Overcarbination in last 1/4 of the keg.

[timmi9191]

First 3/4 of the keg is spot on, but I'm constantly getting the last 1/4 of the keg overcarbed. Pours half a pot of head!

My head is full of ideas like as co2 vol in keg increases absorption increases etc etc but can't find any answers in the google machine..

Any suggestions?

 

[treefiddy]

What temp/pressure do you use?
How long does the keg last?

 

[timmi9191]

3 degrees.. 2 weeks approx give or take.. 12 psi pour pressure.

 

[Neanderthal]

Do you have gas turned on the whole time?



I have started to turn my gas off once carved and turning on when I am after a pint. It's working well.

Save gas loses too.

 

[treefiddy]

My thinking was that your pressure may have been a touch high. The lower volume would become carbonated quicker, hence why the last few days might be overcarbed.

Probably not the case.

New direction! Do you have a fan?

The last 1/4 sits lower to the bottom. If the air is allowed to settle the cold air sinks and cools the beer more. Pressure remains and over carbonates the beer.
Possible?

 

[timmi9191]

Fiddy, u could be on to something..

Just drinking 1 now and thinking, shite that's cold..

 

[mxd]

it's a quick keg and only 3 posts a months since joining

What is the beer line length, height of font etc..

I assume you've used the balancing spreadsheet ?

 

[timmi9191]

Mxd.. I'm a listener not a talker hence the time to post ratio..

Used the balancing spreadsheet.. System starts perfect, just doesn't end that way..

When I've gone camping and keg goes in a day, no such problem..

 

[Kiwimike]

Timmi I find the same thing sometimes, if I remember I unplug the gas when I know the keg is getting low and rely on pressue within to pour. That generally fixes the issue.

I too am a reader rather than a talker! :beerbang:

 

[mikec]

Turn the gas off when you reach the end of the keg, there's enough in there to keep pouring.

 

[Cocko]

I get this very occasionally, in particular when I use my 40L corny.

I have always thought it is a head space issue, not temp - I am not or do I know the science behind it, I am better at doing up bolts, burping and lifting heavy stuff... regardless, I am sure someone here could explain this in more detail but in short, its headspace

If you end up with it pouring as you have mentioned, best and easiest - bleed the keg on your way to bed. the next evening, assuming you dont have beer for brekky, the next day some of the C02 would have escaped the beer, filling the head space and producing some pressure to pour - in other words, you are taking C02 from the over carbed beer and using it to serve and reducing the carbonation of the keg. It is painfully slow to pour but your are doing gods work!

1.4c

 

[treefiddy]

I disagree. The amount of dissolved gas in a liquid is directly proportional to the pressure above the liquid.

Unless your regulator is creeping up, the only variable there is temperature.
The amount of dissolved CO2 will increase at a lower temperature, and the regulator will keep that pressure supplied to over carbonate the beer.

Cocko, you're effectively reducing the pressure of the gas, so when it cools down the further dissolution of CO2 is not favoured.

 

[mxd]

are you in a freezer or fridge, the temp of beer when the volume is lower could be a degree or 2 cooler than a full keg ??