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Date: 18 Aug 2006 09:33:02
From: Don Levey
Subject: Carbonation pressure v Dispensing
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Here's the second kegging question from last night's insomnia:
At 72F, I need about 22 PSI on my keg to impart the desired degree
of carbonation to my beer. But based upon the size/length of my tap
line (see? Sometimes size DOES matter), I will be dispensing at
12 PSI.
This leeds me to believe that I'll either end up dispensing at too
high a pressure, decarbonating my beer, or taking other measures,
which might include:
* dropping the temp of the keg during tapping to make the carbonation
and dispensing pressure equalise.
* lengthen my tap line to take up the additional pressure.
* relieve pressure when I pour, and repressurize when I'm done
What do others do?
--
Don Levey $ cd /pub
Framingham, MA $ more beer
NOTE: email server uses spam filters; mail sent to salearn@the-leveys.us
will be used to tune the blocking lists.
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Date: 18 Aug 2006 13:15:48
From: Jim
Subject: Re: Carbonation pressure v Dispensing
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Don Levey wrote on 8/18/2006 9:33 AM:
> Here's the second kegging question from last night's insomnia:
>
> At 72F, I need about 22 PSI on my keg to impart the desired degree
> of carbonation to my beer. But based upon the size/length of my tap
> line (see? Sometimes size DOES matter), I will be dispensing at
> 12 PSI.
>
> This leeds me to believe that I'll either end up dispensing at too
> high a pressure, decarbonating my beer, or taking other measures,
> which might include:
>
> * dropping the temp of the keg during tapping to make the carbonation
> and dispensing pressure equalise.
>
> * lengthen my tap line to take up the additional pressure.
>
> * relieve pressure when I pour, and repressurize when I'm done
>
> What do others do?
>
I just tapped my first keg this week. Perfect timing for this post.
This really is an art. One thing that surprised me is that carbonation
really impacts the taste of the beer. I was disappointed yesterday but
now that the carb level is more normal, the beer tastes better.
Jim
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Date: 18 Aug 2006 17:30:06
From: Thomas T. Veldhouse
Subject: Re: Carbonation pressure v Dispensing
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Jim <Jim@no.com > wrote:
> I just tapped my first keg this week. Perfect timing for this post.
>
> This really is an art. One thing that surprised me is that carbonation
> really impacts the taste of the beer. I was disappointed yesterday but
> now that the carb level is more normal, the beer tastes better.
>
Indeed ... the less carbonated a beer is, the sweeter the apparent aroma.
--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1
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Date: 18 Aug 2006 17:03:19
From: Tom Veldhouse
Subject: Re: Carbonation pressure v Dispensing
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Don Levey <Don_RCB@the-leveys.us > wrote:
> Here's the second kegging question from last night's insomnia:
>
> At 72F, I need about 22 PSI on my keg to impart the desired degree
> of carbonation to my beer. But based upon the size/length of my tap
> line (see? Sometimes size DOES matter), I will be dispensing at
> 12 PSI.
>
> This leeds me to believe that I'll either end up dispensing at too
> high a pressure, decarbonating my beer, or taking other measures,
> which might include:
>
> * dropping the temp of the keg during tapping to make the carbonation
> and dispensing pressure equalise.
>
> * lengthen my tap line to take up the additional pressure.
>
> * relieve pressure when I pour, and repressurize when I'm done
>
> What do others do?
>
Lower the temp and leave it that way [I use a chest freezer with a controller
to maintain the desired temperature]. Set the pressure to the carbonation
level you want your beer at. Make your liquid line as long as is required to
balance the system [at 22 PSI in your case, that is a long line ... about 11
feet or so]. My system sits at about 40F, 11 PSI and the liquid line is a bit
over 5 feet.
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Date: 18 Aug 2006 14:36:36
From: John 'Shaggy' Kolesar
Subject: Re: Carbonation pressure v Dispensing
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On 18 Aug 2006 09:33:02 -0400, <Don_RCB@the-leveys.us > wrote:
> Here's the second kegging question from last night's insomnia:
>
> At 72F, I need about 22 PSI on my keg to impart the desired degree
> of carbonation to my beer. But based upon the size/length of my tap
> line (see? Sometimes size DOES matter), I will be dispensing at
> 12 PSI.
