No chill in corny keg

[Florian]

You won't offend me at all. This kind of thing (pressure, etc)is not my strong point which is why I'm asking. I know that a cube will suck air in - just wasn't sure that if the keg was sealed and flushed with C02 whether that would still happen.

The idea mentioned above of attaching the disconnects to the posts (beer and gas) - would this prevent this or not?

Feel free to consider me a complete dunce in this regard - I am quite new to kegging and am interested in the viability of this method but am keen to learn from those who have tried it.

Not exactly sure what a dunce is so I won't call you one... I remember the time before I started kegging, it took me a while to get my head around this whole pressure thing as well.

If you just attach disconnects (and nothing else) to the post you will just freely suck air into your keg, as you have pretty much opened the posts by attaching the disconnects.

If you don't attach anything to the posts at all, you will still suck air in through either the posts or the PRV, whichever of the three springs in those is the weakest. If those springs were really strong you would most likely get dented keg walls, they would be sucked in like the walls of your plastic cube. But as suggested by others this is unlikely, so air will get sucked in instead.

If you now attach only one disconnect to the gas in post, you basically open that post up so air can get in freely to equalise the pressure in the keg with the air pressure outside of the keg. As you don't really want to suck your garage air into the keg, you can attach the sanitary filter via a piece of beer line, so at least the air that get's sucked in is 'clean'.

If you now wanted to store your wort for a longer period once it's cooled I would completely flush the headspace (containing Co2 and 'clean' air) with Co2 so that it only contains Co2.

EDIT: added quote

 

[manticle]

Cheers.

I meant disconnects attached to co2 cylinder and ploto gun. Most likely I'll just get meself one a them new fangled air filter things (or presumably two - one for each post?)

 

[manticle]

Manticle

I did exactly this recently. Primarily because I don't have any plastic cubes.

Sterilised the keg
Dumped from kettle (through hopback) into Corny - level was just underneath the gas in post
Lid on
Pressurised to ~ 1Bar (just to make sure lid was sealed)
Inverted keg for a few minutes - to make sure hot wort kills anything around the lid

Upped CO2 pressure to 3 BarG and pressurised keg

The next day the pressure in the keg was still positive - I just gave it a squirt of CO2 occasionally (at ~1.5 BarG) - I didn't want the Beer to be carbonated at this stage so was reluctant to leave it hooked up.

Worked a treat - I added to the fermenter through a sterile beer gun and pitched straight away.

I suggest a modified Liquid tube to avoid getting all the trub

Cons

Volume is low - ideally I want to ferment with ~22 L - so would need to use 2 cornys.

I also thought about chucking some hops in while it was still hot - I understand that No Chillers do this.

RM

Thanks for the response - so no trouble sucking air in? I don't mind the slightly reduced volume. Even thinking along the lines of what Bribie suggested - one shot with the pluto post fermentation to remove most of the yeast before transferring to another keg for dispensing.

This is the bit that is confusing me Florian. How does the air get sucked in if you have positive pressure in the headspace?

 

[surly]

Cheers.

I meant disconnects attached to co2 cylinder and ploto gun. Most likely I'll just get meself one a them new fangled air filter things (or presumably two - one for each post?)

Attached to CO2 and pluto SHOULD work.
If you attached your CO2 with pressure on (keep it at just above atmosphere), then the CO2 will force its way in when the pressure in the keg drops. You can ignore the liquid post then (or leave pluto attached).

If you were to attach the sanitary air filter, the theory is, there SHOULD be less resistance drawing the air through the filter into the keg than there would be in overcoming the spring loaded seal on the other post. Therefore, only clean air will be drawn in.


If you look at how the posts work, there is a centre piece with a rubber seal on it. This is held in the "sealed" position by a spring. If you increase pressure inside the keg, this centre piece is forced even more firmly against its seat and the seal gets stronger. However, this centre piece can easily be depressed (into the keg) via a finger or disconnect. You only have to overcome the power of the spring. So a vacuum inside the keg (caused by cooling wort) would easily suck air in against the spring.
You need to provide a path of less resistance, hence attaching the gas at just above atmosphere pressure, or the use of a sanitary filter.

