Low carbonation in solution in keg

[bluemoose]

I have always had pretty good carbonation in the kegs. The last five have poured with a good head, but very little co2 in solution. They taste flat. Not sure what to do. I have cleaned the entire beverage line system and taps.
Plenty of co2 in the tank.
Correct pressure
Kegs have been on co2 for weeks

What am I missing? I will definitely take a lot of care when I keg the next beer to make sure the keg parts are all super clean.

 

[KofC]

How new are your o-rings? Have you sprayed some star-san or soapy water around all of the connections and the keg lid to make sure that you don't have any leaks? I've heard that even a tiny leak can keep a keg from carbing up. Also, is the beer coming out the right temperature? Temp has a huge effect on the amount of CO2 that will go into solution at a given pressure.

Good luck!

 

[day_trippr]

Low pressure gauge not reading correctly, perhaps?
Did the tank fall over back when this all started?

A leak that's so small as to not affect the low pressure gauge is unlikely to affect carbonation...

Cheers!

 

[bluemoose]

Plenty of co2 in the kegs. No leaks there. Temp is not an issue either. Sitting at 45 degrees. Double checked with a thermometer.

 

[bluemoose]

The tank has not been damaged. When I express co2 from the keg, I can hear co2 going back in. It has a nice frothy head, great lacing in the glass. Just not much in solution.
I'm thinking there may be something taking it out of solution during the pour?

 

[day_trippr]

Take an honest picture of a typical pour.

My benchmark is 12 ounces of beer poured (metered, so it's not guesswork) with a scant two finger head, in a 16 ounce Sam Adams glass.
If there's more head, there's less residual carbonation. Those bubbles have to come from somewhere and in this case it is indeed a zero sum game.

Is this happening on more than one keg?

Cheers!

 

[bluemoose]

Happening on two out of 4 kegs. The other two are higher gravity. They seem to be pretty good.

 

[bluemoose]

Will take a picture of the next beer.

 

[Bobby_M]

How long is your serving line?

 

[bluemoose]

View attachment ImageUploadedByHome Brew1424042585.615000.jpgjust poured.

 

[day_trippr]

Looks like a perfect pour from here
I don't think your dispensing system is the issue.

Did the two cranky brews use new-to-you recipes or techniques?
Also, no chance you lost track and the two kegs have only been on gas for a week or so?

Cheers!

 

[bluemoose]

4 ft of bev line.

 

[bluemoose]

No, been on for a while. Just not as carbed as I would like. I wonder if there is something taking the co2 out of solution on pouring. Creating a good head, but flat mouth feel. I'm nervous about kegging the beer that just finished fermenting. I'm thinking about bottling it, just to have the right carb level.

 

[Bobby_M]

That's why I asked. It does look like you're knocking a bit more out of solution than you'd like. Double your serving line length and set the kegger at 40F.

 

[bluemoose]

I used the beer smith formula to determine the line length.

Length=(psi-1)/resistance.

Wouldn't doubling the length increase the resistance too much? I would think that would take more out of solution.

 

[day_trippr]

Beersmith simply copied the same algorithm that 98% of the purported line length calculators are based upon. And BS gets the answer just as wrong.

The only beer line length calculator worth using will provide a proper solution - and an education...

Cheers!

 

[bluemoose]

So no difference between vinyl and PVC?

 

[day_trippr]

I'd say, no. Barrier-lined is another story - the Bev Seal Ultra 235 stuff needs a lot more length than any calculator comes up with. I used to think it was because it isn't a true 3/16" ID but there's conflicting information on that...

Cheers!