Flat beer at end of keg. Is this normal?

[TheKernalWixen]

G'day,

I've recently built myself a bar running a flooded dual font via a ice bank chiller unit (Icemaster G40) cooling at -4'C and have noticed my kegs getting flat over time. I carbonated both kegs at approx 2'C at 350Kpa for 24hrs in my fridge and since have moved them outside to my keg storage area under the bar that has a PC radiator fan unit cooling at fluctuating ambient temps due to current heat wave in Melbourne. I don't believe that i have any leaks in my gas lines and I do turn off the supply once I've finished pouring beers for the day. Am I right in assuming that due to the ambient temperature difference in the now stored keg area to when it was first carbonated 2'c vs 20'c that all I should do is re-gas them?

I did find a similar topic and it was suggested to re-gas the keg(s) and I managed to find a carbonation chart to pressurize at 187Kpa at 20'c (this is how I interpreted it) but it does not recommend for how long in doing so. I don't force carbonate due to hop bombing my kegs.

Any help would be greatly appreciated.

Kernal.

 

[Tropico]

From what I understand in your post, after carbonating, your kegs are stored under you bar at ambient temps, is that right? If so, you should keep you kegs chilled. Temperature verse pressure and all that stuff.

 

[mxd]

Assuming you don't have a leak.

you need to look at balancing your system, and the carbonation chart you found may be correct, the cooler the liquid the easier it is to absorb the co2.

if you carbonate your beer at 2 degrees then leave it at 20 degrees the co2 will leave the beer and go into the headspace, so you'll potentially have a very quick pour or you have the right length line or flow control taps. If your chart is right, then what you need to do is carbonate the beer as you do, when you pull it out add the pressure up to 187kpa which will keep the carbonation "balanced", then when you pour beer etc.. turn gas on and leave it ate 187 kpa.

IMHO it's best to keep beer at a "lower" temp than 20 to give it every chance to stay "fresh"

 

[timmi9191]

Do you have co2 connected to kegs outside? or are you just using the keg pressure to pour?

If using keg pressure, every time you pour you are robbing the keg of the co2 to keep the beer carbonated. the pour will slow and eventually beer will go flat.

 

[TheKernalWixen]

From what I understand in your post, after carbonating, your kegs are stored under you bar at ambient temps, is that right? If so, you should keep you kegs chilled. Temperature verse pressure and all that stuff.

My kegs are stored under the bar in a fabricated cool room via a PC radiator fan at approx 12-20 degrees depending on outside ambient temperature. The pump from my icebank chiller flows though the radiator and fans draw air from the now chilled radiator into the keg storage area. Kegs are poured through a flooded font via a icebank chiller (Icemaster G40)

Do you have co2 connected to kegs outside? or are you just using the keg pressure to pour?

If using keg pressure, every time you pour you are robbing the keg of the co2 to keep the beer carbonated. the pour will slow and eventually beer will go flat.

I use a 9kg Co2 bottle that I use to both carbonate in my fridge at 2'C and pour beer with in the bar. My main question is under counter fluctuating coolroom storage temps due to outside ambient temperatures resulting in flat beer in my keg with consumption.

 

[TheKernalWixen]

@MXD

I carbonate at 2'C at 350kpa for 24 hrs. The full kegs are then stored in the cool room to mature, bled off and poured through the icebank chiller and flooded font with Caulfield (DA) taps in the bar outside with a 9kg Co2 bottle and pour pressure adjusted with the regulator set approx 80-100kpa (pouring at 187Kpa is not ideal with my setup as get to much head off the pour.) My main problem is loss of carbonation over time (2-3 weeks) with consumption, which I think you touched on with the Co2 going to headspace. I'll leave the gas on overnight set at 180Kpa and see what happens... as coolroom temps at 14'C

 

[mudd]

You need the higher pressure to keep carbonation up at such a storage temp. To compensate you need to balance your system ie. restrict the flow by using longer lines &/or smaller internal diameter lines.
Cheers

 

[TheKernalWixen]

You need the higher pressure to keep carbonation up at such a storage temp. To compensate you need to balance your system ie. restrict the flow by using longer lines &/or smaller internal diameter lines.
Cheers

Thanks for the info MUDD.

Ive got myself a gas manifold that isn't hooked up yet to divert pressure to each keg by restricting and manual flow adjustment via ball valves other then regulated pressure. Currently use 8mm OD tube with john guest quick connects, so from the Co2 bottle regulator outlet it goes into a check valve, a T piece then to the ball valves to each keg (2) Gas line length is approx 600mm in total.

Would like to know some more information regarding "balancing" What i gather from what your saying is, run higher pressure (187Kpa) and to eliminate over carbonation while pouring ill need longer or smaller gas lines? Will this solve my problem with loss of carbonation with kegs in storage?

 

[timmi9191]

not gas lines, beer lines.

higher pressure gas will increase flow rate of beer and at too high of a rate will pour foam. so to balance the high pressure on the gas side, either run longer beer lines or smaller ID lines to reduce the flow rate.

do a search of the forum for keg balancing, lots of info including charts for different pressures/lenghts and temps

 

[timmi9191]

some quick calculations at 187kpa, you should use approx 5m of 5mm internal diameter beer line.