Carbonation Issue

[ericbw]

I have the same issue. Beer on the line goes flat. I assume there's a tiny vent somewhere letting gas out.

The "check" idea makes sense.

 

[Thorsbrew]

Well i needed some new ball locks for 2 other kegs anyway. I'll try that the next time i go to my LHBS. Though i doubt it as i've had identical issues on 2 kegs with 2 separate ball lock disconnects.

 

[ericbw]

I think if the ball lock were the problem, it would be causing a problem for the keg. It seems like the line is separated from the keg - so when it loses carb, it makes a big difference. But I also think this is just a small issue for me.

The soda keg, with 25 feet of line, is more bothersome.

 

[MagicMatt]

Hmm well mine is more like 3-4 maybe even 5 ounces before any carbonation shows up.

It's closer to 3 oz (actually less than 3 oz). It's a pretty simple cylindrical volume equation:

V = = πr²h

where
r = line radius = 1.5/16 in = 0.0942 in
h = line length = 15 ft = 180 in

So:
V = π · (0.0942 in)² · 180 in ≈ 5.018 in³

And since 1 in³ = 0.554 fl oz, then 5.018 in³ = 2.78 fl oz. of liquid in your 15ft, 3/16" lines.

FWIW, I too often experience flat beer in the line (my lines are about 8-10', so only 1-2oz), but I just pour it all into my glass and when full, you'd never notice. At least I can never tell the difference. I've even poured 2 pints side by side, the first being a "first pour" where the line is flat, and couldn't tell them apart by sight or taste.

 

[Thorsbrew]

Well i dont know what to tell you.....maybe the beer in the dip tube is going flat too? Either way it definitely seems like more than that to me. I'll measure next time.

 

[Thorsbrew]

Well alright, that's pretty close. Looked like a lot more to me. It took (measured it) about 3 ounces before i started to see very minor bubbles but it wasnt until 4 ounces that there was really any foam.

 

[jan_b19]

I feel like your beer line is way to long. i would go for 4,5-6 feet at 15 psi
I have a calculator for this, but it's in metric units and in dutch... I'll try to make a translated version when i have the time.
so with a temperature of 36°F (2.2°C) and 3 vol. CO2 you need 1,05 bar or 15.2 PSI.
Beer line: I don't have all the information available cause i would need to know the distance between the middle of the keg and the tap (height) for a accurate calculation.
I'm gonna do 2 calculations one with a distance of 1 foot and one with a distance of 2 feet.
both use 3/16 line with a resistance of 3psi/feet.

1 foot: beer line with a length of 4,3 feet
2 feet: beer line with a length of 4,1 feet
You need shorter line to get the beer to the tap if you don't want to increase the pressure.

God i hate converting units.
I really don't understand why you drink your beer so cold tho. 48°F is the ideal beer temperature. But hey if you like it who am i to tell you otherwise

And as a answer to the previous post. He's right the pressure doesn't drop in the line. But that doesn't mean the beer won't go flat. In the keg the beer stays carbonated in the line the beer goes flat because the CO2 escapes from the beer because the beer is heating up once it leaves the keg. With a length of 14 feet that means he has a lot of flat beer in his lines.

 

[day_trippr]

I feel like your beer line is way to long. i would go for 4,5-6 feet at 15 psi[...]
both use 3/16 line with a resistance of 3psi/feet.
[...]

That's a classic recipe for horrible pours.
The only beer line length calculator worth using will tell you why.
http://www.mikesoltys.com/2012/09/17/determining-proper-hose-length-for-your-kegerator/

Cheers!

 

[MagicMatt]

I feel like your beer line is way to long. i would go for 4,5-6 feet at 15 psi

I second day_trippr's comment. Do not listen to this guy. 4 feet at 15 psi will give you nothing but foam, and lots of it.

 

[Thorsbrew]

I feel like your beer line is way to long. i would go for 4,5-6 feet at 15 psi
I have a calculator for this, but it's in metric units and in dutch... I'll try to make a translated version when i have the time.
so with a temperature of 36°F (2.2°C) and 3 vol. CO2 you need 1,05 bar or 15.2 PSI.
Beer line: I don't have all the information available cause i would need to know the distance between the middle of the keg and the tap (height) for a accurate calculation.
I'm gonna do 2 calculations one with a distance of 1 foot and one with a distance of 2 feet.
both use 3/16 line with a resistance of 3psi/feet.

1 foot: beer line with a length of 4,3 feet
2 feet: beer line with a length of 4,1 feet
You need shorter line to get the beer to the tap if you don't want to increase the pressure.

God i hate converting units.
I really don't understand why you drink your beer so cold tho. 48°F is the ideal beer temperature. But hey if you like it who am i to tell you otherwise

And as a answer to the previous post. He's right the pressure doesn't drop in the line. But that doesn't mean the beer won't go flat. In the keg the beer stays carbonated in the line the beer goes flat because the CO2 escapes from the beer because the beer is heating up once it leaves the keg. With a length of 14 feet that means he has a lot of flat beer in his lines.

Yes but, how/where does the carbonation escape? Also the beer cant be heating up because the lines are entirely in the keezer.

As for the length i was thinking about reducing the length despite using this length based on what that site (that others also recommended) told me. I have a neighbor that brews beer as well and he said he uses short line lengths like that and doesnt have an issue (or at least noticeably i assume, as youd have much less lost carbonation in that length).

As for temperature i didnt give it much thought. It was partially so i didnt have to use as much PSI and use an even longer length of line and partially because that just seemed right. I could try a little warmer but i dont want to go up and down on temps for the whole kegs too much. 48 sounds really warm though.

