Issues with Nitro

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ronan

Active Member
Joined
Aug 1, 2012
Messages
35
Reaction score
2
Location
Chicago
This is my first run with Nitro aka beer gas and I'm having mixed results with a Boddy clone. My main issue is too much foam and no head retention. My keezer is set to about 41f and my tap is about 14ft away on a refrigerated long draw system.

My setup is the following.

* C02 tank and Reg filled with beer gas 30 PSI
* Cornelius Keg
* Krome Stout Faucet

I think that I may of over force carbed the beer but uncertain since this is my first attempt. I read is some places that a carb stone on the IN of the keg may help.
 
ronan said:
Force carb'd for a few days on C02 alone the switched to beer gas for pour

What was the pressure and temp during those few days? Did you use a carb stone, or shake the keg, or just let it sit? Exactly how many days was it carbing?
 
I read is some places that a carb stone on the IN of the keg may help.

thats only a cheap fix instead of learning how to properly carbonate your beer. putting the carb stone on the IN port would be the same as carbonating your beer without a stone at all.

when dealing with beergas and 'exotic' gas pressures, temperature and accurate carbonation level is much more critical than your average 2.2vol carbd ales. have some patience and take the time to do it right.
 
Did the shake and roll method for carb'n with the temp of the at about 34 F. I have another batch (Guinness Clone) that will be ready for kegging in a few more weeks and want to do that one properly. I don't have a stone but see no issue with picking one up or should I just toss CO2 on it for a week at low pressure? Or does it even require CO2 if using Beer Gas? I have read that trying to Nitrogenate a beer is a futile effort and just use Nitro for dispensing only.
 
You need a low carbonation if using a nitrogen setup. Carbing normally will result in a lot of foam. Remember you are forcing beer through tiny holes at 30psi. There is going to be some turbulence. Shoot for like 1.5 volumes CO2. Hopefully your beergas is 75% Nitrogen and 25% CO2, or close to it. The nitrogen is there to push the beer through the faucet at a high pressure, without over carbonating the beer. It is also used in draft systems with very long lines (more resistance) that needs a higher pressure to get to the shank, and served through a regular faucet, without overcarbing the beer.
 
Did the shake and roll method for carb'n with the temp of the at about 34 F. I have another batch (Guinness Clone) that will be ready for kegging in a few more weeks and want to do that one properly. I don't have a stone but see no issue with picking one up or should I just toss CO2 on it for a week at low pressure? Or does it even require CO2 if using Beer Gas? I have read that trying to Nitrogenate a beer is a futile effort and just use Nitro for dispensing only.

We really need more info to properly diagnose the problem. What pressure did you use while shaking and rolling it? FWIW shaking and rolling the keg at anything over the pressure that corresponds to the desired carb level often results in overcarbed beer. What blend of beergas are you using for serving, and at what pressure? What carb level were you shooting for.

thats only a cheap fix instead of learning how to properly carbonate your beer. putting the carb stone on the IN port would be the same as carbonating your beer without a stone at all.

:confused: How is using a carb stone not properly carbing your beer? It's just a tool to reduce the time for the set and forget method from 10-14 days down to under 24 hrs. It's also how almost all commercial beer is carbed.
 
Set it to about 20 PSI during the shake and roll, As for the blend it supped to be 75/25 and i'm serving at 30PSI. As for an ideal carb level I'm thinking 1.5-1.8 unless lower is more desirable for an nitro beer?
 
Just for some context here is a pic of a typical pour. The head will take about 8-10 min to dissipate and after it does there is little retention. And whatever is left will be uneven and spotty in bubble composition. Looks more like soap suds.

photo.jpg
 
ronan said:
Set it to about 20 PSI during the shake and roll, As for the blend it supped to be 75/25 and i'm serving at 30PSI. As for an ideal carb level I'm thinking 1.5-1.8 unless lower is more desirable for an nitro beer?

My guess is that it's overcarbed. Doesn't take long to get over 2 vol by shaking and rolling at 20 psi. If you left it at 20 psi for a few days after shaking it, then it's overcarbed for sure. Do you have a cobra faucet or regular faucet you can try just to see what the carb level is like? Is gas building up and forming pockets in the beer line if it sits without being poured for a few hours? Anything under ~2 vol should be fine on nitro, but with the info you've given, you'll probably need a higher serving pressure than 30 psi.
 
