How do i use Co2/nitrogen for carbonation ?

[Jimash]

Hi all,
I am new to this page and hope this post is in the right place.
I am just after some info regarding carbonating with co2(30%)/nitrogen(70%) mix.
I have just finshed fermenting a stout and ready to keg but am unsure of what pressure to prime the keg at and despence at. I have a flow restricter on my beer tap also.
I am hoping to achieve results along the line of the Guinness with the different gas.

 

[Moad]

I'm about to do this too. I've read you want to carb with 5 psi with co2 then hook up on your nitro at 25-30 psi to dispense

 

[danestead]

I use about 25-30psi and let it gas up over time. It does take longer than straight co2 to gas up though I find. I never messed around with quick carbing with nitrogen mix so cannot suggest any quick methods.

 

[Jimash]

With the pressure being around 25-30, are you using a 5mm line to your tap?

 

[rass]

Where do you get your nitrogen from? Do you need a different reg setup? Are there any good (and australian) resources on Nitro?

 

[MHB]

With 70/30 gas mix (N2 is always given first) roughly you will get 30% of the dissolved CO2 at any given pressure/temperature that you would with pure (100%) CO2.
There are a couple of ways to work out the desired pressure -
Needed serving pressure, probably going to be somewhere between 100-200kPa with a stout restrictor tap, just what you need to get the flow at the tap you want.
How much dissolved pressure you need to get the flavour from dissolved CO2 that you want in the beer.

Braukaiser covers the solubility of CO2 pretty well, the link is to the carbonation table for CO2 in g/L and kPa at a given temperature.
Say you decide you want 3g/L of CO2 and your beer is refrigerated at 5oC. Looking at the table you will see that you need just a smidge over 10kPa of CO2
Partial Pressure (reg setting) will be XkPa * 0.3 = 10, PP =10/.03 = 33kPa.
If you are interested you can read up on Daltons Law, but you need absolute pressure so you have to add Atmospheric pressure to Partial Pressure (101.3kPa) so you will need around 134kPa Gauge Pressure.

Just remember that N2 is about 1/100th as soluble as CO2, so it takes a lot longer to dissolve into the beer, I have found 2 weeks as a minimum to reach equilibrium, 4 is better.
Mark

 

[danestead]

With the pressure being around 25-30, are you using a 5mm line to your tap?

I'm pretty sure it's 5mm ID and my lines are about 3m if I remember correctly.

 

[Jimash]

Thanks heaps for the info everyone.

Really looking forward to see the end results, sounds like there is alot more involved compared to co2.


I just purchased a new regulator from Keg King ($60) which is a multi gas reg so it can handle the high cylinder pressures. (My co2 reg dont go high enough. You need to check first.
With the gas, i got it from BOC. I think it was $40 for the gas plus bottle rent. I had to order it in as my nearest store didnt stock the gas but it was in the next day.

 

[Jimash]

Is it also worth going to 4mm lines or stay with the 5mm with the higher pressure?

 

[MHB]

Stay with what ever works for a normal CO2 delivered draught system, the Stout Restrictor (the little plate with pin holes in it) in the tap will create all the extra back pressure you need.
M

 

[Yob]

is there an effect on taste for using Nitro or just that creamy head?

 

[mofox1]

You wouldn't get as much carbonic acid produced with a nitro setup.. it's what, 70/30 n2 to co2? That should affect taste independent of the obvious body/mouth-feel component.

 

[MHB]

Personally I think it guts beer - flavour and aroma wise.
Because N2 has a low solubility and you are applying a high pressure to force it into the beer, it leaves very quickly and strips out a lot of the aromatics on the way.
Given the choice between a Nitro Served beer and a Casked Ale I would go with the cask every time.

I can see the advantages for a commercial brewer, but as an home brewer who has had Nitro Pour on tap - I don't see the point, get a cask!
Mark

 

[Mardoo]

I'd have to agree. I was thinking about nitro for ages, but wondering about flavour. Hand pumped beers have always tasted better to me than Niro-served beers. One nitro supporter said, "Pours just like from a cask." Seemed like a no-brainer. Beer engine is supposed to arrive today, still sorting cask though, but a low-pressured keg will serve in the meantime.

 

[Mardoo]

Thought I heard a knock at the door while I was typing that! Needs a bit more assembly after I finish working. Cost about the same as a nitrogen bottle, including shipping. Utterly stoked!

 

[danestead]

is there an effect on taste for using Nitro or just that creamy head?

Yes I find it definitely changes the flavour, aroma and mouth-feel compared to co2.

 

[Moad]

I'm getting setup with the sole aim of producing a "Nitro" milk stout clone by left hand brewing... incredible beer

 

[Lyrebird_Cycles]

Braukaiser covers the solubility of CO2 pretty well, the link is to the carbonation table for CO2 in g/L and kPa at a given temperature.
Say you decide you want 3g/L of CO2 and your beer is refrigerated at 5oC. Looking at the table you will see that you need just a smidge over 10kPa of CO2
Partial Pressure (reg setting) will be XkPa * 0.3 = 10, PP =10/.03 = 33kPa.
If you are interested you can read up on Daltons Law, but you need absolute pressure so you have to add Atmospheric pressure to Partial Pressure (101.3kPa) so you will need around 134kPa Gauge Pressure.

Mark

You've got that backwards. The table is written in gauge pressures so you have to convert to absolute before you do the partial pressure equivalence.

In the case given, 10 kPa gauge = 111 kPa absolute. Divide by 0.30 for the 70 / 30 mix gives you 370 kPa absolute = 269 kPa gauge.