Nitrogen Pour

[BrewHouse]

The next brew on the agenda is a dry Irish Stout and I am keen to try for that smooth creamy Guiness head. I have a bottle of nitrogen but have not yet bought the regulator or anything else. Are there any Stoutheads out there that can give me some advice on setup?

 

[simon12]

I don't have experience on this but I think pure nitrogen is only used to dispense wine or anything else you want completely flat. Guinness is served with a 75% N and 25?% O2 gas and if pure nitrogen was used it would go very flat. If you plan to force carbonate it you need to use a gas that contains at least some CO2 and to dispense it you need the correct pressure and gas mix to ensure the level of CO2 stays the same as its dispensed (sorry no idea on this calculation) the quicker you drink it the less important the exact amounts are. Hopefully someone with some experience can clarify further.

 

[Horners]

I have stout set up and got the regulator wrong through being too impatient. If I recall correctly @LeeH was all over this, had some good insight and I think even a spare tap for sale.

 

[BrewHouse]

Thanks Simon, Yes it is actually a tank of mixed gas I have, not just nitrogen. I know I have to do the using carbing with CO2 but am not sure how to go about the final delivery.

 

[The Baron]

you use it exactly as co2 to dispense but you need to carb with co2 then just dispense using the mixed gas but as I am sure that you know they have a different connection to a co2 bottle I believe one is female and the other male. It will give you a creamier head also lager dispensed using nitrogen will come out like Carling Premier

 

[peebee]

you use it exactly as co2 to dispense but you need to carb with co2 then just dispense using the mixed gas but as I am sure that you know they have a different connection to a co2 bottle I believe one is female and the other male. ...

That'll be right. Nitrogen is very difficult to dissolve in the beer but does make a good "propellant" gas that can avoid over carbonating the beer which would happen if using CO2 at high pressures.

To get Nitrogen to dissolve in appreciable quantities you need to get the temperature of the beer very low and the pressure of the Nitrogen (or "mixed gas") very high (30-35PSI). And you need a tap with a special form of "sparkler" (a "restrictor plate"). These techniques were developed by Guinness to emulate the "traditional" head on draft Guinness. I never understood the love affair of home-brewers with Nitrogen and mixed-gas, especially as most use these gases ineffectively. But you will get a half-decent low carbonation using 25/75 mixed gas at 20-25PSI, but home-brewers can get the same with 5PSI of pure CO2 'cos we won't be pushing the beer very far so are just wasting the Nitrogen component. The "restrictor plate" will still work to get the creamy head from CO2 - if you like that sort of thing (personally I'd rather drink Stout than be prepared for a shave). (EDIT: as @LeeH says in the next post; I may be wrong about 5PSI and restrictor plates as that combination might result in no beer coming out at all!).

But don't believe me (who has already declared his distaste for using Nitrogen in beer); this article makes a descent stab at being educational: http://www.draughtquality.org/wp-content/uploads/2012/01/One-Pager-The-Facts-About-25-75-Gas1.pdf

 

[LeeH]

@peebee has generally nailed it.

The norm here is 70/30, I think 75/25 is a US norm.

If you just serve with CO2 at 5 PSI you won't get that perfect creamy head or cascading pint like you would with cellar gas for 2 reasons IMO.

1 You need high pressure to force the solution through the restrictor plate effectively.
2 Nitrogen is difficult to absorb, but it do get some if you serve at cold enough temps and at high enough pressure as @peebee suggests. This does make a difference.

Due to the above, force carb with the 70/30, not the pure CO2. And also to reduce the chance of over carbonation.

Bland nitro beers taste bland, good nitro beers don't.

I've had a nitro tap for many years so have some practicable knowledge.

I was lucky enough to have the same beer in San Francisco last month at Mikkeller. One on Nitro, one not, side by side in front of me. The difference was night and day between the 2 and was probably the best beer I've ever had. The flavours were smooth and more pronounced with no carbonic acid taste interfering.


Just my 10p, your mileage may vary...

 

[BrewHouse]

Thanks Peebee, You know what it like with this hobby - always tempted by another curiosity! (In fact, any excuse to sneak another bit of kit into the brewhouse). I live in a very hard water area and my stouts are generally very good. Our local village pub was brought back from the brink by the current landlord who has concentrated on food and the beer can sometimes be a bit dodgy. But, hats off to him. If he hadn't done so we would no longer have a village pub. However, many of us have started on the Guinness because it is always reliable and the decent beer can be a bit hit and miss. So, I have 6 or so Guinness drinkers who come here every month and I have always served them ok beer. I have done coffee stouts. I have done chocolate stouts. The last consensus was : all very interesting but can't you do some Guinness?
So, I am giving it a go.

 

[peebee]

The norm here is 70/30, I think 75/25 is a US norm. ...

Just a very minor technical note (and I don't know if this is true or cobblers written by the bunch who have passed it to me): When describing "mixed gas" always put CO2 first, so you get 30/70 and 25/75.

Feel free to correct me, 'cos I don't actually give a monkey's. But to make any correction believable please give an authoritative reference.

(EDIT: And yes, 25/75 would be wrong. It should be 30/70.)

 

[peebee]

Thanks Peebee, You know what it like with this hobby - always tempted by another curiosity! (In fact, any excuse to sneak another bit of kit into the brewhouse). ...

Don't I know it! This week I've just coughed up a four figure sum to have some (curious) Grainfather kit when I've got a perfectly serviceable 75L brewery already. Okay, that's a lie. It's not currently serviceable (bit of trouble with some induced voltages).

At the beginning of the year I tried to emulate the Guinness "high cask, low cask" system, which is what Guinness attempt to emulate with their "Nitro" developments. Guinness were messing with Nitrogen and kegs (and later "widgets") way back in the 1950's. My attempt was a bit of a failure - or it didn't provide any advantage over a single cask setup. But it was serving a stout (actually my take at a 18th century London porter) at only 1-2PSI of CO2 and it had the sort of head some seem to think is only possible with Nitrogen.

(That's from single cask, not the high/low setup, at 2PSI with CO2, no nitrogen! And the blue sticker? Yes it does say "Angram", as in … this was hand-pumped!).