IMO, always make your dispensing pressure and carbonation pressure the
same.
You said you're carbonating at 72F... are you also going to serve the
beer at 72F? If yes, then you will want to serve using 22 PSI and you'll
have to adjust the length of your tap lines to balance this. If you're
going to drop the temp of the keg before you serve it, then figure out
what the carbonation pressure at the lower temp will be, and make that
your dispensing pressure.
Here's basically how you design a balanced kegging system. First, start
by deciding what temp you want your beer and how much carbonation you
would like. Those two decisions set up everything else. Then, look up
on a chart what CO2 PSI is required to hit the desired temp and level of
carbonation that you picked. Make your dispensing PSI be the same as your
carbonation PSI. Then, based on that PSI, you figure out how much tubing
you need.
> * dropping the temp of the keg during tapping to make the carbonation
> and dispensing pressure equalise.
You don't *have* to drop the temp, but you do need to take it into
account. IE, decide what temp you'll be serving at first.
> * lengthen my tap line to take up the additional pressure.
Yes, you want to make sure that your dispensing and carbonation pressure
are the same, and then adjust the line to match. You don't really do
it the other way around... IE start with a fixed line and adjust your
temp/pressure to match the line. That's kind of backwards. Don't let
a piece of tubing dictate what your beer is going to taste like. Figure
that out first, and then make the tubing match it.
> * relieve pressure when I pour, and repressurize when I'm done
This will probably be a big pain, and likely cause inconsistent carbonation
levels. I wouldn't do this.
John.
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Date: 18 Aug 2006 12:05:07
From: Don Levey
Subject: Re: Carbonation pressure v Dispensing
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John 'Shaggy' Kolesar <spam@shagg.net > writes:
> On 18 Aug 2006 09:33:02 -0400, <Don_RCB@the-leveys.us> wrote:
> > Here's the second kegging question from last night's insomnia:
> >
> > At 72F, I need about 22 PSI on my keg to impart the desired degree
> > of carbonation to my beer. But based upon the size/length of my tap
> > line (see? Sometimes size DOES matter), I will be dispensing at
> > 12 PSI.
>
> IMO, always make your dispensing pressure and carbonation pressure the
> same.
>
> You said you're carbonating at 72F... are you also going to serve the
> beer at 72F? If yes, then you will want to serve using 22 PSI and you'll
> have to adjust the length of your tap lines to balance this. If you're
> going to drop the temp of the keg before you serve it, then figure out
> what the carbonation pressure at the lower temp will be, and make that
> your dispensing pressure.
>
THat was what occurred to me this morning at the gym. I had
forgotten to take Boyle's Law into account. Bringing that same
beer down to 52F brings the pressure down to 12.2 PSI - which is
right around the dispensing pressure (and not an unreasonable
temp at which to serve).
>
> > * lengthen my tap line to take up the additional pressure.
>
> Yes, you want to make sure that your dispensing and carbonation pressure
> are the same, and then adjust the line to match. You don't really do
> it the other way around... IE start with a fixed line and adjust your
> temp/pressure to match the line. That's kind of backwards. Don't let
> a piece of tubing dictate what your beer is going to taste like. Figure
> that out first, and then make the tubing match it.
>
I guess I should keep a number of different tap lines on hand.
> > * relieve pressure when I pour, and repressurize when I'm done
>
> This will probably be a big pain, and likely cause inconsistent carbonation
> levels. I wouldn't do this.
>
Yeah, and apparently not necessary. Thanks, all!
--
Don Levey $ cd /pub
Framingham, MA $ more beer
NOTE: email server uses spam filters; mail sent to salearn@the-leveys.us
will be used to tune the blocking lists.
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Date: 18 Aug 2006 18:41:49
From: Scott Sellers
Subject: Re: Carbonation pressure v Dispensing
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Don Levey <Don_RCB@the-leveys.us >:
>John 'Shaggy' Kolesar <spam@shagg.net> writes:
>> On 18 Aug 2006 09:33:02 -0400, <Don_RCB@the-leveys.us> wrote:
>> > Here's the second kegging question from last night's insomnia:
>> >
>> > At 72F, I need about 22 PSI on my keg to impart the desired degree
>> > of carbonation to my beer. But based upon the size/length of my tap
>> > line (see? Sometimes size DOES matter), I will be dispensing at
>> > 12 PSI.
