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Date: 10 Jul 2006 20:48:13
From: Alf McLaughlin
Subject: Artifically Carbonating a Keg at Room Temperature
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Hello all-
I have artifically carbonated all of my corny kegs to date, but so
far I have been doing it in the keg fridge. I have the need to brew a
large (~6 5-gallon cornies) quantity of beer for a party and will not
have the fridge space available to artifically carbonate at ~38F. I
understand that Co2 absorbs more easily into beer at colder
temperatures, but suppose I hook a corny up to the Co2 and leave it at
10-12 PSI at room temperature. How long will it take to carbonate vs.
~38F? My experience is that this takes about 7-10 days at 10-12 PSI.
My guess is that given all the time in the world, there will be no
difference between the level of carbonation at 38F vs. 70F, but I am
hoping it will not take too long at 70F (but I do have about 2 months
to complete this and 1 of the 6 beers is almost ready to be kegged).
Thanks,
Alf
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Date: 10 Jul 2006 21:34:02
From: Bob
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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"Alf McLaughlin" <ohmygog@hotmail.com > wrote in message
news:1152589693.225728.86110@m73g2000cwd.googlegroups.com...
> Hello all-
> I have artifically carbonated all of my corny kegs to date, but so
> far I have been doing it in the keg fridge. I have the need to brew a
> large (~6 5-gallon cornies) quantity of beer for a party and will not
> have the fridge space available to artifically carbonate at ~38F. I
> understand that Co2 absorbs more easily into beer at colder
> temperatures, but suppose I hook a corny up to the Co2 and leave it at
> 10-12 PSI at room temperature. How long will it take to carbonate vs.
> ~38F? My experience is that this takes about 7-10 days at 10-12 PSI.
> My guess is that given all the time in the world, there will be no
> difference between the level of carbonation at 38F vs. 70F, but I am
> hoping it will not take too long at 70F (but I do have about 2 months
> to complete this and 1 of the 6 beers is almost ready to be kegged).
>
If it is going to be served cold, you would probably want to use higher
pressure at high temp to get the same amount of CO2 into the beer
after it is cooled.
If you want to speed up the process, you can increase the pressure
significantly for shorter periods of time. Removing the CO2 pressure
and shaking the corny vigorously will put the extra CO2 into solution.
You can then check the pressure to see how far along it is in the process.
Bob
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Date: 11 Jul 2006 08:10:34
From: Scott L
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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Alf McLaughlin wrote:
> Cool! It makes sense that there is a way to calculate this. I'll
> check out the evaluation version of ProMash; looks like for my
> situation to carbonate at room temperature without agitation I can
> expect to apply about 3X more pressure to the keg.
There's a free online pressure calculator at:
http://hbd.org/cgi-bin/recipator/recipator/carbonation.html
Another way to figure out the pressure you need for a given
carbonation, is to get a beer which HAS that level of carbonation and
then change the temperature to your given temperature. The pressure in
the headspace of the keg will now be equal to the required pressure.
The pressure you need to carbonate beer to a given level is basically
how much the gas "pushes back" in an effort to get out of the beer. You
have to push at the same level in order to maintain the carbonation.
Of course, there's the (big) issue of achieving equilibrium, which
basically means that beer cannot gain/lose carbonation instantly. When
you crank your regulator to 25 PSI at room temp, the beer is not
suddenly carbonated, rather it dissolves into the beer at a rate
dictated by the current carbonation and the head space pressure -- the
CO2 regulator maintains that constant head pressure, but there is a
flow of gas as the beer carbonates.
Scott
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Date: 11 Jul 2006 07:52:42
From: brian@yahoo.com
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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John 'Shaggy' Kolesar wrote:
> On Tue, 11 Jul 2006 07:29:37 -0700, <bobnospam@gmail.com> wrote:
> >
> > "John 'Shaggy' Kolesar" <spam@shagg.net> wrote in message
> >> The only tricky part is going to be carbonating at one temp, and then
> >> changing the temp in order to dispense the keg. You might run into a
> >> situation where the headspace of the keg will need to be bled once the
> >> keg is chilled down. You'll have to experiment with that.
