Tap Pouring Foam

[Wduncan1983]

I recently made a vodka seltzer for a Christmas party and forced carbonated at 30PSI for the first two days. I dropped it to 12 PSI and it poured okay during the party. Although, a week later it's pouring and I'm having breakout where the seltzer is flat. I'm using 3/16 ID soft tubing with about 17 feet of line. When pouring, I can see in the line that it's foaming in the line before it even hits the tap. I've tried to increase the carbonation levels but anything over 20 just foams and has the same result. Any idea's?

 

[wepeeler]

I recently made a vodka seltzer for a Christmas party and forced carbonated at 30PSI for the first two days. I dropped it to 12 PSI and it poured okay during the party. Although, a week later it's pouring and I'm having breakout where the seltzer is flat. I'm using 3/16 ID soft tubing with about 17 feet of line. When pouring, I can see in the line that it's foaming in the line before it even hits the tap. I've tried to increase the carbonation levels but anything over 20 just foams and has the same result. Any idea's?

First off, your line is WAY too long for 12psi. 10ft of 3/16 ID should be plenty long for pouring Seltzer at 12psi. That being said, 12psi is way too low for seltzer. I usually carb it to 35-40psi, then dispense around 15-20psi. 10ft of tubing should still be plenty long. Your first pour might be a lot of foam, but after the line cools, it should pour better.

 

[Wduncan1983]

10-4... thank you for the updates. I'll shorten the line tonight. I only carbed to 30PSI so I'll need to increase that as well. I'm also thinking of buying a perlick flow control tap to help as well.

 

[day_trippr]

fwiw, shortening the line is definitely NOT what needs to be done at all. Indeed, you probably don't have enough line.
What temperature this seltzer is going to be maintained at will help determine what should be done.

[edit] In the meantime, here's an example of a properly configured dispensing system, assuming seltzer held at 40°F and carbonated to 4 volumes of CO2 (which is fairly typical I believe).

First, referencing our favorite carbonation table, find 40°F on the Y-Axis, and scan across that row to the closest entry to 4 volumes, then run up that column to find the required CO2 pressure to maintain the seltzer at 4 volumes of CO2 at 40°F. Which happens to be 29 psi.

Then, referencing the only line length calculator worth using, plug in the 29 psi for the CO2 pressure, keep the default line ID of 0.1875", change the vertical distance from the middle of your keg to the faucet spout if the default 1.5 feet isn't close, change the flow rate if you must (I'd keep the 10 second pint myself), change the default FG to 1.000 or something close for the seltzer, and leave the tubing "roughness" number alone.

The magic number required is calculated to be almost 26' of 3/16" ID solid vinyl tubing (ala Bevlex 200, which has been pretty much the industry standard beverage tubing for decades). But if one wanted to cut down the line requirement, consider using 4mm ID EVABarrier tubing - or even their 3mm ID line...

Cheers!

 

[wepeeler]

fwiw, shortening the line is definitely NOT what needs to be done at all. Indeed, you probably don't have enough line.
What temperature this seltzer is going to be maintained at will help determine what should be done.

[edit] In the meantime, here's an example of a properly configured dispensing system, assuming seltzer held at 40°F and carbonated to 4 volumes of CO2 (which is fairly typical I believe).

First, referencing our favorite carbonation table, find 40°F on the Y-Axis, and scan across that row to the closest entry to 4 volumes, then run up that column to find the required CO2 pressure to maintain the seltzer at 4 volumes of CO2 at 40°F. Which happens to be 29 psi.

Then, referencing the only line length calculator worth using, plug in the 29 psi for the CO2 pressure, keep the default line ID of 0.1875", change the vertical distance from the middle of your keg to the faucet spout if the default 1.5 feet isn't close, change the flow rate if you must (I'd keep the 10 second pint myself), change the default FG to 1.000 or something close for the seltzer, and leave the tubing "roughness" number alone.

The magic number required is calculated to be almost 26' of 3/16" ID solid vinyl tubing (ala Bevlex 200, which has been pretty much the industry standard beverage tubing for decades). But if one wanted to cut down the line requirement, consider using 4mm ID EVABarrier tubing - or even their 3mm ID line...

Cheers!

I pour Seltzer carbed to 35-40 psi with 7ft of 3/16" ID tubing with no issues.

 

[Bobby_M]

The problem is that the seltzer was carbed to 30psi and you are trying to pour it at 1/3rd of that. As soon as you open the tap, there's a pressure drop and CO2 cracks out of solution. The stable way to pour out of kegs is to pour at the same pressure the beverage is carbonated to. I carb/pour my seltzer at 25psi and I have 8ft of 4mm ID tubing, which is about the equivalent of 12ft of 3/16".

 

[day_trippr]

I pour Seltzer carbed to 35-40 psi with 7ft of 3/16" ID tubing with no issues.

There's always someone who claims miraculously excellent results in spite of some crazy math

Cheers!

 

[wepeeler]

There's always someone who claims miraculously excellent results in spite of some crazy math

Cheers!

I pour my seltzer with my quoted specs routinely. Just trying to help the OP, not get into a pissing contest. 26' of tubing is wildly unnecessary.

