Author Topic: nitrogen/co2 carbonation and despensing beer  (Read 535 times)

Offline letterc

  • 1st Kit
  • *
  • Posts: 7
    • View Profile
nitrogen/co2 carbonation and despensing beer
« on: January 22, 2014, 08:48:29 PM »
How do I infuse nitrogen into my beer, I have set up the equipment, I carbonate at 30 lbs pressure
for 7 days, I get one pint which is just great with the nitrogen effect and creamy head, the following
draws are all flat, no nitrogen effect. I am using 75/25 mix also using a stout faucet. I am serving a dark
porter. Any suggestions?

Letterc

Offline Jeff M

  • Brewmaster
  • *****
  • Posts: 821
  • Currently upgrading to Brewery 3.0
    • View Profile
Re: nitrogen/co2 carbonation and despensing beer
« Reply #1 on: January 22, 2014, 08:54:11 PM »
This is from a different site.  I dont have any experience with nitro mixes.

I generally force carbonate my beer straight after a period of cold crashing - so it will be pretty clse to 0 deg C.

The process for force carbonating a beer in preparation for serving for nitrogen is just a shortened version of how I normally force carbonate as described below:

1. Set your Co2 pressure to about 40-45psi and connect to the keg.
2. Force air out by bleeding keg through release valve.
3. Invert the keg and shake/roll to encourage the dissolution of co2 into the beer.
4. After a while (more on this below), turn the keg the right way up, close the tap on the co2 tank then roll/agitate the keg on it's base to allow the pressure in the headspace to disperse into the beer and to equalize.
5. By watching where the pressure gauge finally settles as you agitate the keg, you will be ale to see how much pressure you have forced into the beer thus far.
6. Repeat from step 3. until the equalized pressure is at or just below the target carbonation for your beer.

Non nitrogen beers still benefit from 4 - 5 days conditioning as the carbonation becomes finer and less soda-like. Nitrogen served beers seem to be fine right there and then as the nitrogen has a much finer mouthfeel than Co2 to start with. As I mentioned earlier, the nitrogen masks a lot of flavour too (seems to be the defining characteristic of 'smooth-pour' beers), meaning that it's drinkable sooner.

Regarding how long to agitate for: It takes a bit of experience to know how long to 'force' it for before measuring it but it's generally a couple of minutes for a higher carbonated beer or for the aforementioned stout, about 30 seconds. In any case, dropping the pressure is a matter of letting the beer sit for a day or 2 with the release valve twisted open.


I use a nitrogen mix of 20% Co2/80% N - here in NZ its called Cellamix 12. There are other versions with higher Co2 and they are also used for serving stouts and other smooth pour beers - but it was explained to me that one of the main uses for the higher Co2 mixes was to maintain the pressure of beers in kegs for a long time without the risk of overcarbonation, which seems to happen with partially full kegs left at servig Co2 pressure.

[EDIT] Forgot to mention that you will need to hold the keg pressure at much higher levels with nitrogen mixes - basically, the less Co2, the higher the pressure. I leave my 20/80 mix at around 30-35psi. Guinness recommend 20/80 mix at 40psi but I find this results in with too much head on the beer after a week or so in the keg.
Granite Coast Brewing Company.
Building a clone of The Electric Brewery to use as a pilot system for new recipes!

Offline letterc

  • 1st Kit
  • *
  • Posts: 7
    • View Profile
Re: nitrogen/co2 carbonation and despensing beer
« Reply #2 on: January 24, 2014, 07:07:43 AM »
Thanks for the info I have moved my keg to the freezer box and will leave it there at 30F for a week
then try to carb again by shaking and rolling the keg at 40 lbs and serve at 30 lbs.
Letterc

Offline brewbaker

  • 1st Kit
  • *
  • Posts: 10
    • View Profile
Re: nitrogen/co2 carbonation and despensing beer
« Reply #3 on: January 24, 2014, 08:21:56 AM »
This is no different than normal CO2 carbonation, it just requires some basic math.

First, decided what level of CO2 you want in your beer. Use this chart: http://www.zahmnagel.com/LinkClick.aspx?fileticket=HuVGZ8tLaow%3D&tabid=81

I shoot for 2.5 volumes at my 39F serving temp (personal preference on both of those, no need to go any further. I like my beer a bit colder and like to let it warm up over the course of a pint, but I digress.)

At 39F and 2.5 volumes of CO2 I need 12psi for 100% CO2. With my beer gas mixture being 25% CO2, all you need to do is multiple by 4 (25%*4=100%). BANG. Done. Set my serving pressure to 48psi and let it sit and carb up. (you can shake it for a couple minutes as well when set at the pressure and it will carb up faster or you just wait a week).

That is it. It really is as simple as that.

Another example. You have a serving temp of 45F and you want to go on the high side with 3 volumes of CO2. Go to your chart, at 45F and 3 volumes you need a psi of 21 for 100% CO2. Multiple by you beer gas ratio (if it is 20% CO2 x5 if 25% x4). So for 20% beer gas, 21x5 = 105psi. Now that is a bit high, like I said.

Final example. With nitro, you probably want to go on the lower side (honestly I think 2.5 is pushing it but that is what I like.) so 2 volumes at 40F serving temp. Go to the chart, you find to reach 2vol at 40F you need 7psi with 100% CO2. 7x5 (for 20% beer gas) and you get 35psi.


If you have any more questions, post 'em. But it is so simple to dial it in exactly like you want with minimal effort there is no reason to roll or invert kegs. Just calculate your pressure, purge the 02, shake just a bit (optional), and let it sit for a couple days.