Foamy pour with no gas in beer line?

[spacey]

Last week I found my sanke connector had a bad o-ring on the bottom and replaced it with a new D-style connector with keg lube and that fixed the air pockets and spitting coming out of the tap during the pour. Now the pours come out 25%-30% foam instead of 50% foam, The foam comes out at the first second, and seems to clear up completely after one more second.

With my previous homebrews, if there was a foam issue, there were always bubbles and air in the beer line, large and/or small. This time, there are no bubbles or air pockets in the line before or after each pour.

The keg is commercial sanke from a microbrewery, they (the servings girl) told me they use 10 PSI pouring pressure but didn't know the beer line length, I can't get any more info out of them. The volumes of CO2 in their 5 gallon commercial keg is unknown at this point.

Foam comes out the first 1-2 seconds, and then a good clean pour after that. The video kind of shows that, but I couldn't tilt the glass since I was recording, so the foam was even worse. Perlick adjustable faucet seems to make no difference. When the PSI is around 3 PSI, it does pour slower but the foam is still about 20% foam, 80% beer.

Kegerator is 3/16" ID vinyl with 8 feet length, D-style connector to commercial keg with an adapter to quick connects. Kegerator temp is around 38F.

Serving pressure has been changed from 5 PSI to begin, slowly brought it up to 15 PSI. Always foam city 25%-50%.

Should I extend the beer line length to 12' or more and keep the PSI at 10-15 PSI? I have extra new line to use.

My homebrews pour much more slowly even with a Blue Moon clone at 12 PSI serving pressure. Looking at the video, it looks like the beer is coming out too fast, so longer line?

 

[day_trippr]

Have you ever seen a bartender pour beer like that? I know, one handed and all, but it totally obliterates the pour so we can't tell what else might be going on. You are literally air-dropping beer by at least a foot into an empty glass, which immediately causes foam which in turn provides a crapton of nucleation sites for carbonation break-out. Don't do that. Hold the glass right under the spout at an angle, fully open the faucet and allow the beer to "slide" down the glass until you have a few inches of beer in the glass. Then gradually rotate the glass upright until it's filled to your satisfaction.

Also...cold glasses help, and even better, a wetted cold glass will help keep imperfections in a glass from causing rampant nucleation.

Finally, I would change the lines to at least 10 footers and probably 12 feet to slow the pour down...

Cheers!

 

[spacey]

Okay, new video.

Beer lines are now 12 feet long (3/16" inner diameter), no real change. Gas builds up in the lines after a glass is poured and moves upwards slowly in the line. The pour is air, foamy beer, then clear beer at the end.

This is the second 5 gallon commercial keg from the brewery, so I don't think the keg is overcarbonated. It's a sour beer, maybe they carbed it very high?

Since it's not the line length, diameter, temp, there has to be air getting into the line from the connector. It's the second I've tried in two weeks. I hooked up the same black quick connect to a homebrew keg and it poured normal out of the tap, so the problem must be before the black connector.

Keg lube is on the bottom seals of the D-style coupler and top adapter to the quick connects.

I tried 5 PSI, 10 PSI and 15 PSI. 5 is the best of the three since it comes out a little slower but still does the same thing.

 

[spacey]

Bought a third coupler to try on the commercial keg. This one is a low profile D-style coupler with no seals or adapters on the top at all.

There is only one seal that could let air into the line - where the ball on the commercial keg meets the coupler.

The pour is better, but CO2 still degasses in the vinyl line after a pour in the 12' beer line, you get 2 seconds of foam and then a better pour.

With 3/16" inner diameter vinyl beer line, 12 feet long at 8 PSI, a pint pours in about 5 seconds, it should be taking much longer.

My conclusion is that the keg itself has a high volume of CO2, the cheap adapters I bought for $15 leaked easily, this new coupler should have fixed the foaming issue but it only helped somewhat.

The beer in the keg either has to be degassed before it's poured, or the PSI has to be set at 3-5 PSI to slow the pour down enough for a pint to be drinkable.

 

[DuncB]

Can you let us know the temperature of the beer.
The psi that the beer is under. Not i'm lowering pressure to 3 psi . If you leave the keg with no gas on it for a few hours and then put the pressure gauge on it. This will allow an accurate calculation of your beer vols of CO2. What height is the tap above the middle of the keg?
What beer style is it as well?
With that info we can then use a beer line length calculator and see whether a 12 foot line is the right length.

 

[day_trippr]

At this point I expect the CO2 pressure vs temperature combination is insufficient to keep the CO2 that was dissolved in the beer from breaking out. Add more pressure until the keg stops outgassing and see what happens then...

Cheers!

 

[spacey]

You're right - that was the last piece of the puzzle, it pours correctly now!!!

1 - The first coupler was defective

2 - The second copuler had cheap quick connect adapters that were letting air into the beer line during the pour, serving pressure of 5 PSI was the only way to get a glass poured that was drinkable

3 - The serving pressure needed to be 10-12 PSI to prevent degassing in the beer line, after the other issues were fixed

THANKS DAY_TRIPPR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[day_trippr]