What causes kegged beer to go flat soon after pouring?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

hotbeer

Opinionated Newb
HBT Supporter
Joined
Mar 10, 2021
Messages
1,443
Reaction score
1,029
I was visiting another last week and their kegged beers seemed to have plenty of carbonation when poured, but didn't seem to hold that carbonation very long. On the other hand, my naturally carbonated bottles I took with me stayed carbonated a long time after pouring.

Is this just the CO2 pressure that is maintained on the keg system or something else? With all the head the beers were producing I'd be hesitant to say they needed more carbonation.

This was stout vs IPA. Is it more normal for stout to go flat quicker?
 

tracer bullet

Supporting Member
HBT Supporter
Joined
Aug 10, 2020
Messages
1,491
Reaction score
1,287
Location
Minnesota
Stouts are typically carbonated less than their IPA counterparts.

Head can also be a function of the tap and how it's poured and not always an indicator of carbonation level.

Your bottles could be carbonated more than "normal" and not a good comparison. Could be fine but if that's the case it isn't a bad thing just that what you are used to and enjoy may also not be the norm.

Even bars don't necessarily get it "right".
 
Last edited:

day_trippr

Structural Duct Tape Sales Engineer
Joined
May 31, 2011
Messages
38,656
Reaction score
21,850
Location
Stow, MA
I was visiting another last week and their kegged beers seemed to have plenty of carbonation when poured, but didn't seem to hold that carbonation very long. [...]
With all the head the beers were producing I'd be hesitant to say they needed more carbonation.

There is only so much dissolved CO2 in beer, and it sounds like their dispensing system is poorly tuned and their beers are losing carbonation to excessive foam.

This was stout vs IPA. Is it more normal for stout to go flat quicker?

Stouts are typically carbonated to roughly 1.2-2 volumes, while IPAs are typically carbonated to ~2.5 volumes, so certainly the stouts have less to lose...

Cheers!
 
OP
OP
hotbeer

hotbeer

Opinionated Newb
HBT Supporter
Joined
Mar 10, 2021
Messages
1,443
Reaction score
1,029
I got a look inside his kegerator. The tubing between the kegs and the taps seemed a little narrow diameter to me. But I wasn't in there to inspect and analyze so maybe it just appeared narrow.

Might that be an issue for the Tap and getting a smooth pour? Also not entirely sure why he left the tubing long and coiled up. I'd have thought just long enough would be better.
 

Yooper

Ale's What Cures You!
Staff member
Admin
Mod
HBT Supporter
Joined
Jun 4, 2006
Messages
75,015
Reaction score
13,043
Location
UP/Snowbird in Florida
I got a look inside his kegerator. The tubing between the kegs and the taps seemed a little narrow diameter to me. But I wasn't in there to inspect and analyze so maybe it just appeared narrow.

Might that be an issue for the Tap and getting a smooth pour? Also not entirely sure why he left the tubing long and coiled up. I'd have thought just long enough would be better.

Usually, longer is better so it sounds ok. But it depends on the rise to the tap, the setting of the regulator, the diameter of the tubing, the length, and the beer carbonation level. Since stouts are generally not very carbonated, maybe it's fine and just seems low?
 

day_trippr

Structural Duct Tape Sales Engineer
Joined
May 31, 2011
Messages
38,656
Reaction score
21,850
Location
Stow, MA
lol - I'm confused. Which beer was on tap and which was bottled? 🤔

[edit] nvm, figured it out. As I mentioned earlier, a stout is typically carbonated to a lower level than an IPA. But if that carbonation is being lost in a collapse of foam, the system isn't tuned properly...

Cheers!
 
OP
OP
hotbeer

hotbeer

Opinionated Newb
HBT Supporter
Joined
Mar 10, 2021
Messages
1,443
Reaction score
1,029
NEIPA was bottled. The Stout was kegged. It just seemed to me the Stout went flat way too soon before I finished a 12 oz glass of it.

And I wasn't really trying to make it last. There was more beer to be had. But each time I got a glass of the Stout, it just seemed to go flat before I finished drinking.
 

tracer bullet

Supporting Member
HBT Supporter
Joined
Aug 10, 2020
Messages
1,491
Reaction score
1,287
Location
Minnesota
Can't really help someone else's setup without knowing how it was set up. It's probably not the lines alone, though. Maybe regulator set low, maybe beer not very old, maybe poured in such a way all the carbonation blew off at once. Who knows.