I'm going to try and pull some carb off tomorrow by bleeding pressure from the keg and I will try doing a serve pour at above 30 psi perhaps 35. One thing I forgot to mention was that on day one it was working like a champ except I could do one perfect pour with nitro at 30 psi but if I went to serve a second pint immediately after the first it would pour flat with no head. That was my motivation to do an additional force carb. Perhaps I over-shot it on this one.
 
I'm going to try and pull some carb off tomorrow by bleeding pressure from the keg and I will try doing a serve pour at above 30 psi perhaps 35. One thing I forgot to mention was that on day one it was working like a champ except I could do one perfect pour with nitro at 30 psi but if I went to serve a second pint immediately after the first it would pour flat with no head. That was my motivation to do an additional force carb. Perhaps I over-shot it on this one.

The plot thickens. So this beer was already at least partially carbed prior to you putting it on pure CO2 at 20 psi and shaking it, and then leaving it on pure CO2 for several days, possibly still at a high pressure. Now I'm even more convinced that it's way overcarbed. FWIW it only takes 3-5 psi of pure CO2 to reach the carb level range you mentioned. It's likely going to take bleeding the pressure dozens of times over the course of a couple days to get the carb level back down. There is a shortcut though, where you push gas at a low pressure through the liquid out diptube while holding the pressure relief valve open. And 35 psi is likely still too low. With a 75/25 blend gas, 1.6 vol of carbonation, and 41°F serving temp, according to the calculators you'd need somewhere around 55 psi for a truly balanced system. The 30 psi you've been using is about right for a 60/40 gas blend.

http://mcdantim.com/distributor-tools/calculators/
 
ok ran the calc and came up with mixed results. 47 PSI that can't be correct, can it?

Screen Shot 2012-08-21 at 1.40.00 PM.png
 
Yes it can be correct. Since you have just 25% CO2 in the gas mix, you're at 1/4 what you would have with straight CO2. The 47psi will put you at just under 12psi equivalent. You might need to get a longer beer line for that faucet too. I won't say for certain since I've not [yet] set up to serve via a stout tap on beer gas.
 
Finally after a de-carbination and 42 psi of beer gas we have a near perfect pour.

Good deal. Looks tasty too. :mug:

Stout taps because of the restricter plate do not need long beer line for balance

More or less. They usually work best with 10-40 psi at the restrictor plate, so there are some rare instances where changing the line length or diameter can be helpful.

I got the calc from here. It actually suggested 47 PSI on beer gas but at 44 it blew one of the ball locks off the corny. I'm satisfied at 42 might try dropping it by a few LBs just to see if there is a noticeable change in the pour quality.

http://mcdantim.com/distributor-tools/calculators/

The 47 psi the calculator came up with is what will keep perfect equilibrium with your carbonation level. Unlike when using 100% CO2, this isn't all that important when using beer gas. Because of the high pressures and the nitrogen, very little of the CO2 will come out of solution if you use lower than the equilibrium pressure. Even at 35-40 psi the amount of carbonation you'd lose over the course of the keg would be so small that most people couldn't tell the difference.
 
Yes it can be correct. Since you have just 25% CO2 in the gas mix, you're at 1/4 what you would have with straight CO2. The 47psi will put you at just under 12psi equivalent. You might need to get a longer beer line for that faucet too. I won't say for certain since I've not [yet] set up to serve via a stout tap on beer gas.

This is a decent rule of thumb, but it's not exactly 1/4 equivalence... The pressure on a regulator gauge is zeroed at 1 atmosphere, meaning that if your gauge reads 0.1 it is actually already applying 14.8 (1 atmosphere + .1) pounds of pressure. 1/4 of the gas "below" the 0 point in the gauge is also CO2, so you have to account for that in the calculation.

