stressor, just as increasing pressure is the other way.

 

[beersk]

The only thing I would recommend is to slowly de-pressurize the yeast to be repitched. Pulling the prv after you keg the previous batch certainly has to be a stressor, just as increasing pressure is the other way.

See, this is what I was wondering about. Would the yeast be more stressed and therefore less healthy because of the pressurized fermentation, especially at 1.5 bar for full carbonation...?

 

[Red over White]

The pros repitch yeast from CCVs that have had up to 1 bar hydrostatic pressure on them, not counting head pressure without any problems. I have gone 4 generations without any issues. I add goferm protect evolution at flameout on a repitch to give the yeast every advantage available and slowly take pressure from the fermenter over the course of 4-6 hours to let the yeast slowly acclimate. I don't think you will be disappointed with repitching part of your yeast cake.

 

[beersk]

The pros repitch yeast from CCVs that have had up to 1 bar hydrostatic pressure on them, not counting head pressure without any problems. I have gone 4 generations without any issues. I add goferm protect evolution at flameout on a repitch to give the yeast every advantage available and slowly take pressure from the fermenter over the course of 4-6 hours to let the yeast slowly acclimate. I don't think you will be disappointed with repitching part of your yeast cake.

Thanks for the info.

 

[Yesfan]

Why would cold crashing reduce its vitality? It would happen if you harvested in a jar and pitched 1-7 days after as well. It'll only have been cold crashed for about 2 days, should I decide to brew tomorrow after work. And yes, it did reach the expected FG.

This past batch I did, I pitched the yeast cake from my All Rounder into my 15 gallon corny. The All Rounder sat at room temps between kegging and repitching (8 days between brews). I pitched the cake into the corny around 6pm last night. This morning, when I got up it sounded like a Harley idling. The yeast is US-05.

Chugging right along at 75F with the spunding valve at 15psi.

 

[beersk]

This past batch I did, I pitched the yeast cake from my All Rounder into my 15 gallon corny. The All Rounder sat at room temps between kegging and repitching (8 days between brews). I pitched the cake into the corny around 6pm last night. This morning, when I got up it sounded like a Harley idling. The yeast is US-05.

Chugging right along at 75F with the spunding valve at 15psi.

It sat at room temp for 8 days? Even under pressure I wouldn't think to do that... The beer I pitched into (dark Mexi lager, non-pressure fermented) from the pressure fermented batch fermented really well. If the Tilt is to be believed, it's currently at 1.011 after 5 days. But Tilts are horribly inaccurate nearing the end of fermentation, so there's no telling what the gravity is at. I won't know until I go to keg it in a week or so. The main thing will be how it tastes, was the yeast stressed from being pressure fermented and will create off flavors, etc. We'll see...

 

[Yesfan]

It sat at room temp for 8 days? Even under pressure I wouldn't think to do that... The beer I pitched into (dark Mexi lager, non-pressure fermented) from the pressure fermented batch fermented really well. If the Tilt is to be believed, it's currently at 1.011 after 5 days. But Tilts are horribly inaccurate nearing the end of fermentation, so there's no telling what the gravity is at. I won't know until I go to keg it in a week or so. The main thing will be how it tastes, was the yeast stressed from being pressure fermented and will create off flavors, etc. We'll see...

I don't have the room to chill my All Rounder due to its size. I've gotten a lot of older ingredients I'm trying to use up, so if this beer is a dumper no problem.

In the past, I've gotten Wyeast 1056 in the mail where the pack was pretty swollen from the heat during travel. Despite a few days in a hot UPS truck, that beer turned out decent.

 

[beersk]

I don't have the room to chill my All Rounder due to its size. I've gotten a lot of older ingredients I'm trying to use up, so if this beer is a dumper no problem.

In the past, I've gotten Wyeast 1056 in the mail where the pack was pretty swollen from the heat during travel. Despite a few days in a hot UPS truck, that beer turned out decent.

Gotcha. This is why my pressure fermented batches are all 3.5 gallons (2.5 gallon keg full) because fermenting in a 5 gallon keg is super awesome and easy. I really wish I could do this for 5 gallon batches but I don't have the capacity (kettle or fermentation). The beers just turn out so much freakin' better.

I don't order liquid yeast in the summer months for that very reason. Pretty much spring and fall when the temps are around 40-50F, no warmer.