Fermenting Under Pressure

[razz]

I set mine up to blow out into a 9lt corny Dave, but it never built up enough foam. Even when I was cleaning the kegmenter after use I noticed there was no krausen stains under the dome top. I did pitch a lot of yeast so maybe it didn't work that hard. I put it down to the pressure.

 

[Gloveski]

Any of you guys harvesting yeast, if you indeed can, from the blow off, or pitching straight back onto the cake?
Or does the whole process knock them around to much for another few rounds.

I've done two lagers pitched on to a yeast cake . Drinking one know and it was awesome

 

[Mardoo]

According to the research Ive read you start to see degradation in yeast health for fermenting at 30 psi or higher.

I’ve started messing with fermenting in a keg with a full-length tube, and transferring to another keg with a short dip tube for cold crash or dry hop. I leave a couple litres of wort in the fermenting keg. Then I give the fermenting keg a solid shake. Then I take off a couple bottles of wort as mtb said and let them settle out.

 

[Gloveski]

I've tried to ferment mine at about 11 psi . No signs of issues so far 6 brews in . Experimenting next batch I'll be pitching on to a yeast cake that will be about 20 days old and left at 2 degrees under pressure . More from necessity as I would have brewed Monday put pulled a hammy Saturday playing cricket . Second one this season , it seemed a great idea to come out of retirement at 43 . Also working 7 on 7 off so my normal brewing regime has been thrown out the window some what

 

[bradsbrew]

I have found that if I do not use oxygen the beers tend to under attenuate up to 10 points. I thought it must be to much pressure? But I can ferment at the same pressure after using oxygen and they attenuate very close to expected. Maybe it's because it was the 4th gen of slurry all pressure fermented? I generally have 5 cubes from each batch so it's not due to different batches. Having said that the last one started at 1070 and ended at 1024. I added around 30% water to bring it back down to 1014 and it's a cracker. Next batch will be using oxygen, so it will be interesting to see the outcome now that I am taking notes.

Cheers

 

[Gloveski]

I've read so much on homebrewing for everyone that says pitching on a yeast cake is over pitching another says it not an issue at the homebrew level . I've got to the stage were I'm experimenting myself and my own tastebuds will decide

 

[Gloveski]

I have found that if I do not use oxygen the beers tend to under attenuate up to 10 points. I thought it must be to much pressure? But I can ferment at the same pressure after using oxygen and they attenuate very close to expected. Maybe it's because it was the 4th gen of slurry all pressure fermented? I generally have 5 cubes from each batch so it's not due to different batches. Having said that the last one started at 1070 and ended at 1024. I added around 30% water to bring it back down to 1014 and it's a cracker. Next batch will be using oxygen, so it will be interesting to see the outcome now that I am taking notes.

Cheers

Interesting oxygen is one area I haven't ventured down as yet , more for the fact of the money I have spent on everything else at this stage . But I've had no attenuation issues as yet but only 6 brews in under pressure

 

[Mardoo]

I’ve been using the Vitality Starter method with no pure O2 and haven’t had any attenuation issues. However, that’s technically an oxygenation method. I’m hoping to try it with pure O2 soon. I haven’t tried no oxygenation at all.

 

[Mall]

I've now done 6 brews under pressure in a 50L keg, 40L batch. Quality has improved another level, hop presence remains, and spear not altered at all, using a coupler with ball lock connects.

Once I fill my 2 corny kegs to go into kegerator for serving, I transfer (CO2) a PET bottle full of bolied/cooled water to mix with the yeast then push yeast out into the Pet bottle. After that the usual rinsing and labelling for next batch.

 

[Dave70]

According to the research Ive read you start to see degradation in yeast health for fermenting at 30 psi or higher.

I’ve started messing with fermenting in a keg with a full-length tube, and transferring to another keg with a short dip tube for cold crash or dry hop. I leave a couple litres of wort in the fermenting keg. Then I give the fermenting keg a solid shake. Then I take off a couple bottles of wort as mtb said and let them settle out.

Along those lines (sort of..) I was thinking of tig welding an extra couple 15mm stainless nipples into the top of the keg and having a specific disconnect for each stage - 1 - long tube for the yeast collection (perhaps fit with a ball valve to avoid ******* cloggage) - 2 - Short tube with screen for the beer - 3 - regular short for blowoff - 4 - shortened short for spunding valve.
Though considering I've yet to brew a single beer under pressure, I may be getting carried away..

 

[pcqypcqy]

Enough to know it pours perfectly fine when force carbing a keg at 300kpa for 24hrs.

Fair enough. All I can say is have very few issues transferring and then serving immediately with my keezer gear (either taps or Pluto).

The only time I have had issues is when I get hop matter clogged in poppet, or hop socks jammed in the end of the dip tube. But if you've transferred already with no issues, then not sure that helps explain it.