 

[DuncB]

This line calculator copes with metric and imperial also a mix of units. Based off soltys work.
https://brewingcalculators.com/beer-line-length/It also includes Final gravity factor which might be a confounder in the soda and alcoholic seltzer situation.

 

[Wduncan1983]

I set the temp to 40 degrees and carbed it to 40psi. This is what I'm getting no matter the psi I set it to pour.

 

[Bobby_M]

40psi is too high regardless, back down to 25-30psi and vent the keg. It does look like you're getting some CO2 bypassing into the liquid flow though. The most common reason is a questionable oring on the liquid diptube (you have to wrench off the male QD post to get to it). The lesser reason, though I've seen it twice now, is a pinhole leak in the diptube.

You can rule out or confirm the CO2 bypass theory by laying the keg on its side with the liquid port down. If the foaming and sputtering stops, that WAS/IS the problem. If it keeps going it on the side, then it's just over carbonated.

 

[DuncB]

@Bobby_M
Great tip about diagnosing the Oring problem by laying keg on its side.

 

[Wduncan1983]

40psi is too high regardless, back down to 25-30psi and vent the keg. It does look like you're getting some CO2 bypassing into the liquid flow though. The most common reason is a questionable oring on the liquid diptube (you have to wrench off the male QD post to get to it). The lesser reason, though I've seen it twice now, is a pinhole leak in the diptube.

You can rule out or confirm the CO2 bypass theory by laying the keg on its side with the liquid port down. If the foaming and sputtering stops, that WAS/IS the problem. If it keeps going it on the side, then it's just over carbonated.

Replaced the oring and the dip tube and problem was solved. The old dip tube had worn a hole about a 1/3 away from the top which is why it started after the first 15-20 pours. Appreciate the suggestion!

 

[Bobby_M]

I'm glad you followed up. If I were to scour the forum, I'd probably find the ten times over the years that I mentioned the possibility of a pinhole in the diptube and someone always chimes in that it's so unlikely that there's no way...

 

[day_trippr]

Still rare though: there have been a total of three confirmed cases of holed beer dip tubes in my time on HBT..

Cheers!

 

[DuncB]

Still rare though: there have been a total of three confirmed cases of holed beer dip tubes in my time on HBT..

Cheers!

Thanks Statto!

 

[passedpawn]

I'm glad you followed up. If I were to scour the forum, I'd probably find the ten times over the years that I mentioned the possibility of a pinhole in the diptube and someone always chimes in that it's so unlikely that there's no way...

I had this exact problem a year ago. Dented flare at the top of the dip tube allowed gas to flow around the oring and directly into the beer line. Looked exactly like an overcarbed beer. I replaced the dip tube and beer flowed perfectly.

 

[passedpawn]

Still rare though: there have been a total of three confirmed cases of holed beer dip tubes in my time on HBT..

Cheers!

LOL!

 

[pvpeacock]

One of my 2 soda water kegs started sputtering recently. I was convinced it was the o-ring on the post. It wasn't. I was then convinced it was the Kegland flow control disconnect. It wasn't. Then I found this thread and changed out the dip tube and its o-ring. Voila! While I couldn't identify a pinhole in the diptube itself, I did note a slight bend in the flange of the diptube which was likely the cause. Thank you everyone for solving my problem before I even had it!

 

[Broken Crow]

I had this exact problem a year ago. Dented flare at the top of the dip tube allowed gas to flow around the oring and directly into the beer line. Looked exactly like an overcarbed beer. I replaced the dip tube and beer flowed perfectly.

View attachment 837678

Before my injury, I spent most of my life repairing all manner of wierd damage and usually been able to figure out how it occurred so that I can ensure it doesn't happen again or that I don't do it myself.....Looking at the picture I cannot for the life of me figure out how that could have happened.
Do you know how it happened or have any theories?

 

[passedpawn]

Before my injury, I spent most of my life repairing all manner of wierd damage and usually been able to figure out how it occurred so that I can ensure it doesn't happen again or that I don't do it myself.....Looking at the picture I cannot for the life of me figure out how that could have happened.
Do you know how it happened or have any theories?

No idea. It's possible I got the keg that way and never noticed (and it never leaked). Also possible I damaged it, though I can't imagine how (looks like it fell into the garbage disposal). It's gonna remain a mystery, unfortunately.

Far more likely to have a missing or broken oring.

 

[day_trippr]

I have a long dip tube with a tiny pie slice shape missing from the flange. It was a well used keg when I got it, and fortunately that missing bit has never affected the integrity of the keg (I'd be looking for CO2 sneaking from the headspace into the beer stream). I have other dip tubes that had dents and ripples in their flanges when I got them. Flattened them out by dropping them down into a bench vise and doing some cautious tapping on the flanges.

I expect the damage was mostly due to misaligned poppets when the posts were installed and then tightened down...

Cheers!

 

[pvpeacock]

The good news is that since I have replaced all of my beer keg metal dip tubes (18 kegs in all) with floating dip tubes, I have lots of spare metal dip tubes for my 2 dedicated soda water kegs!