 

[MagicMatt]

FWIW I carb most of my beers to 2.5 vols, which means just over 11psi @ 38°F, and I use 10ft lines without a problem. However, when serving something carbed to 3 vols, I get a bit more foam than I want with the 10ft lines, so I have a 15ft line I use for those beers.

15 ft of line is probably a slight excess for your situation, but I wouldn't go too far down. I think 12ft should work for you provided your taps are at least a foot or two above the kegs. Longer lines will not cause you any problems though, so personally I'd just leave it. That's because line resistance decreases exponentially as flow rate decreases. Whenever I'm calculating line length (using the one linked by day_trippr), I always add a foot to what it tells me just for reassurance.

 

[MagicMatt]

And I just want to reiterate what Juan pointed out:

There's a lot of bad information out there regarding "balancing" draft beer systems. The vast majority of it completely ignores basic laws of fluid mechanics and makes assumptions that often don't apply to homebrewers. The first misconception might stem from the phrase "line balancing". This implies that there's some magic balance between pressure and resistance that results in a good pour, and anything else will cause foam. This couldn't be further from the truth.

The reason resistance is required in a draft system is to slow the flow of beer down until it's gentle enough that the CO2 doesn't get knocked out of solution and result in a ton of foam as it makes it from the faucet to the glass. How slow and gentle the pour needs to be to accomplish this is highly dependent on the serving temperature and carbonation level of the beer. The warmer or more highly carbed the beer is, the slower and gentler the pour needs to be.

For commercial systems where the beer is stored between 33° and 36° and the carbonation level is between 2.5 and 2.7 vol, people have found that the fastest a beer can be poured without excessive foam is ~1 gal/min. All of the equations,resistance figures, calculators, and most of the articles you've likely found assume this flow rate. There are a couple problems with this assumption. First, if you use those equations and resistance figures you'll end up with a flow rate of 1 gal/min, which in many cases is too fast and will result in a fire hose of foam. The second is that line resistance is not a constant for a given type of beer line, it's dependent on the flow rate. This means that those figures and equations are completely useless for any flow rate other than 1 gal/min.

The other common misconception is that extra long lines, or additional resistance beyond the "ideal" or "balanced" figures will cause some sort of problems or foaming. There are only two side effects of extra long lines, a very slightly slower pour, and the ability to serve beer at a much wider variety of temperatures and carb levels without any issues. Since line resistance decreases exponentially as flowrate decreases, doubling your beer line length barely has a noticeable impact on how long it takes to fill a pint.

 

[doug293cz]

Yes but, how/where does the carbonation escape? Also the beer cant be heating up because the lines are entirely in the keezer.

As for the length i was thinking about reducing the length despite using this length based on what that site (that others also recommended) told me. I have a neighbor that brews beer as well and he said he uses short line lengths like that and doesnt have an issue (or at least noticeably i assume, as youd have much less lost carbonation in that length).

As for temperature i didnt give it much thought. It was partially so i didnt have to use as much PSI and use an even longer length of line and partially because that just seemed right. I could try a little warmer but i dont want to go up and down on temps for the whole kegs too much. 48 sounds really warm though.

You are correct, no CO2 escapes from the lines when the tap is closed. There is also no pressure drop along the line when beer is not flowing. The pressure drops from keg to tap when the beer flows during the pour... it is a dynamic effect, not static.

Since you don't lose carbonation when the taps are closed, and the lines are the same temp as the keg, there is no line length to carbonation loss correlation. Use the longer lines to prevent potential foaming problems that can be caused by fast pours (what you get with shorter lines, due to less line resistance.)

Don't listen to what anyone else tells you about beer serving temp. Whatever you prefer is the correct temp, for you. Same with carbonation levels. You do need to set your line lengths based on actual pressure (as determined by temperature and carb level.)

Brew on

 

[jan_b19]

Yes but, how/where does the carbonation escape? Also the beer cant be heating up because the lines are entirely in the keezer.

As for the length i was thinking about reducing the length despite using this length based on what that site (that others also recommended) told me. I have a neighbor that brews beer as well and he said he uses short line lengths like that and doesnt have an issue (or at least noticeably i assume, as youd have much less lost carbonation in that length).

As for temperature i didnt give it much thought. It was partially so i didnt have to use as much PSI and use an even longer length of line and partially because that just seemed right. I could try a little warmer but i dont want to go up and down on temps for the whole kegs too much. 48 sounds really warm though.

Well the carbonation doesnt really have to escape, the beer in the line will lose it's carbonation and the CO2 will go up to the top of the line (near your tap) where it might gather.

When you open your tap does any air come out or does the beer flow instantly?

 

[jan_b19]

I second day_trippr's comment. Do not listen to this guy. 4 feet at 15 psi will give you nothing but foam, and lots of it.

Well clearly we have other experiences. I never had to much foam, but i do like a nice 1,5 inch head on my beers tho

 

[Thorsbrew]

Well the carbonation doesnt really have to escape, the beer in the line will lose it's carbonation and the CO2 will go up to the top of the line (near your tap) where it might gather.

When you open your tap does any air come out or does the beer flow instantly?

Flows instantly.

 

[jan_b19]

That's a classic recipe for horrible pours.
The only beer line length calculator worth using will tell you why.
http://www.mikesoltys.com/2012/09/17/determining-proper-hose-length-for-your-kegerator/

Cheers!

that would be true if you would follow the 10 seconds/pint flow rate setting. However if we change the flow rate to a more realistic number (between 5,5-8s/pint) you'll see that the calculator will recommend a way shorter beer line: Between 4,8 feet at 5,5 seconds/pint and 9,3 feet at 8 seconds/pint.
So those 4-5-6 feet lines i suggested actually seem to be bang on.

Now, we can keep arguing about these numbers but we won't know for sure until we know the actual flow rate. Cause flow rate changes everything.