Dialing In Keg Carbonation

[brettrae]

Hey all. I'm new to kegging, but was hoping to get some insight into why my beer isn't pouring as foam-free as I would like. Here's some background for reference:

I have a 5 gal keg in a home-made keezer. Initially, I had a really short liquid tube length, a temperature setting that was too high, and inexperience that led me to keep my CO2 on around 25 psi for a week or so. I did this because, even though my beer was coming out all foam, it was also extremely flat when I tasted it. I failed to realize that it was flat because all of the CO2 was being forced out as foam (I think).

Anyways, I did some research (with help from Mike Solty's tube length calculator) and fixed a few things: I extended my liquid lines to 10 1/2 feet, lowered my beer serving temp to 40 degrees, and tried to balance my system to around 14 psi for the saison I made, which I want to be decently carbonated. I've managed to get my initial out of control foam problem under wraps, but I still get about 1/2 pint full of foam to beer ratio when I pour. If I wait it out, I can eventually get a decent pour, but I would love the perfect pour! I am still serving at 14 psi, because that it was the calculator said would fit my line length, etc. for a higher-carbonated beer. Do I need to lower it down to 10 or 12 while serving? And then raise it back up after I do so? Or perhaps my beer is still over-carbonated from my initial mistakes? I'll admit, I still haven't fully grasped the concept of the effects thatbleeding air from the keg and re-setting my CO2 regulator, etc. have on my beer's carbonation. I just don't know why my pour isn't perfect...maybe I'm expecting too much? Any advice would be great! Thank you!!

 

[Yooper]

You don't want to turn down the pressure to serve and then turn it back up, at least not long term, because it will make the foaming issues worse when the pressures attempt to equalize.

I like that calculator better than all the others, but.............my own experience is that I need at least 1 foot of 3/16" like for every psi on the regulator at fridge temps to get a great pour. I have 12 ' lines on my 11 psi regulator right now, and I get a great pour usually. At times, when it's really hot and humid, I'll get a bit of foam (since the faucets are warm), but overall it's really great.

I think, even with the calculator, that your lines are still a bit short, especially for higher carbed beers. You can easily pour a lower carbed beer, I'd bet.

 

[ericbw]

How long ago did you leave it on 25? It takes time to get back down. You have to release the pressure several times a day.

I don't know what the calculator says, but I think 40 degrees + 14psi needs more than 10.5 feet.

Again, it will take time for the excess gas to leave the beer. Vent the keg twice a day at least.

 

[Sailingeric]

You will get foam if your taps are warm. I get some foam on my first pour but if I am pouring several glasses then once the tap gets cool that cuts the foam down to what you would see in a bar.

 

[day_trippr]

Beer held at 40°F and 14 psi of CO2 will eventually hit ~2.7 volumes.
Plugging 14 psi into Mike's calculator with the default 10 second pint results in almost 12 feet of line - not 10.5.

fwiw, Mike doesn't recommend any CO2 pressure. His calculator takes the pressure you define along with a couple of user and beer specific factors and pops out a balanced line length for that specific set of inputs (assuming solid PVC tubing in all cases - PET barrier tubing needs at least another 50% of the recommended length).

1 foot of 3/16" PVC line per CO2 PSI is a quite reasonable rule of thumb. While it will provide a somewhat slower pour and perhaps minimal head during comfortable days it also provides a bit more margin for hot days when breakout wants to happen...

Cheers!

 

[BeardedBrews]

I fought a foamy first pour problem until I realized that the tubing from the keg to the faucet was not at the same temperature as the beer in the bottom of the keg (where the dip-tube picks up). I installed a fan inside the kegerator which fixed the problem basically overnight.

Keep in mind how the elements work together:

1. Temperature - Lower temperature = higher carbonation if the pressure is the same.
2. Pressure - Higher pressure = higher carbonation if the temperature is the same.
2a. Pressure - Higher pressure = faster pour speeds (see #4).
3. Line Length - Longer line = slower pour if the pressure is the same. (A 'flow control' faucet can accomplish the same thing)
4. Beer Agitation - Pouring fast or through disruptive fittings will knock carbonation out of the beer which can cause foaming.

People refer to "balancing" the system because you need to get all of these more or less balanced to each other. Nice slow to moderate speed pour to shake out the amount of head you want, enough pressure and cold enough to keep the carbonation level where you want it.

 

[brettrae]

I finally realized that I should turn it down from 25 PSI about 11 days ago, but I haven't been releasing the pressure from the keg. Should I turn off the switch from the regulator to the keg when I release the pressure in the keg, or does it matter? Also, should I just open the relief valve until no more air is coming out? Thanks!

 

[brettrae]

You will get foam if your taps are warm. I get some foam on my first pour but if I am pouring several glasses then once the tap gets cool that cuts the foam down to what you would see in a bar.

I've heard this before....I wonder if applying some ice to the tap would alleviate this problem some. Not sure if it'd be worth it not to get foam in the first pour or not. Maybe I'll try that.

 

[Sailingeric]

I pour about 1/3 to half glass, stop, let the cooler beer cool the tap and let the foam die down, then pour the rest a couple minutes later.. like a Guinness should be poured.

 

[Yooper]

I finally realized that I should turn it down from 25 PSI about 11 days ago, but I haven't been releasing the pressure from the keg. Should I turn off the switch from the regulator to the keg when I release the pressure in the keg, or does it matter? Also, should I just open the relief valve until no more air is coming out? Thanks!