Hope this makes sense?

 

[Florian]

Thanks for the response - so no trouble sucking air in? I don't mind the slightly reduced volume. Even thinking along the lines of what Bribie suggested - one shot with the pluto post fermentation to remove most of the yeast before transferring to another keg for dispensing.

This is the bit that is confusing me Florian. How does the air get sucked in if you have positive pressure in the headspace?

Ah, I think this is were the confusion might come from.

I was talking about just purging the head space with Co2, which is just like flushing the air out so to speak. Doesn't necessarily leave pressure in the keg.

You were talking about pressurising the keg, right? If you do that, like PF and RM suggested, then you won't need an air filter or whatever, assuming you put enough pressure in there to equalise the vacuum of the cooling wort.
This is probably the easiest method.

I guess the only concern with that could be that, if you put too much pressure on, that you're basically dissolving Co2 into your wort. Not sure how that could possibly affect fermentation, and I would definitely depressurise the keg while it's still fairly warm (before you pre chill wort to ferment temps) as this is when Co2 is dissolved the hardest and therefore leaves the wort the easiest.

That's why I liked PF's idea of pressurising with O2, as you're getting two birds with one stone if done right.

EDIT: added quote (again). Also, surly is on the money.

 

[surly]

Would there be an issue pressurising with O2? We ARE dealing with hot wort after all..

In theory, I think the easiest way would be connecting the CO2 up via a regulator at low pressure. You won't carbonate your wort, it is sanitary and there wouldn't be any concerns about oxygenation (maybe this is just MY concern..).
The drawback would be that you have dedicated that regulator to a low pressure task which might prevent you from serving your other beers..

 

[manticle]

Thankyou Surly - that explanation makes sense. Thanks too Florian.

Yes I was talking about pressurising the keg but like I say, my understanding of gas, pressure and displacement is not even rudimentary.

I would have concerns oxygenating hot wort.

 

[Florian]

Would there be an issue pressurising with O2? We ARE dealing with hot wort after all..

Do you mean in regards to hot side aeration or safety?

In theory, I think the easiest way would be connecting the CO2 up via a regulator at low pressure. You won't carbonate your wort, it is sanitary and there wouldn't be any concerns about oxygenation (maybe this is just MY concern..).
The drawback would be that you have dedicated that regulator to a low pressure task which might prevent you from serving your other beers..

Agree, that is probably the most feasible option, provided you can spare that Co2 bottle and reg.

I guess another positive about keg no chilling for the list is that you can easily force oxygenate your wort once it's cooled. Connect O2 tank to cooled corny at high pressure and shake, or leave connected until desired saturation level is reached.

 

[surly]

Hey Florian, my concern was for hot side aeration. Hadn't considered safety, though figure you would need a bit more than 100deg C for O2 to be particularly dangerous??

 

[manticle]

HSA would be my concern. I know it's not a massive issue on an HB scale and you really have to try hard to create an issue but oxygenating boiling hot wort would surely be pushing the limits.

Just before I go ahead and set myself up for this - no-one can see any way I can blow up myself or my kegs if attach the gas and ploto after filling and sealing the keg? I'd be having a crack at fermenting in the same keg as well - trying with the bleed nozzle raised for C02 release as when I ferment in cubes, I seem to get reduced krausen (presumably because the wort is under more pressure than in a fermenter with glad wrap). I'm hoping the gas bleed nozzle is enough. Can fit more kegs in my fridge than I can cubes.

 

[mckenry]

It's something I have been thinking about for a while, but dismissed in the end because of the amount of trub and the amount of head space required. I reckoned I'd only get about 13.5L of beer out if each corny. I'm thinking about trying to get 38L out if a 50L keg. That should be doable, but bloody heavy to move in and out of a ferment fridge if I don't get it set up right.

Sorry manticle. My thoughts above werent really what you were getting at (after reading the rest of this thread) I thought after reading Florians post you quoted, that you were going to ferment in the corny as well, as you do with your cubes. Thats why I said what I said.

