Question on Carbing/Serving PSI

[devildancer]

I kegged a Hefe last week, and according to Brewpal the pressure should be set to 30 psi for carbonating. I have done that, now should it be held there for serving too? I have gone through probably a dozen kegs and still haven't nailed down the carb/foaming issues. I'm using 10 or 12' line. FWIW, I just poured one a week old and it came out nicely but not fully carbonated. Thanks, I hope I made sense.

 

[Yooper]

I kegged a Hefe last week, and according to Brewpal the pressure should be set to 30 psi for carbonating. I have done that, now should it be held there for serving too? I have gone through probably a dozen kegs and still haven't nailed down the carb/foaming issues. I'm using 10 or 12' line. FWIW, I just poured one a week old and it came out nicely but not fully carbonated. Thanks, I hope I made sense.

Wow- 30 psi is WAY high. I don't know what "brewpal" is, but it seems to me that if your fridge is in the range of 40 degrees, 12-13 psi is much more reasonable. If you want a high carbonation for a hefe, you could could up to 15-16 psi for approximately 3 volumes of co2.

Here's a carbonation chart: http://www.ebrew.com/primarynews/ct_carbonation_chart.htm

 

[SumnerH]

I kegged a Hefe last week, and according to Brewpal the pressure should be set to 30 psi for carbonating. I have done that, now should it be held there for serving too? I have gone through probably a dozen kegs and still haven't nailed down the carb/foaming issues. I'm using 10 or 12' line. FWIW, I just poured one a week old and it came out nicely but not fully carbonated. Thanks, I hope I made sense.

A week at 30 PSI should be way overcarbonated, assuming that it's at fridge temps during carbonation. But if you're pushing with 30 PSI, too, you're knocking all the CO2 out of solution and generating tons of foam at serving time.

10' of line (assuming it's regular 3/16" bev line) should be plenty for a hefe, and follow the cart Yooper posted to find the right PSI to use.

You should basically be able to put a keg in the fridge, hook up to the gas for a week at 12ish PSI (for average beers) or 15-16 (for hefes and other high-carb beers), and then serve without touching the PSI with no foaming problems. Stouts/british pales/etc may only need 8 PSI or so.

 

[devildancer]

I thought that may be an easy question. I guess I used the temperature of the beer when I kegged it~ 60 degrees or so. Thanks!

 

[SumnerH]

Yeah, that can be confusing, especially when you're first moving from bottling because it's different:
When you're priming for bottles, you're adding a fixed amount of CO2 to what's already in there, so you have to use the highest temperature the beer reached before bottling.

When you're connecting a keg to a CO2 tank, though, you're establishing an equilibrium point independent of what was already in solution, so you need to use the kegerator'd temperature of the beer.

 

[usdsk8er540]

ok. so sorry to dig up an old thread, but here it goes. i just kegged a hefe myself and i have it set at around 15 psi in my mini-fridge kegerator in the garage. the temperature is showing about 32-33 degrees, so i figured it would make it a high carbonation hefe, given the slight fluctuation of temperatures in my garage here in late fall/early winter in missouri. i pulled a half pint off yesterday to see how it was doing (i kegged on wednesday) and it seemed like it just wanted to shoot out way too fast. i am using a picnic tap and have about 4 foot of serving line. i can get more serving line if needed, but i was just curious if it is possible to work with a shorter line and turn down the serving pressure while tapping after the keg is carbonated? or would this knock co2 out of solution or reduce the amount of carbonation? thanks yall.

 

[BigJerk]

I'm curious about this too, I've resigned myself to the fact that I need to get longer serving lines to solve my foaming. Right now I'm carbing up then lowering the serving pressure, but I'm tired of constantly fiddling with the pressures. how long do my lines need to be for 12 psi?

 

[Walker]

There are one or more sticky threads at the top of the bottling/kegging forum that go into great detail about how to balance your draft system properly.

tap line diameter and vertical height from keg to tap all factor into it, but a general rule of thumb is that you want about 1 foot of tap line for every psi of pressure you are serving the beer with.