> >
> > Why would that be? Just because you didn't get the pressure right, or
> > is something else going on?
>
> If you carbonate at 70F at 27 PSI, you'll end up with carbonated beer and
> have 27 PSI in the headspace. If you then chill the keg down to 38F,
> you're still going to have 27 PSI in the headspace (at least for awhile).
> You probably don't want to serve the keg with 27 PSI of pressure in it, at
> 38F you'll want to be serving at around 10 PSI. If you don't bleed the
> pressure from the headspace after chilling, the first group of glasses you
> pour are probably going to come shooting out of the tap and cause a lot of
> foaming.
>
>
> John.
Your best bet is to carbonate at 27 PSI and then disconnect the gas
line when you chill the beer. as the temp decreases, the pressure of
the head space should drop to about 10 PSI due to the temperature
change. Once the beer is fully chilled then re-attach the gas line,
but adjust the regulator down to 10 PSI first. This will prevent any
beer from backing up into the gas line or regulator from low pressure
and also prevent over-carbonating from high pressure.
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Date: 11 Jul 2006 15:01:59
From: John 'Shaggy' Kolesar
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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On 11 Jul 2006 07:52:42 -0700, <brian.sico@gmail.com > wrote:
> Your best bet is to carbonate at 27 PSI and then disconnect the gas
> line when you chill the beer. as the temp decreases, the pressure of
> the head space should drop to about 10 PSI due to the temperature
> change. Once the beer is fully chilled then re-attach the gas line,
> but adjust the regulator down to 10 PSI first. This will prevent any
> beer from backing up into the gas line or regulator from low pressure
> and also prevent over-carbonating from high pressure.
That'll work as long as there is enough time between when you chill and
when you serve. The 27PSI will equalize with the beer as the temp lowers,
but it is not instantaneous. IOW, if you pull a warm keg out of the closet
and stick in your freezer for serving, it's probably going to take longer
for the pressure to normalize than it does for the beer to reach your
target temp. So if you start serving as soon as the beer is cold you'll
likely have problems with the beer coming out of the tap way too fast. If
you chill all of the kegs ahead of time for the party (like a day or two in
advance), then you shouldn't have any problems.
If it is a problem, all you need to do is release the pressure from the keg
first, and then hook it back up to your regulator set at 10PSI (or whatever
your serving pressure will be). I just mentioned it so that the original
poster would be aware of the potential problem, and know what to do
in case they ran into it.
John.
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Date: 11 Jul 2006 13:33:04
From: John 'Shaggy' Kolesar
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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On 10 Jul 2006 20:48:13 -0700, <ohmygog@hotmail.com > wrote:
> Hello all-
> I have artifically carbonated all of my corny kegs to date, but so
> far I have been doing it in the keg fridge. I have the need to brew a
> large (~6 5-gallon cornies) quantity of beer for a party and will not
> have the fridge space available to artifically carbonate at ~38F. I
> understand that Co2 absorbs more easily into beer at colder
> temperatures, but suppose I hook a corny up to the Co2 and leave it at
> 10-12 PSI at room temperature. How long will it take to carbonate vs.
> ~38F? My experience is that this takes about 7-10 days at 10-12 PSI.
> My guess is that given all the time in the world, there will be no
> difference between the level of carbonation at 38F vs. 70F, but I am
> hoping it will not take too long at 70F (but I do have about 2 months
> to complete this and 1 of the 6 beers is almost ready to be kegged).
The pressure for a certain level of carbonation will change depending
on the temp. It should take approximately the same amount of time at 70F,
but you'll have to use a higher pressure in order to hit the same level.
There are lots of charts available on the web that will give you PSI vs temp.