>>
>> IMO, always make your dispensing pressure and carbonation pressure the
>> same.
>>
>> You said you're carbonating at 72F... are you also going to
>> serve the beer at 72F? If yes, then you will want to serve
>> using 22 PSI and you'll have to adjust the length of your tap
>> lines to balance this. If you're going to drop the temp of
>> the keg before you serve it, then figure out what the
>> carbonation pressure at the lower temp will be, and make that
>> your dispensing pressure.
>>
>THat was what occurred to me this morning at the gym. I had
>forgotten to take Boyle's Law into account. Bringing that same
>beer down to 52F brings the pressure down to 12.2 PSI - which is
>right around the dispensing pressure (and not an unreasonable
>temp at which to serve).
To me it seems easiest to think of carbonation level in terms of
"volumes of CO2". Decide on that, then relate temperature and
pressure accordingly. With 22lbs. CO2 applied at 72F, you'll
reach equilibrium at 1.76 volumes of CO2. The same volumes CO2
can then be maintained, for example, with 8lbs. pressure at 50F,
or with 5lbs. pressure if at 42F.
Serving hose length is then determined by the pressure required
to maintain the chosen volumes CO2 at the chosen serving temp.
Scott S
--
Scott Sellers
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Date: 18 Aug 2006 15:25:08
From: Don Levey
Subject: Re: Carbonation pressure v Dispensing
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Scott Sellers <scottsellers@mindspring.com > writes:
>
> To me it seems easiest to think of carbonation level in terms of
> "volumes of CO2". Decide on that, then relate temperature and
> pressure accordingly. With 22lbs. CO2 applied at 72F, you'll
> reach equilibrium at 1.76 volumes of CO2. The same volumes CO2
> can then be maintained, for example, with 8lbs. pressure at 50F,
> or with 5lbs. pressure if at 42F.
>
> Serving hose length is then determined by the pressure required
> to maintain the chosen volumes CO2 at the chosen serving temp.
>
Interesting - the calculator at hbd.org gives 2 volumes at 72F
for 21.8 PSI.
--
Don Levey $ cd /pub
Framingham, MA $ more beer
NOTE: email server uses spam filters; mail sent to salearn@the-leveys.us
will be used to tune the blocking lists.
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Date: 18 Aug 2006 22:06:01
From: Scott Sellers
Subject: Re: Carbonation pressure v Dispensing
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Don Levey <Don_RCB@the-leveys.us >:
>Scott Sellers <scottsellers@mindspring.com> writes:
>>
>> To me it seems easiest to think of carbonation level in terms of
>> "volumes of CO2". Decide on that, then relate temperature and
>> pressure accordingly. With 22lbs. CO2 applied at 72F, you'll
>> reach equilibrium at 1.76 volumes of CO2. The same volumes CO2
>> can then be maintained, for example, with 8lbs. pressure at 50F,
>> or with 5lbs. pressure if at 42F.
>>
>> Serving hose length is then determined by the pressure required
>> to maintain the chosen volumes CO2 at the chosen serving temp.
>>
>Interesting - the calculator at hbd.org gives 2 volumes at 72F
>for 21.8 PSI.
I was going by a chart that I googled up at:
http://sdcollins.home.mindspring.com/ForceCarbonation.html
It was hard to find one that went up to 70F. I extrapolated from
there to 72F. (Some only go up to 40F! I guess they never heard
of ale.)
I can't vouch for accuracy vs. your source. However, the numbers
from the lower temps (50F and 42F) match the ones from the chart
I have at hand.
cheers,
Scott S
--
Scott Sellers
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Date: 19 Aug 2006 13:14:56
From: Wheat
Subject: Re: Carbonation pressure v Dispensing
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Here's a link previously posted by Alf McLaughin to: "The Beer Recipator" -
Copyright 1997-1998 Mark Riley .
http://hbd.org/cgi-bin/recipator/recipator/carbonation.html?7812606#tag
Basically a beer carbonation calculator.
Bill
"Scott Sellers" <scottsellers@mindspring.com > wrote in message
news:dRqFg.5520$Sn3.1707@newsread3.news.pas.earthlink.net...
