Frustrating under-carbonation issue with keezer

[Narapoia]

Hi All,

I bought a keezer setup a couple months ago and have been having issues with low carbonation of the beer at the tap. The Keezer has 5 taps, a 5 way gas manifold and an external C02 bottle. The lines to the taps are EVA barrier 4mm ID (8,, OD) to nukataps. I've read a bunch about balancing a keezer system but I must be missing something as the beer is coming out much less carbonated than the Irish red ales I previously bottled where I aimed for 4.8 g/L C02, but I'm looking for circa 5.2-5.4 g/L.

System setup for carbing:
- Mk 2 Temp controller with the probe up against the side of the keg under bubblewrap keeping it at 4 C.
- Regulator set to around 14 psi (Which according to the various carbonation tables I've looked at should give around 5.4 g/L.
- Set and forget - keg has been at these settings for 3 weeks. I don't have a carb stone and didn't rock/agitate the kegs at all.
- Using a mix of 9.5 and 19L kegs

For Serving:
- Calculated using 12psi serving pressure
- 5 ft lines to the taps based on height of taps vs keg mid point, line diameter and pour time of 11 seconds for a pint

I don't think there's a leak in the system as it's been set up with at least 1 keg and under pressure for the last 2 months and there's still CO2 in the bottle. I don't think there is an issue with the regulator as it takes about 11 seconds to get a pint from the tap at 12 psi.

Has anyone battled with anything like this before or is there something I am missing? The previous owner didn't mention anything around carbonation and actually has longer lines to the taps that I replaced with the 5 ft ones. The first half pint poured is very poorly carbonated which would be expected as the tap is a bit warmer, it's a bit better after that but still much less carbed than my bottle conditioned beers at the target CO2 volume.

Is quite frustrating - am in the process of brewing a lot of beer for a mate's 40th at the end of Sept that will be served from this setup and can't quite seem to get this variable down.

ETA - in terms of the pours - there's a bit much foam on the first half pint as the tap cools down. From there there's a decent head on the beer, nothing excessive or underwhelming, it looks like it should be nicely carbed but it's just a bit flat.

 

[elmoMakesBeer]

My technique is to turn the reg pressure up a wee bit if I find my beer is less carbonated than I like. Turn it down if it’s overcarbed. I don’t change more than once every few days (to give it time to stabilise in the keg), then leave it alone once it’s to my liking. The pressure on the gauge is ~20-30% greater than it “should” be according to charts. Maybe it’s because of the pressure drop over the check valve. Maybe the gauge is out. Maybe my desired carbonation level is “wrong” according to some guide. I really don’t care - the beer carbonation suits me and others who drink my beer.

 

[clickeral]

Check valves will drop your pressure by around 2psi per valve but if I was investigating I would be doing the below

1. Check and confirm that you have no leaks
2. Get another gauge to check the pressure in each keg
3. Confirm the gauge on your regulator is accurate

How long have the kegs been in the keezer? have you got another way to validate the temp

 

[Half Pint]

It has to be your regulator gauge or your temperature control.
My money is on the gauge.
There’s a very limited range of possibilities to explain the situation. If the beer is at a given temperature it will hold as much gas as is commensurate with the pressure applied, so it’s either too warm or the pressure is too low.

 

[TwoCrows]

If you believe you have carbonated to desired pressure.

If you disconnect all C02 lines from the kegs and turn off the C02 bottle valve and the pressure gauge falls to 0 PSI you have a leak in the system.

When you want to test the keg is at the correct set pressure, connect the set gauge C02 line and turn off the bottle valve, if the pressure gauge falls to 0 PSI it is not at the desired pressure or keg is leaking.


My 4mm lines for serving are 2.3- 2.5 mtrs long.

Put a bottle of water in the keezer and test the temperature with a known good thermometer.
If you have a spunding valve and gauge you can test each kegs pressure.

 

[Narapoia]

Check valves will drop your pressure by around 2psi per valve but if I was investigating I would be doing the below

1. Check and confirm that you have no leaks
2. Get another gauge to check the pressure in each keg
3. Confirm the gauge on your regulator is accurate

How long have the kegs been in the keezer? have you got another way to validate the temp

Thanks for the reply.