It's probably overcarbed, but should eventually even out since you're pouring from the keg.

 

[hendenburg2]

One of the things you might want to also look at is the way it comes out when you open the tap. Mine has the problem where there is a "burb" - literally, a bubble forms in the line wherever there is a local high point (ie, the line is traveling upward and then turns around and goes downward), and when that bubble hits the tap, it "burbs" and the flow is interrupted, which causes a lot of gas to come out of solution, which leads to a lot of head. My solution that works really well is to close the tap right after the "burp", let everything settle down for a second or two, and then start pouring again. The technique cuts the amount of head down by 2/3. Of course, this was on a sankey tap and I just discovered that the internal ball was missing, so we'll have to see if replacing it changing it fixes the bubble formation problem, but we'll see.

 

[BeardedBrews]

I finally realized that I should turn it down from 25 PSI about 11 days ago, but I haven't been releasing the pressure from the keg. Should I turn off the switch from the regulator to the keg when I release the pressure in the keg, or does it matter? Also, should I just open the relief valve until no more air is coming out? Thanks!

Releasing the pressure will help, but there is a great Sticky thread on this topic:
https://www.homebrewtalk.com/showthread.php?t=127655

 

[william_shakes_beer]

I finally realized that I should turn it down from 25 PSI about 11 days ago, but I haven't been releasing the pressure from the keg. Should I turn off the switch from the regulator to the keg when I release the pressure in the keg, or does it matter? Also, should I just open the relief valve until no more air is coming out? Thanks!

I usually just pour myself a beer or two each evening. Vents the pressure beautifully. :rockin:

Like others here, I initially struggled with the line length issues and foaming. Then I read one of Yooper's posts, re-centered myself and did the following:

1. Set regulator to 12 PSI and leave it alone
2. 12 feet of 3/16" beer lines
3. Flow control faucets for fine tuning beers that may need more or less pressure (FYI, most of my beers pour fine with flow control "off", IE wide open)
4. set keezer temp controller to 33F and leave it alone
5. locate Keezer temp sensor as close to the bottom of the keezer as possible to eliminate the possibility of icing the keg
6. And here's the most important item: have space in the keezer for one keg more than serving. I always have 2 kegs serving and 1 carbing. I don't consume nearly as much beer as I produce, (that's my drinking problem don't you know) so I can afford to leave a keg carbing for a month or more. I purchased 1 dual pressure regulator so I *could* burst carb if I have a sudden emergency need to carb a keg in a weekend, but thus far that need has not arisen.

 

[owmatooth]

I still don't quite understand if the question is about a problem that occurs during every beer or just the first beer. It seemed like OP said he eventually gets a good pour. Over carbed beer would be consistant across every pour, a change from first beer to third would be a cooling problem in the faucet.

If that's the case you need more cold airflow (usually via small fan) close to your taps, if it's consistent after several beers in succession, it's a co2 problem and just shut the co2 off till the keg co2 drops to acceptable pours then put it back on at 10-12 or whatever you prefer. (with 10.5 ft lines i'd aim for somewhere between 10 and 11 psi

 

[ericbw]

I still don't quite understand if the question is about a problem that occurs during every beer or just the first beer. It seemed like OP said he eventually gets a good pour. Over carbed beer would be consistant across every pour, a change from first beer to third would be a cooling problem in the faucet.

If that's the case you need more cold airflow (usually via small fan) close to your taps, if it's consistent after several beers in succession, it's a co2 problem and just shut the co2 off till the keg co2 drops to acceptable pours then put it back on at 10-12 or whatever you prefer. (with 10.5 ft lines i'd aim for somewhere between 10 and 11 psi

That's good troubleshooting! It is unclear what he means by "if I wait it out."

The one thing about your suggestion is that I don't think 10-11 psi will get him the carbonation level he wants for his beer.

 

[owmatooth]

That's good troubleshooting! It is unclear what he means by "if I wait it out."

The one thing about your suggestion is that I don't think 10-11 psi will get him the carbonation level he wants for his beer.

the three variables in carbonation/foaming involve psi, line length, and temperature. if we're gonna be sticking with 10.5 ft lines, then psi at 10-11 will work given the temperature is set to get the desired dissolved co2. warmer (40 degrees) will give less carbonation and colder (34 F) will give more carbonation. and still have foaming controlled by the line length as a given. how i got away with a 5 ft hose in my original danby kegerator ten years ago I'll never know. Oh wait, i didn't get away with it, I had tons of foam. derp.

its just a balancing act. just trying to remember not to overthink it.

 

[brettrae]

Thank you all for your replies! Eventually, after dialing my PSI down to 12 and waiting for a few days, along with burping the keg, I was able to get a lot less foam out of it. There was still some, but I was able to put up with it. I kicked it yesterday, and will try to carb my keg slowly over a few weeks on the next batch, along with having a longer line to exactly match the beer style. Thanks for all of your advice on this, I really appreciate it! Cheers.

 

[Shwagger]

Heh, I have about 24 inches of line in my mini fridge kegerator. I get foam the first few glasses and then only slightly there afterwards. If it sits a few days with no use I might get a little foam. But a good tilt of the glass and a slow pour results in just the right amount of foam. I use less than ten psi usually. I wing it like most things and profit in the end.

KISS

 

[day_trippr]

[...]I get foam the first few glasses[...]

Unacceptable.

Cheers!

 

[Shwagger]

It turns to beer with time

 

[eric19312]

I used to get foamy pours but that issue went away when I added a computer fan inside the keezer to keep air moving.