Undercarbed or Overcarbed Kegs?

[Davey_Boi]

Got a new keg setup and I am pouring foam! Problem is that the beer still seems flat - even when I back off the pressure and manage to pour without much foam. Here some background on my setup & process:

1 CO2 bottle, 2 kegs, 2 taps, gas lines with splitter taps to each keg. Serving line is 3m / 9ft long. Beer temp when carbing 9 degC / 48 f (my kegerator temp indicator was out so the beer was a little warm).

Carb method as per Kegking.com.au website (where I bought the setup from) which is:
Step 1: Gas turned to 40 psi, turn keg upside down and rock back and forth for 60 seconds.
Step 2: Regulator off, rock until pressure reduces to a stable level (30 sec) aiming to hit a target pressure of 20-23psi. Repeat Step 1 for 15 sec if pressure is less than this.

So I've repeated Step 1 (15 sec) about 4 times after the initial 60 sec, each time with the pressure eventually stabilising at a slightly higher level until I reach ~20psi. I've been testing the beer between each repetition and the carb level seemed low but gradually increasing, until the last time when I suddenly poured a heap of foam!

I left overnight at 8 psi and also got the fridge temp down to 5 degC (lowest I could get it). 24 hrs later it was still foamy and flat at 12psi, but when turned down to 2 psi there was an acceptable level of foam (normal amount of head) and the carbonation was better but still extremely low!

It seems overcarbed since I cant pour at normal pressure, but also seems flat. Is there any other reason for heaps of foam other than being overcarbed? Or is it going flat because it is overcarbed? I guess I either need to increase or decrease the pressure, but which one?

Any help from the gurus is massively appreciated. I have a party in 3 days time and must be operational!

 

[Gameface]

It takes time for the CO2 to be absorbed into solution. You can do it the way you did, but it isn't the same as setting it at ~12psi and leaving it for a week. Mostly because you're intentionally overshooting your target level of CO2 and will have to slowly work your way back down.

If you bleed off the excess pressure and set it to 12psi you'll probably be ok in a few days.

 

[AnOldUR]

Step 1: Gas turned to 40 psi, turn keg upside down and rock back and forth for 60 seconds.
Step 2: Regulator off, rock until pressure reduces to a stable level (30 sec) aiming to hit a target pressure of 20-23psi. Repeat Step 1 for 15 sec if pressure is less than this.

Step 1 will put beer in your gas line. Even if you have a check valve to keep the fluid out of your regulator, having stale beer in you gas line is not a good thing. I would never suggest shaking, rocking or rolling. Fipping the keg over is out of the question.

Letting it sit at 30-40psi for 24 hours (more or less) at basement temperature before moving to fridge at serving pressure is about as radical as I get if I need the beer a little sooner.

Setting to serving pressure and temperature and forgetting it for a week is the best way to go.

For over carbed beer I'd leave it on gas at serving pressure but pull the relief valve a few times a day. This will prevent it from getting flat while at the same time relieve the excess CO2 from the head space as it comes out of suspension and approaches equilibrium.

It can take longer to fix an overcarbed beer than carb it with patience in the first place. Good luck.

 

[Davey_Boi]

Is there any way of being sure it is overcarbed? Or is that a given due to the foaming?

 

[Yooper]

Is there any way of being sure it is overcarbed? Or is that a given due to the foaming?

It's a "given" due to the foaming, plus rocking it at like 40 psi! If you must shake (and I never, ever, ever do), then never shake or rock it at higher than your desired carb level! If it stabilized at 20 psi, that means that is the carb level.

Carbonation is also temperature dependent. 20 psi at 5C will not be overcarbed once it's settled down, but when it's changing temperatures the carb level will also change.

Here's a carbonation chart to help you figure what pressure you want based on temperature (but it's in farenheit, sorry!): http://www.kegerators.com/carbonation-table.php You can see that 40 psi at 48 degrees is off-the-chart overcarbed!

For now, just keep it in one place and turn off the gas and pull the pressure release valve everytime you think about it. Then, tomorrow, reset it for the correct psi and let it sit. It should settle down and be fine in a few days.

 

[JKoravos]

Dissolving CO2 into a liquid is like dissolving sugar into a liquid (except the sugar won't come out if you shake it), you want to mix the liquid as you add the gas. If you add 1 pound of sugar to 1 gallon of water all at once and let it sit it will eventually dissolve but it might take a few days, now if you add the same sugar to the gallon of water and stir it, it will only take a few minutes. That is what you are trying to do, keep the beer well mixed, without splashing, while adding your gas.


Much better method:

1.) Get your beer to the serving temperature, or barring that, as close as you can get to it.
2.) Connect gas at your serving pressure. (at 9C, you probably want to set your reg to 17-19psi)
3.) Very gently rock the keg for 3-5 minutes. DO NOT SPLASH THE BEER IN THE KEG. If you can hear it sloshing you're doing it too hard. Laying it on its side with the gas post at 12o'clock will make it less likely that you get beer in your gas line. Rocking it back and forth a few degrees (like a see-saw) works better, but you may end up having to clean your gas line. Remember: You are trying to gently mix the beer, not shake it.
4.) Taste the beer and repeat until you get to the desired level.

I rarely do this, but in my experience, it can take quite a while to get it to stabilize. Once you get used to it you can probably overpressure to get where you want faster, but you have to be really diligent about checking it every few minutes.

When you take a sample, bleed the pressure down until you get a slow pour to take out the foaming angle. That will give you a better idea of how much carbonation your are actually getting. Once the beer tastes like it has good carbonation, dial in your beer line restriction to get the proper pour.