 

[manticle]

Actually you're right - I am considering fermenting in them as well. If you read the thread about fermenting under pressure you'll see Krausen is reduced so headspace is less of a concern. I often fill my cubes right up and get some to no krausen leakage. While I'm not exactly fermenting under pressure, I wonder if the slower release (cap on, slightly turned to loose) affects the krausen in a similar way or whether it's to do with the shape of the vessel or a bit of both.

The yeast/trub could presumably be dealt with with either shortened dip tube (but then I need kegs designated only for that purpose) or simply by removing via beer outpost. Yeast can then be reserved for later use or discarded. Presumably you could dispense from the same keg too but I think I would prefer to transfer at that point.

Probably not a viable option for beers that require big starters as I use identical wort for my starters and add the entire lot when active but for things like my dark mild and UK bitters it might be a goer. I tend to make those more often than dark strongs or doppelbocks.

 

[wobbly]

Mantical

I know this is going of topic but seeing you are contemplating fermenting in the same corny after "no chilling" have a read of this thread I previously posted on the Pressure Fermenting topic http://www.homebrewtalk.com/f51/spunding-valve-commericial-style-diy-333907/ and you will see that they eventually concluded that it wasn't necessary to modify (shorten) the dip tube

Cheers

Wobbly

 

[manticle]

Cheers for that wobbly. Cheers also for the earlier suggestion on a hot water run.

 

[MHB]

Just a couple of points that spring to mind
There are kegs other than 5 US Gallon Cornes, there are lots of the old Australian 23L (5 Imp Gal) kegs kicking around, here are a couple on eBay, should make for much better batch sizes.
PRV's cant leak gas in, well unless they are stuffed, they are basically a one way valve with a spring holding them down.
I to would be very concerned about O2 ingress, not just HSA but if you are no-chilling in the keg - plain straight old fashioned oxidisation - the beer wont be better for exposure to oxygen for any length of time.
Both poppets can let air in as vacuum forms, for air to travel in through the liquid the vacuum would have to be the same as the wet height of the dip-tube and the density of the wort according to P=ρgh (ρ being density, g gravity, h height). Just on my fingers about -6 to -7 kPa (about -1 psi for the luddites) so more than doable if the gas poppet was a bit sticky.
I think the perfect solution would be a CO2 and cask aspirator, it just lets in a vacuum relieving amount gas.

I have a friend who was doing this, brewing here in Newcastle, putting the wort into a 45L keg (the old Australian type with a hatch and poppets like a corny), pressurising with CO2 as the wort cooled, then fitting a HEPA filter to the gas post for the drive over the range to Tamworth,
The beer was never as good as that which was taken home in cubes, we put it down to oxidisation from air getting in and out from the altitude change, he has gone back to using cubes.

Mark

 

[manticle]

Thanks Mark.

I would be pitching as soon as the wort is cool. I don't tend to store wort in cubes for much more than one or two days and this would be no different. However one of the main attractions is reducing oxidation so hopefully it doesn't have the opposite effect.

If I block the gas post with the co2 disconnect and the beer with my black disconnect connected to pluto overnight, then pitch the next day would I hopefully be avoiding the issues your friend had?

I hope to give this a go next weekend if I can nut this out correctly

 

[MHB]

I strongly suspect that if you don't do something to relieve the vacuum it will suck air in, if you have everything else blocked then it will suck it in around the hatch O-Ring. Remember kegs are designed to hold pressure not vacuum.
mark

 

[mb-squared]

I read through all the comments on this post and couldn't help but ask why you don't just chill the wort before dumping it into the keg? Is there an advantage (that I'm clearly missing) to not chilling your wort?

 

[TheWiggman]

The yeast/trub could presumably be dealt with with either shortened dip tube (but then I need kegs designated only for that purpose)

If you have a spare dip tube around, why not just shorten it and fit it when needed? Only involves removing the liquid post then re-fitting.

 

[breakbeer]

I read through all the comments on this post and couldn't help but ask why you don't just chill the wort before dumping it into the keg? Is there an advantage (that I'm clearly missing) to not chilling your wort?

Not everyone has a chiller