So... 12psi wants 12 feet of beer line.

 

[IffyG]

but i was just curious if it is possible to work with a shorter line and turn down the serving pressure while tapping after the keg is carbonated? or would this knock co2 out of solution or reduce the amount of carbonation? thanks yall.

You can do that no problem. Drop the pressure at the regulator and purge the keg using the relief valve up top. I did this for a few weeks after I got my first keg, but it got old in a hurry. As soon as I could make a run to the LHBS, I did and got 10 foot lines. Keep in mind when you do this you have to turn the pressure back up when you are done to make sure it doesn't decarbonate (it is in equilibrium after all).

 

[Walker]

i was just curious if it is possible to work with a shorter line and turn down the serving pressure while tapping after the keg is carbonated? or would this knock co2 out of solution or reduce the amount of carbonation? thanks yall.

Depending on what level of carbonation you want and the temp you will be serving at, a certain amount of pressure is required to maintain that level of carbonation.

If you drop the pressure down to serve on the short line and leave it that way, the beer will start to lose carbonation.

 

[AJ_in_HD]

I've had lots of foaming issues running with 5 foot lines. I have the tower cooled as best as I can to 45-50F and at 10 psi the first pint always foams. Every subsequent one would be fine if poured immediately after. Then one day I just decided to lower serving pressure to like 4 psi and my foaming issues went away. Since I just did this I'm not sure about the practicality of losing CO2 over time versus the theoretical fact that I'd expect a drop in CO2 over time. 5 gallon kegs don't really last that long so i am hoping it isn't an issue.

 

[Yooper]

I've had lots of foaming issues running with 5 foot lines. I have the tower cooled as best as I can to 45-50F and at 10 psi the first pint always foams. Every subsequent one would be fine if poured immediately after. Then one day I just decided to lower serving pressure to like 4 psi and my foaming issues went away. Since I just did this I'm not sure about the practicality of losing CO2 over time versus the theoretical fact that I'd expect a drop in CO2 over time. 5 gallon kegs don't really last that long so i am hoping it isn't an issue.

If the kegs lasts a week or two, you'll notice the carb level dropping over time. The only way to prevent it would be to turn the regulator back up to the correct psi after serving, and then reset it lower when you want to serve. That's why most of us just get longer lines- the carbonation, storing, and serving pressure is the same. A balanced system may be as simple as getting longer lines for most of us.

 

[brittney81895]

Ok, I guess this is a pretty dumb question, but how do you read this chart? http://www.kegerators.com/carbonation-table.php I have a porter on tap and it seemed to go flat after a few hours. I force carbed at 20 psi for 5 days at about 70 degrees, shaking the keg daily. I put it in the kegerator at about 40-42 degrees and 10psi. The first glass came out really nice. About 5-6 hours later I poured a glass for my wife to taste and it seemed flat. I upped the psi to 20 overnight. Its 7ish am now so I will wait to check it til later. However, I think even if I lower the psi to 10 its still not right according to the chart. Help!

 

[petemoss]

Ok, I guess this is a pretty dumb question, but how do you read this chart? http://www.kegerators.com/carbonation-table.php I have a porter on tap and it seemed to go flat after a few hours. I force carbed at 20 psi for 5 days at about 70 degrees, shaking the keg daily. I put it in the kegerator at about 40-42 degrees and 10psi. The first glass came out really nice. About 5-6 hours later I poured a glass for my wife to taste and it seemed flat. I upped the psi to 20 overnight. Its 7ish am now so I will wait to check it til later. However, I think even if I lower the psi to 10 its still not right according to the chart. Help!

At 40 degrees and 10 psi, I would have though that you would have been in pretty good shape, assuming the beer was already carbed, which it seems to have been.

According to the chart, you would have an equilibrium carbonation of 2.3 volumes, which in my mind would be pretty good. Perhaps after your force carbonation routine you had more than this amount of carbonation. If you enjoyed it at that level, when it dropped back down to equilibrium it just seemed flat?