Undercarbed with Set and Forget Method

[smack2000]

I'm relatively new to kegging, having done about 5 or 6 batches. I'm doing the set and forget method, 12 psi at 40 degrees for a pale ale, which seems right on, according to the carbonation chart. After three weeks, my beer is still significantly undercarbed. After about 6 weeks, the carbonation level is fine. I know I could raise the pressure initially and/or shake the keg periodically, but I'm curious as to why this is happening. The only thing I can figure is there is too little head space (they are pretty full 5 gallon batches) but I don't know to what extent that is a factor.

Any thoughts would be appreciated. Thanks.

 

[Hammy71]

I would suggest that either the accuracy of your thermometer or you regulator may be in question. Three weeks is usually more than enough to properly carb a keg. I'd try to bump the pressure to maybe 15 psi on the next batch and see if that helps. Worth a shot....

 

[Dan]

Just a SWAG, maybe the lack of head space is a factor? One way to rule that out us to pour off a glass or two and then

 

[Dan]

Just a SWAG, maybe the lack of head space is a factor? One way to rule that out us to pour off a glass or two and then

Oops. My phone hiccuped.

Try carbonating. As was already wisely stated, I paraphrase, the equipment you're using might be fau

 

[Dan]

Oops. My phone hiccuped.
D
Try carbonating. As was already wisely stated, I paraphrase, the equipment you're using might be fau

No joy replying on my phone to

 

[hunter_le five]

How are you measuring the temperature of the beer in the keg?

Usually 3 weeks is adequate.

 

[day_trippr]

I agree that 3 weeks at the appropriate pressure for the beer temperature should have fully carbed a five gallon corny of any moderate FG brew (bigger FG brews take longer in my experience). So I'd also check the thermometer and low pressure gauge accuracies in this case, because unless there's a pellicle or an oil slick riding atop that beer there's something else going on.

wrt to head space, with the slightest sliver of the entire diameter of the keg exposed to the incoming gas - ie, the maximum available surface area - the rate of carbonation isn't going to change.. Other than the fact that a half-filled keg will take much less time to achieve full carbonation all other factors equal, an inch deep empty space isn't going to be any more effective than a half inch at infusing the CO2 into the beer...

Cheers!

 

[paperairplane]

Maybe what the carbonation chart says - and what you think is appropriate - are not the same....

I tend to like my beer colder and more carbonated than would be ideal - luckily for me, it's my beer, my recipe and my keezer and I drink it how I likes it.

I usually do a day or two at 20-30 psi then set on service pressure for a week. YMMV

 

[smack2000]

How are you measuring the temperature of the beer in the keg?

Usually 3 weeks is adequate.

It's in a converted chest freezer controlled by a Johnson digital controller. I think the temp is accurate.

 

[smack2000]

I agree that 3 weeks at the appropriate pressure for the beer temperature should have fully carbed a five gallon corny of any moderate FG brew (bigger FG brews take longer in my experience). So I'd also check the thermometer and low pressure gauge accuracies in this case, because unless there's a pellicle or an oil slick riding atop that beer there's something else going on.

wrt to head space, with the slightest sliver of the entire diameter of the keg exposed to the incoming gas - ie, the maximum available surface area - the rate of carbonation isn't going to change.. Other than the fact that a half-filled keg will take much less time to achieve full carbonation all other factors equal, an inch deep empty space isn't going to be any more effective than a half inch at infusing the CO2 into the beer...

Cheers!

Thanks for the explanation of the head space issue.

 

[hunter_le five]

It's in a converted chest freezer controlled by a Johnson digital controller. I think the temp is accurate.

Cool, that's what I use. How do you have the probe set up though?

 

[Bobby_M]

I also like my beers a bit more carbonated than most guidelines. I prefer about 2.8 volumes in pale ales so that's closer to 16 psi at 40F in my case. It's also pretty common for the cheap secondary gauges on regulators to be off by a couple PSI if the scale is 0-60. I replaced a few of them on my secondary bank with 0-15 and it's amazing how little you need to move the regulator to make a change from 14psi to 15. No way to get that accuracy at 0-60.