Try googling for "carbonation chart" or something like that. You should
get lots of hits. I've seen a couple charts that only cover the colder
range and stop before they get up to room temp, but if you look at a few
of them you should find what you need. I don't have any links on hand, but
I've definitely seen them before.
The only tricky part is going to be carbonating at one temp, and then
changing the temp in order to dispense the keg. You might run into a
situation where the headspace of the keg will need to be bled once the
keg is chilled down. You'll have to experiment with that.
John.
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Date: 11 Jul 2006 07:29:37
From: Bob
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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"John 'Shaggy' Kolesar" <spam@shagg.net > wrote in message
> The only tricky part is going to be carbonating at one temp, and then
> changing the temp in order to dispense the keg. You might run into a
> situation where the headspace of the keg will need to be bled once the
> keg is chilled down. You'll have to experiment with that.
Why would that be? Just because you didn't get the pressure right, or
is something else going on?
Bob
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Date: 11 Jul 2006 14:36:48
From: John 'Shaggy' Kolesar
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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On Tue, 11 Jul 2006 07:29:37 -0700, <bobnospam@gmail.com > wrote:
>
> "John 'Shaggy' Kolesar" <spam@shagg.net> wrote in message
>> The only tricky part is going to be carbonating at one temp, and then
>> changing the temp in order to dispense the keg. You might run into a
>> situation where the headspace of the keg will need to be bled once the
>> keg is chilled down. You'll have to experiment with that.
>
> Why would that be? Just because you didn't get the pressure right, or
> is something else going on?
If you carbonate at 70F at 27 PSI, you'll end up with carbonated beer and
have 27 PSI in the headspace. If you then chill the keg down to 38F,
you're still going to have 27 PSI in the headspace (at least for awhile).
You probably don't want to serve the keg with 27 PSI of pressure in it, at
38F you'll want to be serving at around 10 PSI. If you don't bleed the
pressure from the headspace after chilling, the first group of glasses you
pour are probably going to come shooting out of the tap and cause a lot of
foaming.
John.
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Date: 11 Jul 2006 06:28:13
From: Alf McLaughlin
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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> If the temperature is 38F, it calculates you need 9.15 PSI.
> At 72F, it calculates 26.72 PSI.
>
> As you can see, you can readily calculate the amount of CO2 pressure needed
> to achieve a given level of carbonation under varying conditions. It's a
> handy little tool!
>
> --
> Larry Bristol --- The Double Luck
Cool! It makes sense that there is a way to calculate this. I'll
check out the evaluation version of ProMash; looks like for my
situation to carbonate at room temperature without agitation I can
expect to apply about 3X more pressure to the keg.
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Date: 11 Jul 2006 13:58:07
From: John 'Shaggy' Kolesar
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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On 11 Jul 2006 06:28:13 -0700, <ohmygog@hotmail.com > wrote:
>> If the temperature is 38F, it calculates you need 9.15 PSI.
>> At 72F, it calculates 26.72 PSI.
>>
>> As you can see, you can readily calculate the amount of CO2 pressure needed
>> to achieve a given level of carbonation under varying conditions. It's a
>> handy little tool!
>>
>> --
>> Larry Bristol --- The Double Luck
>
> Cool! It makes sense that there is a way to calculate this. I'll
> check out the evaluation version of ProMash; looks like for my
> situation to carbonate at room temperature without agitation I can
> expect to apply about 3X more pressure to the keg.
I found one of the charts I mentioned in my other post:
http://hbd.org/ford/brewinfo/kegcarb.html
This is all ProMash is doing. IE, you type in the information and they're
just doing a lookup internally on the same sort of chart.
John.
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Date: 11 Jul 2006 04:34:19
From: Alf McLaughlin
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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> If it is going to be served cold, you would probably want to use higher
> pressure at high temp to get the same amount of CO2 into the beer
> after it is cooled.
