Tuesday, November 13, 2012

Nitro

I bought a nitrogen set up from a guy who is getting out of homebrewing. I always thought it would be cool to have one. All the beer on nitro I've had at the various microbrew places has been excellent, including stouts, porters, pale ales, and, of course, cream ales. I didn't know much about it and had some wrong ideas. It's taken me quite a bit of research to figure this out, so I'm putting the notes here for future reference.

The system 

The system I bought was mostly complete. The tank was empty, so I needed to get that filled. Besides the tank, it came with a regulator, hoses, drip tray, and stout faucet. I needed to switch out the ball lock connectors with pin lock connectors to fit my kegs.

Installation 

It turns out there is a lot of very vague and incomplete information on the internet. I can't find any info on the faucet at all. I did find an image, but that's about it. Other than the faucet looks different, the hook up and plumbing is exactly the same as for a regular CO2 set up.

Here are a few shots of the nitro/stout tap installed.The tall handle is going to be a problem. I have the short handles so I can open the freezer section without opening a tap. The knob right behind the handle regulates the flow, just like a faucet. So it is possible to turn off the tap or run it real slow. It turns out this is great for filling bottles and growlers. The more modern Guiness taps don't have this knob. I didn't know about it in advance, just lucked out on getting one with this great feature.




Here is the NO2/CO2 tank in the reefer. I have a 20 lb tanks for my ales, outside of this pic.

Prepping a keg 

This is where I found a lot of conflicting and confusing information. It seems that any beer can be put on nitro. Stouts tend to do better than IPAs, mostly because the nitro will diminish the hops flavors that should be prominent in the IPA. Carb the keg about .5 atmospheres lower than normal. If you're force carbing, set the pressure to about 8 lbs and let it sit until carbed properly. Then connect the keg to the nitro. The pressure should be set to 4 or 5 times what your CO2 pressure was. This is because the beer gas is about 80% nitrogen and 20% CO2. Ask the people that filled the nitro tank exactly what the percentages are. The nitrogen won't absorb into the beer. Well, it will, but only a very little will absorb, so the higher pressure puts the smaller amount of CO2 at the right place to keep the beer carbed. Once the pressure is set, it may take a few days for the system to stabilize and provide proper pours.

 Pouring

The Guinness way is to hold the glass at a 45 degree angle, fill the glass 3/4 full by pulling forward on the tap handle, let it sit 2 minutes to settle (don't rush this step), then top it off by pushing backward on the tap handle. This should make a nice, creamy head about 1 inch tall.

First pour:


Nice creamy head!

Other notes 

  • It will take a bit of playing with to get the knob on the back adjusted right to get a good pour, but it was easy enough to get it right during the first pour. I'm not sure how the newer faucets without the adjustment knob get the flow right, maybe it's all in the tube length?
  • The stout faucet has a restrictor plate in it that can be removed. Just unscrew the spout and it should fall right out. Once removed, the faucet can be used like any other faucet with 100% CO2. Don't use the faucet with the restrictor with a 100% CO2 system. You'll get nothing but foam if you do. 
  • This tap is great for filling bottles or growlers. The knob on the back allows fine tuning of the flow rate out of the tap, so it's easy to turn it down to do a slow pour into a growler. A hose slid up over the spout would help get the beer into the bottom of the bottle with less foaming.
  • Beer gas comes in several proportions. I have 75/25. The rule of thumb is use a mixture with less CO2 for darker beers, more CO2 for lighter beers. So maybe use 60/40 for pouring pale ales, 80/20 for hard-core stouts. The guy at Norco told me 75/25 is the most commonly used in this area.
  •  Supposedly you can hook regular beer with a regular tap to the nitro, but you'll need to do some adjustments to the beer line to make sure the output pressure at the tap is around 2 lbs. Taverns and bars use beer gas all the time to push the beer through the long lines from wherever they have the kegs to their taps. This way they can increase the pressure without over-carbing the beer.
  •  Some people think serving beer with nitro is a substitution for cask ale. Not true, they aren't the same thing at all.

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