Fermenting Under Pressure

[Crusty]

I've posted some results of my first pressure ferment over in the spunding valve thread.
I am now drinking, directly from the fermenter, a St.Loius Lager that was brewed 12 days ago & now on day 3 of a 2deg Lagering stint. I was initially looking to do a 3 week Lager but this beer is fantastic, it's bloody liquid gold. You would swear it's been Lagering for weeks. The natural carbonation has put a real commercial spin on this beer & I'm really stoked I brewed 45L of it. I was initially going to transfer to a serving keg but I'm not going to bother. It needs a week or so at Lagering temps to clear but that aside, it's an absolute cracker.

 

[Mardoo]

When you dry hop mate and transfer are you then using this as your serving keg ? If you transfer again are you loosing any aroma from the spunding valve venting during transfer on the receiving keg

No, I always transfer off the dry hop to a serving keg to allow any fine particulate to settle out.

I transfer without the spunding valve on either the source or the receiving keg. I'm attaching my gas bottle to the source keg gas in, and then connect the liquid posts. As the receiving keg is vented to drop the pressure below the source keg, there is some aroma that comes out, but it's pretty minimal. Frankly, I think the amount of aroma that could be lost by doing this would be undetectable by anyone drinking the beer, but then, I haven't done any sort of side-by-side comparison. When I'm trying hard to keep all the hoppy goodness in a beer, it's usually very, very hoppy, so would guess it has a bit of aroma to spare.

Does that answer your question?

Interesting question. I spent last night geeking hard about vegetal hop flavours and roast malts, so my brain is a bit fried. Hope that answer helps.

 

[Gloveski]

No, I always transfer off the dry hop to a serving keg to allow any fine particulate to settle out.

I transfer without the spunding valve on either the source or the receiving keg. I'm attaching my gas bottle to the source keg gas in, and then connect the liquid posts. As the receiving keg is vented to drop the pressure below the source keg, there is some aroma that comes out, but it's pretty minimal. Frankly, I think the amount of aroma that could be lost by doing this would be undetectable by anyone drinking the beer, but then, I haven't done any sort of side-by-side comparison. When I'm trying hard to keep all the hoppy goodness in a beer, it's usually very, very hoppy, so would guess it has a bit of aroma to spare.

Does that answer your question?

Interesting question. I spent last night geeking hard about vegetal hop flavours and roast malts, so my brain is a bit fried. Hope that answer helps.

Awesome mate cheers for this , my next brew will be dry hopping so just looking at different techniques to try

 

[manticle]

I ferment in 19L kegs filled to the top. I connect a line from the gas post (I cut the dip tube down so it doesn't protrude into the keg) to the liquid post of a mini keg and attach the spunding valve to the gas post of the mini keg. I have done quite a few batches like this and most I lose in blow off is a few hundred mls. When I transfer to the serving keg it pretty much fills it up. Beer comes out of the pressure relief valve at the same tim the fermenter starts suckking gas. I put a tee on the blow off so i can have two kegs fermenting into one blow off.

The kegs I ferment in are not cornies though, they are chinese kegs I picked up cheapish and I think they hold a little more than a cornie.

I don't bother with adding chemicals to beer. Water+Grain+Hops+Yeast.

H2O + C12H22O11+ 3,4-Dihydroxy-5-(3-methylbut- 2-enyl)-2-(3-methyl-1-oxobutyl)-4-(4- methyl-1-oxopent-3-enyl)-1- cyclopent-2-enone+ Saccharomyces cerevisae in order to produce C2H5OH and various byproducts and waste material including polypeptides and saccharides.

I love chemicals in my beer.

 

[mtb]

H2O + C12H22O11+ 3,4-Dihydroxy-5-(3-methylbut- 2-enyl)-2-(3-methyl-1-oxobutyl)-4-(4- methyl-1-oxopent-3-enyl)-1- cyclopent-2-enone+ Saccharomyces cerevisae in order to produce C2H5OH and various byproducts and waste material including polypeptides and saccharides.

I love chemicals in my beer.

Showoff.

 

[manticle]

To be honest, most of it was google + Ctrl+v.

Principle remains.

To be slightly on topic, this thread has made me reconsider fermenting in a corny (something I tried a few years ago - nc, ferment, dispense from single vessel). With a few alterations to my original plan I reckon I could make it work.

 

[RobB]

To be honest, most of it was google + Ctrl+v.

Principle remains.

To be slightly on topic, this thread has made me reconsider fermenting in a corny (something I tried a few years ago - nc, ferment, dispense from single vessel). With a few alterations to my original plan I reckon I could make it work.

I was just thinking the same thing. I brew smaller batches than most people and serve from 12 litre kegs, so for me a normal cornie keg would be a kegmenter with loads of head space. I typically brew under 6% abv and empty a keg within about 5 weeks, so I'm wondering if I could just use a floating dip tube and serve straight out of the kegmenter. The yeast would be 8 weeks old by the time I poured the last glass (2 weeks fermenting, 1 week crashing/settling and 5 weeks serving) - do you think I would get away with it?

 

[RobB]

duplicate post deleted

 

[manticle]

My original plan relied on being able to suck the bulk of primary yeast out via dip tube when ready. The whole thing working is contingent on that.

 

[Gloveski]

My original plan relied on being able to suck the bulk of primary yeast out via dip tube when ready. The whole thing working is contingent on that.

Is that so you can harvest the yeast mate ?