Thanks for replying, Bob. The plan is indeed to serve it cold. I'm
reluctant to use the shaking method and I'd rather let it carbonate
without being agitated (I have force carbonated before with success,
but it strikes me as a bit hit or miss). I wonder what PSI I should
set the CO2 at if I wanted it to carbonate at room temperature without
agitation. Maybe 20 PSI for 7-10 days would have the same effect at
70F as 12 PSI for 7-10 days would at 38F? I can imagine some rule of
thumb like that, but do not want to risk overcarbonating these batches
or else I would just try it myself first.
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Date: 11 Jul 2006 07:36:30
From: Larry Bristol
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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Alf McLaughlin wrote:
> Thanks for replying, Bob. The plan is indeed to serve it cold. I'm
> reluctant to use the shaking method and I'd rather let it carbonate
> without being agitated (I have force carbonated before with success,
> but it strikes me as a bit hit or miss). I wonder what PSI I should
> set the CO2 at if I wanted it to carbonate at room temperature without
> agitation. Maybe 20 PSI for 7-10 days would have the same effect at
> 70F as 12 PSI for 7-10 days would at 38F? I can imagine some rule of
> thumb like that, but do not want to risk overcarbonating these batches
> or else I would just try it myself first.
If you have access to ProMash, its "bottling and kegging" panel will do the
calculation for you. You set the desired carbonation level, the size of
the keg, the number of days you will let it sit, and the temperature.
Press the "Calc" button, and it tells you the CO2 pressure you need to
achieve that carbonation level.
For example:
Desired carbonation Average (2.30 CO2 Vol)
Gallons 5.0
Days Conditioned 7
If the temperature is 38F, it calculates you need 9.15 PSI.
At 72F, it calculates 26.72 PSI.
As you can see, you can readily calculate the amount of CO2 pressure needed
to achieve a given level of carbonation under varying conditions. It's a
handy little tool!
--
Larry Bristol --- The Double Luck
http://www.doubleluck.com
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Date: 11 Jul 2006 11:59:03
From: Alf McLaughlin
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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> If you carbonate at 70F at 27 PSI, you'll end up with carbonated beer and
> have 27 PSI in the headspace. If you then chill the keg down to 38F,
> you're still going to have 27 PSI in the headspace (at least for awhile).
> You probably don't want to serve the keg with 27 PSI of pressure in it, at
> 38F you'll want to be serving at around 10 PSI. If you don't bleed the
> pressure from the headspace after chilling, the first group of glasses you
> pour are probably going to come shooting out of the tap and cause a lot of
> foaming.
I suppose another potential concern is that a perfectly carbonated keg
at room temperature with 27 PSI head space will absorb the unwanted CO2
in the headspace one it is chilled (given enough time). Bleeding the
pressure makes sense.
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Date: 11 Jul 2006 19:10:02
From: John 'Shaggy' Kolesar
Subject: Re: Artifically Carbonating a Keg at Room Temperature
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On 11 Jul 2006 11:59:03 -0700, <ohmygog@hotmail.com > wrote:
>> If you carbonate at 70F at 27 PSI, you'll end up with carbonated beer and
>> have 27 PSI in the headspace. If you then chill the keg down to 38F,
>> you're still going to have 27 PSI in the headspace (at least for awhile).
>> You probably don't want to serve the keg with 27 PSI of pressure in it, at
>> 38F you'll want to be serving at around 10 PSI. If you don't bleed the
>> pressure from the headspace after chilling, the first group of glasses you
>> pour are probably going to come shooting out of the tap and cause a lot of
>> foaming.
>
> I suppose another potential concern is that a perfectly carbonated keg
> at room temperature with 27 PSI head space will absorb the unwanted CO2
> in the headspace one it is chilled (given enough time). Bleeding the
> pressure makes sense.
True, but the headspace usually holds a pretty minimal volume of gas. As long
as the keg was full, even though the extra 27PSI worth of gas will disolve
into the beer, I don't think that we're talking enough volume wise to make
a really big difference. You're correct though, technically that will
raise your carbonation level some. IMO, the larger issue is just the force
from that higher pressure during serving.
John.
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