1. I've left the system as one of the other posters suggested with the C02 bottle closed and the lines under pressure for a few days, without any drop in pressure being registered on the gauge - stayed bang on the 12 psi it was set to the whole time. Plus it's been connected up for a couple months now.
2. Just got a spunding valve this week - keg pressure is circa 12 psi with 14 psi set on the reg - with the inbuilt check valves on the manifold that means the reg is probably accurate. I didn't realise there was a pressure drop across the manifold. However carb table says it should still be around 5g/L CO2 at this pressure in the keg and it doesn't seem that well carbed
3. Reg seems about right.

In terms of the temperature - have checked with another thermometer, not a calibrated one but it agrees with the Mk 2 temp probe and readout.

Maybe it's just this 2 psi difference. Have put the reg up to 16 psi, will give it another week and see what that does.

 

[Narapoia]

My technique is to turn the reg pressure up a wee bit if I find my beer is less carbonated than I like. Turn it down if it’s overcarbed. I don’t change more than once every few days (to give it time to stabilise in the keg), then leave it alone once it’s to my liking. The pressure on the gauge is ~20-30% greater than it “should” be according to charts. Maybe it’s because of the pressure drop over the check valve. Maybe the gauge is out. Maybe my desired carbonation level is “wrong” according to some guide. I really don’t care - the beer carbonation suits me and others who drink my beer.

I'm definitely going to take this approach. The check valves do play a role, but beer seems less carbed than it should be even taking this into account.

 

[Narapoia]

It has to be your regulator gauge or your temperature control.
My money is on the gauge.
There’s a very limited range of possibilities to explain the situation. If the beer is at a given temperature it will hold as much gas as is commensurate with the pressure applied, so it’s either too warm or the pressure is too low.

This is what I had landed on as well but wanted to confirm I wasn't missing something. It does appear that I was missing the pressure drop across the check valve, though as mentioned in one of the other replies the beer isn't the same as bottle conditioned beer at 5 g/L C02 that I would expect from 4 C and 12 psi in the keg. Temperature seems to be right, same readout from another test thermometer

Anyway - have upped the pressure and will see how that goes in a week or so.

 

[Narapoia]

If you believe you have carbonated to desired pressure.

If you disconnect all C02 lines from the kegs and turn off the C02 bottle valve and the pressure gauge falls to 0 PSI you have a leak in the system.

When you want to test the keg is at the correct set pressure, connect the set gauge C02 line and turn off the bottle valve, if the pressure gauge falls to 0 PSI it is not at the desired pressure or keg is leaking.


My 4mm lines for serving are 2.3- 2.5 mtrs long.

Put a bottle of water in the keezer and test the temperature with a known good thermometer.
If you have a spunding valve and gauge you can test each kegs pressure.

Thanks for the suggestions here - I tried both the methods you suggest for leak checking and pressure was maintained in both cases.

Interesting - do you have a keezer or kegerator? Your line length is a bit closer to what the original setup was for this Keezer. I'm not getting very foamy pours with the shorter line lengths, but I'll leave the system at slightly higher pressure for another week and see how it pours then.

 

[TwoCrows]

I have a fridge 490 ltr. It is the back fridge for milk and cans/bottles. I need the freezer of BBQ and hops.
Holds 3 x kegs and the bottle.


Have a look beer line length starts @ 5:00

 

[elmoMakesBeer]

I'm definitely going to take this approach. The check valves do play a role, but beer seems less carbed than it should be even taking this into account.

This works for me. But remember to raise the pressure just a little bit (1-2psi max at a time) then don’t touch the pressure for a few days to let it stabilise. It is easier to increase carbonation to an under-carbed beer than it is to reduce carbonation in and over-carbed beer (but this is possible too - disconnect the gas and pour yourself a beer or just depressurise the keg, then check again in a few days). You have time to work it out before the event. Once you do, leave the pressure alone.

 

[Narapoia]

This works for me. But remember to raise the pressure just a little bit (1-2psi max at a time) then don’t touch the pressure for a few days to let it stabilise. It is easier to increase carbonation to an under-carbed beer than it is to reduce carbonation in and over-carbed beer (but this is possible too - disconnect the gas and pour yourself a beer or just depressurise the keg, then check again in a few days). You have time to work it out before the event. Once you do, leave the pressure alone.