 

[Gloveski]

I was just thinking the same thing. I brew smaller batches than most people and serve from 12 litre kegs, so for me a normal cornie keg would be a kegmenter with loads of head space. I typically brew under 6% abv and empty a keg within about 5 weeks, so I'm wondering if I could just use a floating dip tube and serve straight out of the kegmenter. The yeast would be 8 weeks old by the time I poured the last glass (2 weeks fermenting, 1 week crashing/settling and 5 weeks serving) - do you think I would get away with it?

I done two pressure transfers using the keg king floating dip tubes and they worked great , left me basically with just the cake . So should be fine to use as a serving option aswell

 

[manticle]

No. I don't like keeping beer on primary for too long, certainly not after ferment has finished and I'm dispensing. Pro of nc into corny and ferment/dispense from same is reduction of transfer, (oxygen, number of vessels, etc) but exposure to trub has the potential to negate those benefits.

 

[Maximus Humulus Lupulus]

I think it was Vinnie Cilurzo from Russian River, but it may have been Stone, that commissioned a laboratory study about dry hopping and pellet suspension. It showed that pellets that suspend the longest have the highest transmission of hop flavour compounds. Having spent a fair bit of time packing hop pellets in a friend's business, there are major differences in pellet density between processors, from practically glassy through to almost spongy. Unfortunately, hop growers do not always have control over what sort of pellets the processors they use produce. However, I know that some of the new craft hops growers intentionally aim to produce a looser pellet. So in terms of suspension, you're on the right track. Can you bubble CO2 up through the hop and yeast mass from the bottom of the Fermentasaurus? That's the easiest way to re-suspend.

I can't speak to floatiness of pellets under pressure, because I ferment in a stainless pressure vessel. However I do re-suspend daily with a CO2 injection through the liquid out post, and a solid shake. I then re-equalise the pressure to my desired level. I usually ferment at 10psi, as I'm usually not looking for ester suppression.

Generally when I dry hop, rather than open the fermentation vessel I put the hops in another of my SS fermenters, purge, and transfer the beer through the liquid posts. I'm not always organised enough to have one of the fermenters ready, but try to be.

First of all, thanks for the suggestion about bubbling CO2 up from the bottom. I have rigged up a Heath Robinson contraption that allows me to do this, and having been put together by a man with the DIY skills of a bi-valve mollusc, I have to say it works surprisingly well. However, it did nothing to resuspend the hops, which instantly started to sink back to the bottom once bubbling ceased. (But at least they will have had more contact time as a result.)

Further investigation reveals that, as you allude to above, pellet density is indeed the culprit here. Since my post on 24.10.17 above I've dry-hopped two more brews, using T90 pellets from two different suppliers. In one brew, the Mosaic pellets were floaty as **** and took over three days to sink, whereas the Cascade pellets added to the other brew were suicidal little shits and immediately sank like stones. In both instances the pressure was 10-12psi.

This clip shows how pellets of different densities behave, and illustrates the phenomenon perfectly. All I need to do now is find out how I can source medium density pellets!

 

[Mardoo]

I believe the Crosby Farms ones are intentionally a bit less dense. HoweverI have yet to get some, so that’s just hearsay ATM. They’re available from a few places in OZ. I know Beerco stocks them, and I know I’ve seen them elsewhere, but can’t remember where else.

 

[MHB]

I wouldn't be too worried about the pellet density, in fact the tighter the better for mine (reduces oxygen penetration). The only thing that holds pellets together is the naturally occurring rosins and waxes in the hops, hop cones are ground to powder and then put through an extruder. The higher the pressure and the higher the amount of natural binders the tighter the pellets.
Shure the vid above looks convincing, but come back in half an hour and I strongly suspect you would be hard presses to tell the difference. Just go for the best hops you can get, look after them and enjoy.
Mark

 

[droid]

My first pressure ferment, thought bugger it might as well transfer a bit to a PET and cool down for a taste

 

[droid]

Sorry if it has been covered, does a warm pressure ferment mean that you can do a closed warm transfer to a bottle as above and then chill without issues? It would be nice to have a few kegs that are at cellar temp and carbed, allowing the odd bottle to be filled and chilled whenever as opposed to a whole keg having to be chilled..

 

[Danscraftbeer]

Sorry if it has been covered, does a warm pressure ferment mean that you can do a closed warm transfer to a bottle as above and then chill without issues? It would be nice to have a few kegs that are at cellar temp and carbed, allowing the odd bottle to be filled and chilled whenever as opposed to a whole keg having to be chilled..

Mini kegs are handy for that. Never tried to transfer into bottle when warm but i do transfer from kegmenter to serving keg when still warm and the trick is at higher pressure than the beer finished at to prevent foaming.
Eg my Tooths Pale Ale finished at 22psi so I set the co2 bottle at 30psi or higher is faster etc and the spunding valve on the receiving keg at ~at least 22psi. Fill by weight.

 

[Maheel]

what temps are you peeps fermenting ales at under pressure ?

i am still using +-17

droid do u have a 19'c shed...?

 

[droid]

what temps are you peeps fermenting ales at under pressure ?

i am still using +-17

droid do u have a 19'c shed...?

I'm doing 20 - it's South Eastern Gippsland, the temp in the shed hasn't gone over 20 for the last week, plus they are sitting on cold concrete. They both have heater belts as the drop in temp is the only concern here...at the mo