It depends on how much beer line and what diameter that line is as to what pressure you can keep in the keg to deliver a beer with the carbonation and rising bead you want. I have flow control taps, and use 3psi (at 11C) to carbonate my ales. To get this dispensed at a sensible rate I use 18" (I could use longer) of 3/8" Beer line and the flow control is turned fully open. To dispense Lagers and Ciders (Still at 11C) I use 15psi and 24-36" of 3/16" Beer line, and regulate the flow a little bit with the flow control. . . . It takes around 25-30 Seconds to fill a pint glass . . . but it retains the carbonation which is good.
Remember that if you are using mixed gas you have to be aware that your pressures must be much higher otherwise you will end up with a under carbonated beer. If for example you are using 70/30 mixed gas you only have a 30% as much CO2 as you have with just standard pure CO2. Therefore you need to increase your pressures accordingly so rather than using say 10 PSI you have to use close on 20 PSI to get the same level of carbonation. Why is there no mention of the nitrogen content is actually very difficult to get nitrogen to dissolve in a liquid it doesn't do it but not to the same extent that CO2 does. The degree to which the beer will carbonate does depend on the partial pressures of the gases in the mix. If these are 70/30 in the head space then in theory they will be 70/30 in the liquid unfortunately because they don't dissolve to the same extent things are slightly more complex. So unfortunately you cannot apply the ideal gas equation, but starting with approximately double the pressure you would use the CO2 is a reasonable assumption of a starting point. This can be adjusted up and/or down later as required. Of course you must apply the caveats from above, you need to correct line lengths to enable you to dispense at a reasonable rate but still retain the carbonation.
Also is there a specific way to do it, (steady chaps) like when you are carbonating beer?
Thanks for that.