Have them join and ask, if they need help :)
 

TheMadKing

Western Yankee Southerner and Brew Science Nerd
HBT Supporter
Joined
Jun 17, 2015
Messages
3,952
Reaction score
2,133
Location
Gainesville
NEIPA was bottled. The Stout was kegged. It just seemed to me the Stout went flat way too soon before I finished a 12 oz glass of it.

And I wasn't really trying to make it last. There was more beer to be had. But each time I got a glass of the Stout, it just seemed to go flat before I finished drinking.

So stupid question maybe.. But was the stout on nitro?
 

bwible

I drink, and I know things
HBT Supporter
Joined
Oct 31, 2017
Messages
2,163
Reaction score
4,294
Location
Oxford, PA
Carbonation is a function of CO2 pressure, temp, and time. There is a chart we all use for this.

Could be that it wasn’t in the keg under pressure very long. Could be the keg has a slight leak somewhere and is not holding all of the pressure. Could be the amount of pressure being applied is not enough.

I do not leave my beers on gas all the time, in the event of any small leak so that my CO2 bottle won’t get completely drained. I shoot my beers multiple times and turn the tank and valves on and off each time.
 

ScrewyBrewer

ezRecipe - The Easy Way To Awesome Beer!
HBT Supporter
Joined
Jun 5, 2010
Messages
2,001
Reaction score
580
Location
New Jersey
@hotbeer

If your beer is too 'thin,' the lacing and head retention will not last long once poured. Hops, Crystal malts, and wheat or oats added to a recipe will improve head retention, as will mashing at higher temperatures 152F - 156F and maintaining a mash near 5.4 pH.
 
OP
OP
hotbeer

hotbeer

Opinionated Newb
HBT Supporter
Joined
Mar 10, 2021
Messages
1,443
Reaction score
1,029
Maybe it's just that it's been a long time since I've had a stout. The taste was good. But toward the end the missing carbonation made me want to simply toss it away and get fresh. However I didn't because the frugal part of me wouldn't like the semblance of being wasteful.

The beer had been kegged for some time. CO2 only, no nitro. I'm not big on head on a beer or head retention. If it has one fine, but if it goes away quick and lets me be able to drink my beer without having to behave with wine snobbishness involved then even better.

Glasses were the same and clean and multiple glasses drawn over several days of visiting.

CO2 pressure I won't know. Nor holding temp, though it was cold beer.

I was mainly just curious if this was a thing with kegged beers in general or just the circumstance of this beer in particular.

Might it be more likely that if the CO2 pressure is too high that the beer is over carb'd and that causes it to go flat sooner? I have one batch of naturally carb'd beer that are volcanos. They go flat almost as soon as the volcano ends.

Though these didn't seem to have excessive head for a stout. But then it might get back to what someone said about how the tap is "tuned" with the system.
 

Beermeister32

Supporting Member
HBT Supporter
Joined
Jul 20, 2013
Messages
1,294
Reaction score
2,163
Location
Southern California
I have one batch of naturally carb'd beer that are volcanos. They go flat almost as soon as the volcano ends.
I’d get those bottles refrigerated and COLD as quickly as possible to avoid bottle bombs. Drink them up now.

If you have to store them at ambient, get a big plastic tub with a lid and put the batch inside for safety. Put some weight on the lid to make sure it stays closed.

If you are careful, you can pull up a little edge of the bottle cap and let the CO2 vent off, then re-cap them after an hour.
 
OP
OP
hotbeer

hotbeer

Opinionated Newb
HBT Supporter
Joined
Mar 10, 2021
Messages
1,443
Reaction score
1,029
I’d get those bottles refrigerated and COLD as quickly as possible to avoid bottle bombs. Drink them up now.

If you have to store them at ambient, get a big plastic tub with a lid and put the batch inside for safety. Put some weight on the lid to make sure it stays closed.

If you are careful, you can pull up a little edge of the bottle cap and let the CO2 vent off, then re-cap them after an hour.
Well they were bottled 4 months ago. I've only 3 bottles left. They are stored where they won't hurt anything if they did pop their own top or simply burst.

Next one I decide to open, I might try getting it colder in the freezer after it's been sitting in the refrigerator for a few days.

For the few I had and the fewer remaining, it's not worth bothering about. I just drink what ever doesn't foam away.
 
Top