Definitely - I've bumped it up 2 PSI for now - will try again next weekend and go up in 1 psi increments from there if required. Everything I've read agrees with you re: overcarbed beer being a hassle - so I have been hesitant to crank up the pressure till I understood what is happening.

Thanks for the help - should have enough time to work it all out.

 

[clickeral]

What taps do you have?

 

[Narapoia]

What taps do you have?

They are all Nukataps.

 

[KegLand-com-au]

It might be worth noting that if you set the temp to 4C that doesn't mean your beer is 4C. For instance your temp controller will only start cooling when
current temp = set tup + hysteresis setting

so if you have your hysteresis setting is 3C for instance then it means your compressor will turn on at 7C and turn off at 4C. so your beer will average at 5.5C

Also I see you have a thermostat that is already in the fridge too. If that thermostat is set to higher than 4C then you will never get to 4C. If you are using the MKII Temp controller then you would be better off bypassing the internal thermostat all together so all control of the temperature is done with the MKII temp controller.

It looks like everything else in your setup is looking good but I am guessing that your temperature is too high. Also if you have maybe overfilled the kegs then this can be a problem too as an overfilled keg has little to no surface area between the gas and liquid. The speed of carbonation is a function that takes into account the gas/liquid surface area.

For $1.20 this is also not a bad purchase:
https://www.kegland.com.au/products/the-kegland-carbonation-chart-sticker
(alternatively go to the PDF link and you can just print it out yourself as it's handy to have on the inside wall of your fridge or kegerator door.

 

[Narapoia]

It might be worth noting that if you set the temp to 4C that doesn't mean your beer is 4C. For instance your temp controller will only start cooling when
current temp = set tup + hysteresis setting

so if you have your hysteresis setting is 3C for instance then it means your compressor will turn on at 7C and turn off at 4C. so your beer will average at 5.5C

Also I see you have a thermostat that is already in the fridge too. If that thermostat is set to higher than 4C then you will never get to 4C. If you are using the MKII Temp controller then you would be better off bypassing the internal thermostat all together so all control of the temperature is done with the MKII temp controller.

It looks like everything else in your setup is looking good but I am guessing that your temperature is too high. Also if you have maybe overfilled the kegs then this can be a problem too as an overfilled keg has little to no surface area between the gas and liquid. The speed of carbonation is a function that takes into account the gas/liquid surface area.

For $1.20 this is also not a bad purchase:
https://www.kegland.com.au/products/the-kegland-carbonation-chart-sticker
(alternatively go to the PDF link and you can just print it out yourself as it's handy to have on the inside wall of your fridge or kegerator door.

Thanks for the post. In terms of the fill - it's below the level of the gas in post, so before the curve in the keg starts and hopefully the surface area isn't much of a factor. Though the time it takes for beer to carb/stabilise seem out of line with other people so maybe it is a bit high and that's making it take longer.

I have the Keezer set to -15 C, the MK2 controller set to 3.4C with 0.6C hysteresis so the max temp should be 4C. I might set it lower and increase the hysteresis so the compressor is on less often but with the same mac temp of 4C. I have another thermometer that I use for mashing etc that used to compare the readout I was seeing on the Mk2, rather than relying on the keezers thermostat.

 

[djebel]

@KegLand-com-au I think this is the link you meant to post .

https://www.kegland.com.au/products/the-kegland-carbonation-chart-sticker




And here is a direct link to the PDF mentioned above.

https://www.kegland.com.au/cdn/shop/files/KegLand_Carbonation_Chart.pdf

 

[Hangover68]

I use an inkbird with my keezer set on 2C, i use the large eva hose for gas which i think is 9.5mm od ?

 

[bjay]

I have 2 x co2 bottles that will not shut of with the bottle valve , They still leak pressure one worst than the other
Not sure if this is your problem , Just disconnect kegs then release gas from reg , And see if it builds up again without reconnecting kegs
Pretty easy to check if you are running out of ideas

B

 

[TwoCrows]