 

[Mardoo]

Along those lines (sort of..) I was thinking of tig welding an extra couple 15mm stainless nipples into the top of the keg and having a specific disconnect for each stage - 1 - long tube for the yeast collection (perhaps fit with a ball valve to avoid ******* cloggage) - 2 - Short tube with screen for the beer - 3 - regular short for blowoff - 4 - shortened short for spunding valve.
Though considering I've yet to brew a single beer under pressure, I may be getting carried away..

Yep, probably not enough experience with PF yet to build one for yourself. Build one for me instead

 

[Crusty]

Fair enough. All I can say is have very few issues transferring and then serving immediately with my keezer gear (either taps or Pluto).

The only time I have had issues is when I get hop matter clogged in poppet, or hop socks jammed in the end of the dip tube. But if you've transferred already with no issues, then not sure that helps explain it.

I think 26psi @18deg for 48hrs must of over carbed it.
I'll have to look at a bit less pressure next time & let the Co2 bottle pick up the slack @serving pressure.
I didn't transfer mine, I'm drinking it straight from the 50L keg / fermenter.

 

[Dan Pratt]

Video of my current batch of IPA #stupidegoIPA

 

[pcqypcqy]

I think 26psi @18deg for 48hrs must of over carbed it.
I'll have to look at a bit less pressure next time & let the Co2 bottle pick up the slack @serving pressure.
I didn't transfer mine, I'm drinking it straight from the 50L keg / fermenter.

18 degrees and 26 psi should be 2.4 volumes, so you should be ok.


I'd have a look in your pick up tube, it may be clogged with hops, hop sock, yeast, whatever.

 

[Crusty]

18 degrees and 26 psi should be 2.4 volumes, so you should be ok.


I'd have a look in your pick up tube, it may be clogged with hops, hop sock, yeast, whatever.

Nothing in there.
Serving from a 50L commercial keg.
It's over carbed for sure.

 

[pcqypcqy]

Nothing in there.
Serving from a 50L commercial keg.
It's over carbed for sure.

Can you put a spunding valve on it and measure the pressure it's at now, along with the temp?

2.4 volumes shouldnt be overcarbed at all.

 

[Lionman]

Does anyone know for sure what style coupler this will take?

Edit: Pretty sure its a Type S?

 

[bradsbrew]

Along those lines (sort of..) I was thinking of tig welding an extra couple 15mm stainless nipples into the top of the keg and having a specific disconnect for each stage - 1 - long tube for the yeast collection (perhaps fit with a ball valve to avoid ******* cloggage) - 2 - Short tube with screen for the beer - 3 - regular short for blowoff - 4 - shortened short for spunding valve.
Though considering I've yet to brew a single beer under pressure, I may be getting carried away..

I would seriously suggest making #2 a KK floating pick up, they work very well and the clearest beer is always at the top. I have two 23 L myton rod kegs that i have been using for PF as well as the Fsaurus. I am getting float pick ups for the MR kegs. You can still keep #1, when transfer to keg has finished, give the FV a swirl to mix the yeast and left of beer, then send from the pick up to a settling flask.

 

[Coldspace]

I've read that article and it says over 2 atm pressure , so I'd say above 30 psi is bad.

I've always still pitched yeast starters or appropriate amount of dry yeast to style, oxygen added, and run the primary ferment in the middle of temp range of yeast with usual rises towards the end and carb up. Never tried higher temps as it's working for me so don't want to try and fix something that's not broke as they say.

One day if I could be arsed , I've got 3 kegmenters , should try a ghetto brulosphy xperiment lol and try diff temps. Na.

I run mine between 10-14 depending on how accurate my spunding valves are on the day.

Pressure rise at end to low 20s for carb up and it's when the yeast is 95% done it's job anyway.

Ales, stouts, reds are all great, just run mid ferment pressures under 1 ATM , and keep final pressures in check with the style, keep slightly under if unsure. But this method was obvious designed for lagers, but I do all my brewing now this way with great success , plus added benifits of full closed systems, and natural carb mouth feel, etc.

Plus it looks cool

All my beers, about 30 plus pressure ferments down now have gone great.

Yes, too high finish pressure can cause over carb, so can a lower pressure say 26 psi with a bigger volume headspace cause over carb on cc due to the volume of co2 compared to volume of liquid in the keg, It's done this for me on a few occasions in my early batches.

This is just my findings from batch to batch, but maybe some of the more technical guys here could add to this about pressures, temps, volumes etc etc..

So, keep in mind guys, till you get to know your systems , go slightly easier on the final end pressures especially if you have a bigger headspace in the keg and if under carbed , top up from gas bottle.
Easier than over carb beers.

I have my 3 kegmenters dialed in great now and every second batch or so, only needs a 30 psi squirt or 2 over 24 hrs to bring perfect. Some great from the start.

Cheers