> Don Levey <Don_RCB@the-leveys.us>:
>
>>Scott Sellers <scottsellers@mindspring.com> writes:
>
>>>
>>> To me it seems easiest to think of carbonation level in terms of
>>> "volumes of CO2". Decide on that, then relate temperature and
>>> pressure accordingly. With 22lbs. CO2 applied at 72F, you'll
>>> reach equilibrium at 1.76 volumes of CO2. The same volumes CO2
>>> can then be maintained, for example, with 8lbs. pressure at 50F,
>>> or with 5lbs. pressure if at 42F.
>>>
>>> Serving hose length is then determined by the pressure required
>>> to maintain the chosen volumes CO2 at the chosen serving temp.
>>>
>>Interesting - the calculator at hbd.org gives 2 volumes at 72F
>>for 21.8 PSI.
>
> I was going by a chart that I googled up at:
>
> http://sdcollins.home.mindspring.com/ForceCarbonation.html
>
> It was hard to find one that went up to 70F. I extrapolated from
> there to 72F. (Some only go up to 40F! I guess they never heard
> of ale.)
>
> I can't vouch for accuracy vs. your source. However, the numbers
> from the lower temps (50F and 42F) match the ones from the chart
> I have at hand.
>
> cheers,
> Scott S
>
> --
> Scott Sellers
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Date: 18 Aug 2006 17:36:17
From: John 'Shaggy' Kolesar
Subject: Re: Carbonation pressure v Dispensing
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On 18 Aug 2006 12:05:07 -0400, <Don_RCB@the-leveys.us > wrote:
>> Yes, you want to make sure that your dispensing and carbonation pressure
>> are the same, and then adjust the line to match. You don't really do
>> it the other way around... IE start with a fixed line and adjust your
>> temp/pressure to match the line. That's kind of backwards. Don't let
>> a piece of tubing dictate what your beer is going to taste like. Figure
>> that out first, and then make the tubing match it.
>>
> I guess I should keep a number of different tap lines on hand.
If you want to have very different levels of carbonation for your beers,
then it'd probably be a good idea. However, the balancing thing is more a
rule of thumb than an actual law. "Close enough" definitely applies. If
you only want to make minor changes to carbonation levels, you probably
don't need to have seperate sets of tubing. The best thing is to experiment
and see. If you start getting a lot of foam when you pour, that tells you
that your line isn't the right length.
John.
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Date: 18 Aug 2006 09:17:45
From: Mark R
Subject: Re: Carbonation pressure v Dispensing
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"Don Levey" <Don_RCB@the-leveys.us > wrote in message
news:m34pwa9njl.fsf@dauphin.the-leveys.us...
> Here's the second kegging question from last night's insomnia:
>
> At 72F, I need about 22 PSI on my keg to impart the desired degree
> of carbonation to my beer. But based upon the size/length of my tap
> line (see? Sometimes size DOES matter), I will be dispensing at
> 12 PSI.
>
>
> What do others do?
Your ahead of the curve if you've already figured out that you'll have those
problems. Do a google search to check the RCB archives and you'll find tons
of info on "balancing" your kegging system. The short version----
1. Carbonate your brew at serving temp when possible.
2. 3/16 serving hose has about 2 psi of pressure resistance per foot of
hose.
3. Balanced system has serving hose long enough to equal a pressure drop
from serving pressure to 0 psi at the tap. The perfect pour
4. Most use around 12 psi to maintain the desired carbonation, thus 12 psi
serving pressure. About 6 feet of hose should balance the system. Start
long, cut excess.
5. Serving pressure can very some what depending on serving temp and brew
style.
try this link for some more info
http://kegman.net/balance.html
Mark R
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Date: 18 Aug 2006 08:51:36
From: Larry Bristol
Subject: Re: Carbonation pressure v Dispensing
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Don Levey wrote:
> What do others do?
I put beer into the cooler as soon as it is kegged, and do the conditioning
at serving temperature and pressure. I also established the length of the
tap lines so that they are balanced for the same pressure. As a result,
it's pretty much keg it, wait 7-10 days for it to carbonate, then enjoy! I
haven't changed the setting on my regulator for years!
--
Larry Bristol --- The Double Luck
http://www.doubleluck.com
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