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Half Filling Kegs?

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BPH87

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Is it ok to half fill a 19lt keg?

Cheers
 

BPH87

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Cheers for the speedy replies!
 

brettprevans

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Do u care how much u fill up a bottle? A keg is a big arse stainless bottle. Carb and ur away.
 

adraine

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Would that mean your using more gas? Or the same as the gas is in solution if the keg is full?
 

Nick JD

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They force carb way easier too if you don't fill them to the top. I usually put around 14-17L in kegs.
 

Nick JD

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In particular with the 'Ross' method - more head space = less rocking.

:icon_cheers:
I roll them on the ground. You get a massive surface area that way. Getting gas to dissolve is all about area.
 

Cocko

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I roll them on the ground. You get a massive surface area that way. Getting gas to dissolve is all about area.
Tru dat! Tho..

I no longer rock or roll, it is just overnight styles for me these days...

:icon_cheers:


HA - 'Rock or Roll' .... funny....
 

brettprevans

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Would that mean your using more gas? Or the same as the gas is in solution if the keg is full?
What do u think? more vacant volume will be filled by gas. So yes initially. Obviously as any keg drains u get more more dead space filled by gas but in this case u start with more deadspace
 

QldKev

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would it be half full or half empty
 

adraine

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What do u think? more vacant volume will be filled by gas. So yes initially. Obviously as any keg drains u get more more dead space filled by gas but in this case u start with more deadspace
I understand that logic I'm not a complete fool. I however was asking about the amount of gas in solution rather than in the dead space. Do you know the ratio of gas in solution in a std draught beer for example vs the dead space i.e. 60% - 100%? So as to see the amount of gas wasted or to look at the workflow and see if there is a way to recover it.
 

pk.sax

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It's called equal pressure. The pressure of the gas in solution and that of gas in the space above will be the same, occupy ye same volume etc. so, whatever pressure you've dialled in, the amount of gas from the cylinder that is required to carbonate the beer to that will be the same as what is in the headspace if you half fill the keg.

PS: that is what an ideal gas (something like helium) will behave like. CO2 is not ideal but it's still a good approximation.

In other words, if you are carbonating to 3 volumes of CO2, you need 3 volumes to dispense as well or 6 volumes for the whole keg. Volumes of full keg, of course. Start at half a keg and you are carbonating to 1.5 vol CO2, fillin the dead space with another 1.5 vol and going to need another 1.5 vol to empty the keg. That is 4.5 vol for half keg of beer vs 6 vol for full keg, obviously, it is wasteful.
 

QldKev

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I understand that logic I'm not a complete fool. I however was asking about the amount of gas in solution rather than in the dead space. Do you know the ratio of gas in solution in a std draught beer for example vs the dead space i.e. 60% - 100%? So as to see the amount of gas wasted or to look at the workflow and see if there is a way to recover it.

I say no, it would not require more CO2. Beer has approx 2.5x (ie 250%) CO2 in solution. But the key here is you may be starting with 50% full of CO2, but with either a full or half keg of beer, when empty you still end up with a full keg of CO2. So a full keg would need a full keg worth of CO2 to dispense. A half keg will need half a keg up front to fill the empty space, but only draw another half a keg worth to dispense.

But to put your mind further at ease, even if you wasted half a keg vol of CO2, it would not cost that much. We know we use 2.5x to carb and 1x to dispense = 3.5x volume. Depending on where you get your CO2 from, it cost me $1.50 to carb and dispense a keg. So if I wasted say 1/2 a keg vol it works out to be 1/7 of $1.50 = 22c.

QldKev
 

QldKev

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hocus pocus?
2.5x is a lot better number than 3x for most standard beer styles.

edit: updated to include carb levels of beers

American Amber Ale: 2.2-2.8
American Brown: 1.5-2.5
American Dark Lager: 2.5-2.7
American Lager: 2.6-2.7
American Light Lager: 2.6
American Pale Ale: 2.2-2.8
American Pilsener: 2.6-2.7
American Premium Lager: 2.6-2.7
American Wheat: 2.3-2.6

Bamberg Rauchbier: 2.2-2.6
Barley Wine: 1.3-2.3
Belgian Dubbel: 1.9-2.4
Belgian Fruit Lambic: 2.6-4.5
Belgian Gueuze Lambic: 3.0-4.5

Belgian Lambic: 3.0-4.5
Belgian Pale Ale: 1.9-2.5
Belgian Strong Ale: 1.9-2.4
Belgian Tripel: 1.9-2.4
Belgian White (Wit): 2.1-2.6
Berliner Weisse: 3.5
Bire de Garde:
Bock: 2.2-2.7
Bohemian Pilsener: 2.3-2.5
Brown Porter: 1.7-2.5

California Common: 2.4-2.8
Cream Ale: 2.6-2.7

Doppelbock: 2.3-2.6
Dortmunder/European Export: 2.6
Dunkelweizen: 3.6-4.5
Dsseldorf Altbier: 2.2-3.1

Eisbock: 2.4

English Best (Special) Bitter: 0.75-1.3
English Brown: 1.5-2.3
English Dark Mild: 1.3-2.0
English Light Mild: 1.3-2.0
English Old/Strong Ale: 1.5-2.3
English Ordinary Bitter: 0.75-1.3
English Pale Ale: 1.5-2.3
English Strong (Extra Special) Bitter: 0.75-1.3

Flanders Brown: 1.9-2.5
Foreign-Style Stout: 2.3-2.6

German Pilsener: 2.5

Helles Bock: 2.2-2.7

Imperial Stout: 1.5-2.3
India Pale Ale: 1.5-2.3
Irish Dry Stout: 1.6-2.0

Klsch: 2.4-2.7

Maibock: 2.2-2.7

Mrzen/Oktoberfest: 2.6-2.7
Mnchner Helles: 2.3-2.7
Munich Dunkel: 2.2-2.7

North German Altbier: 2.2-3.1

Oatmeal Stout:
Oud Bruin: 1.9-2.5

Robust Porter: 1.8-2.5

Schwarzbier: 2.2-2.6
Scottish Export Ale: 0.75-1.3
Scottish Heavy Ale: 0.75-1.3
Scottish Light Ale: 0.75-1.3
Strong Scotch Ale: 1.5-2.3
Sweet Stout: 2.0-2.4

Traditional Bock: 2.2-2.7

Vienna: 2.4-2.6

Weizen/Weissbier: 3.6-4.5
Weizenbock: 3.7-4.7
 

pk.sax

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Hey Kevin, I was referring to the 'need 1x vol to dispense part'. I can't make head or tail of that.

I just used 3 vol as a simple number to illustrate the calculation, 2.5 is likely more appropriate, I don't measure any longer, if it feels right then it does :)
 

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