 

[day_trippr]

Just out of curiosity, when you (the op) draw a pint, do you get a good pour (a finger or two of head) or do you get a half glass of beer with the rest being foam?

This goes to the question of perceived carbonation remaining in the beer after a minute or two, which excessive head will attenuate most assuredly...

Cheers!

 

[smack2000]

Cool, that's what I use. How do you have the probe set up though?

Through the side wall, extended into the interior about 3 inches, sealed with silicone, and the probe not touching anything.

 

[hunter_le five]

Through the side wall, extended into the interior about 3 inches, sealed with silicone, and the probe not touching anything.

I've got my probe taped to one of the kegs underneath some insulation.

Measuring just the air temp inside the chest freezer makes it difficult to get an accurate read on the beer temp, in my experience.


Sent from my iPad using Home Brew

 

[smack2000]

Just out of curiosity, when you (the op) draw a pint, do you get a good pour (a finger or two of head) or do you get a half glass of beer with the rest being foam?

This goes to the question of perceived carbonation remaining in the beer after a minute or two, which excessive head will attenuate most assuredly...

Cheers!

I'm just using a picnic tap at this point, with about 8 feet of line. At a pressure of 12 psi I tend to get excessive foam, yes, often a half glass of foam. So are you saying I may be underestimating the degree of actual carbonation?

 

[smack2000]

I also like my beers a bit more carbonated than most guidelines. I prefer about 2.8 volumes in pale ales so that's closer to 16 psi at 40F in my case. It's also pretty common for the cheap secondary gauges on regulators to be off by a couple PSI if the scale is 0-60. I replaced a few of them on my secondary bank with 0-15 and it's amazing how little you need to move the regulator to make a change from 14psi to 15. No way to get that accuracy at 0-60.

.
I have a taprite regulator, which I bought new, and the scale is 0-60. I will look into a 0-15. Maybe I'll start by pushing it up to 16.

(I got all my fittings, tubing, pump, and sight glasses from you - thanks for your great products and service!)

 

[smack2000]

I've got my probe taped to one of the kegs underneath some insulation.

Measuring just the air temp inside the chest freezer makes it difficult to get an accurate read on the beer temp, in my experience.


Sent from my iPad using Home Brew

Thanks, didn't know this.

 

[day_trippr]

I'm just using a picnic tap at this point, with about 8 feet of line. At a pressure of 12 psi I tend to get excessive foam, yes, often a half glass of foam. So are you saying I may be underestimating the degree of actual carbonation?

Ah hah! Mystery solved!

That excessive foam is using up the CO2 that used to be dissolved in your beer.
Hence, what's left tastes flat.

Solve the foam problem and you'll be in the same carbonation reality with the rest of us

Cheers!

 

[smack2000]

Ah hah! Mystery solved!

That excessive foam is using up the CO2 that used to be dissolved in your beer.
Hence, what's left tastes flat.

Solve the foam problem and you'll be in the same carbonation reality with the rest of us

Cheers!

Nice! That must be it. I will drop down to a better serving pressure and see how it goes.

Thanks and Cheers!

 

[smack2000]

I cut the pressure down to 7-8 psi, and all's right with the world!

Thanks to all who weighed in.

 

[Yooper]

That's not going to work long-term. It will try to equalize and cause some foaming as well as letting the beer go flat. The easy solution is simply to get longer lines. Try 10 to 12 feet of beer line and magically your beer will be perfect.

 

[smack2000]

That's not going to work long-term. It will try to equalize and cause some foaming as well as letting the beer go flat. The easy solution is simply to get longer lines. Try 10 to 12 feet of beer line and magically your beer will be perfect.

Hey, thanks man. I wondered about that.

I don't know about perfect.