Point being, if you're looking for 2.27 volumes CO2 (12psig at 40º on pure CO2) and serving on beer gas, you're going to end up with less and less dissolved CO2 over the course of the keg. The gas equivalences can be found with these formulas, though:

To find the equivalent pressure for beer gas to give the same CO2 content as pure CO2:
Pbeergas = (Pco2 +14.7) / (% CO2 in Mix) - 14.7

E.g., a mix of 25%CO2/75% N2 would give the same CO2 pressure as 12 psig of pure CO2 at:
= (12+14.7)/(.25) -14.7
= 92.1 psig of beergas
*note: psig = psi of gauge, v. psia = psi absolute
And to find out how much applied pressure the CO2 in a mixed gas is applying on the beer, just reverse it (the 47psi is from your beergas setting):
Papplied = (% CO2 in Mix) * (Pbeergas +14.7) - 14.7
= .25 * (47 + 14.7) - 14.7
= 0.725 psig of CO2​

You'll notice that under the serving pressures for beer gas, 30 to 45 psig works out to -3.525 psig (or 11.18 psia) of CO2 to 0.225 psig (14.92 psia) of applied CO2. At 40º, this works out to 0.83 to 1.18 volumes of CO2. The fact you can have less than one atmosphere of applied CO2 pressure with beer gas is why you can get these low volumes - at the same temperature, 0.1 psig (just barely moving the needle) on a pure CO2 gas will only get you down to 1.17 volumes CO2.


TL/DR version: Set your beer gas to 30-40 psig and you'll end up with between .8 and 1.2 volumes of CO2. Don't expect to get the same dissolved CO2 as a pure gas unless you really pump up the applied pressure, though...
 
So now that I have the perfect blend of carbing with conjunction of pressure I beginning to realize mixed beergas does not give you the milage CO2 does. I going through a 5LB tank in less than one corny. Does this sound right? Basically is its like a 1$ of gas per pint at the moment.
 
ronan said:
So now that I have the perfect blend of carbing with conjunction of pressure I beginning to realize mixed beergas does not give you the milage CO2 does. I going through a 5LB tank in less than one corny. Does this sound right? Basically is its like a 1$ of gas per pint at the moment.

You have a leak somewhere. Submerge everything you can in a bucket/tub/etc. Spray everything else with star-san.
 
Ok one last question. I just legged a really nice irish red ale that I would like to put on nitro in short time. My newer process is carb at 1.5 PSI on co2 for about a week while the beer is at 37ish degrees. I do this before putting on nitro and the results have been decent. I would however like to serve this up for some friends tomorrow any suggestions to get this moving quicker. Can I do the shake and role with beer gas ? As of now it has some minor carbonation and it does pour at high pressure but no cascade or head.

Thanks
 
This is a decent rule of thumb, but it's not exactly 1/4 equivalence... The pressure on a regulator gauge is zeroed at 1 atmosphere, meaning that if your gauge reads 0.1 it is actually already applying 14.8 (1 atmosphere + .1) pounds of pressure. 1/4 of the gas "below" the 0 point in the gauge is also CO2, so you have to account for that in the calculation.

Point being, if you're looking for 2.27 volumes CO2 (12psig at 40º on pure CO2) and serving on beer gas, you're going to end up with less and less dissolved CO2 over the course of the keg. The gas equivalences can be found with these formulas, though:

To find the equivalent pressure for beer gas to give the same CO2 content as pure CO2:
Pbeergas = (Pco2 +14.7) / (% CO2 in Mix) - 14.7

E.g., a mix of 25%CO2/75% N2 would give the same CO2 pressure as 12 psig of pure CO2 at:
= (12+14.7)/(.25) -14.7
= 92.1 psig of beergas
*note: psig = psi of gauge, v. psia = psi absolute
And to find out how much applied pressure the CO2 in a mixed gas is applying on the beer, just reverse it (the 47psi is from your beergas setting):
Papplied = (% CO2 in Mix) * (Pbeergas +14.7) - 14.7
= .25 * (47 + 14.7) - 14.7
= 0.725 psig of CO2​

You'll notice that under the serving pressures for beer gas, 30 to 45 psig works out to -3.525 psig (or 11.18 psia) of CO2 to 0.225 psig (14.92 psia) of applied CO2. At 40º, this works out to 0.83 to 1.18 volumes of CO2. The fact you can have less than one atmosphere of applied CO2 pressure with beer gas is why you can get these low volumes - at the same temperature, 0.1 psig (just barely moving the needle) on a pure CO2 gas will only get you down to 1.17 volumes CO2.


TL/DR version: Set your beer gas to 30-40 psig and you'll end up with between .8 and 1.2 volumes of CO2. Don't expect to get the same dissolved CO2 as a pure gas unless you really pump up the applied pressure, though...

My head hurts.
 
Back
Top