Pure Nitro setup questions for stout

[monkijohnni]

Well, as a followup, the beer turned out pretty awesome. 20 PSI CO2 for two days (cold), and then serving with pure N2 at 20 PSI. Head improved after 48h on N2. Good cascade, good head.

-Creamy IPA on nitro: the stuff of dreams.

 

[Supabrew]

Hi Guys,

I realize this is resurrecting a super ancient thread, but I thought it would make more sense to ask here than start a whole new one... as this is one of the most relevant threads on the web and HBT.

Has anyone who opted to push a carbed beer via straight N2 seen the dreaded reduction in carbonation over time? And if so, what was your method of "topping off" your keg with carbonation?

I know beer gas is more ideal and understand partial pressures and the declining CO2 levels pour after pour, but the lady likes nitro coffee, we push that with pure N2 and I do not have room for a third tank and regulator in the kegerator along with all these 5 and 2.5 gallon kegs

 

[kdog_x]

Thread resurrection again! Supabrew, did you end up trying this? I'll have the answer within a couple months. Brewing a stout next weekend and then going to force carb for 2-3 days and then serve on straight Ar. I figure if it goes flat half way through I will just top it back off on the co2 line again. I already have 2 smallish argon tanks for TIG welding, so buying another cylinder for beer gas doesn't make financial sense. MIG welding gas might be more ideal 75/25 - Ar/CO2, but I only have one MIG tank and it's too big and heavy to want to move it to the keezer location. Usually a keg lasts about 8-10 weeks unless there's a big party so I should have a good idea how well it holds up

 

[Supabrew]

did you end up trying this

Hi @kdog_x I am actually kegging a RIS today. It's a 5 gallon batch, which I will be splitting into two 2.5 gallon kegs, one to tap and one to age in the basement.

I plan to use straight CO2 to about 1.6-1.8 vol then push it with straight Nitro.

As you said, once it starts tasting a little flat, I will vent the Nitro and re-pressurize with CO2.

I don't know much about Ar...does it work similarly to a stout faucet where the Ar pressure is high and you get a nice cascading effect? I know there are a few users on HBT who use Ar to push, though I already have two 5# tanks in my kegerator so a third (whether it be Ar or a blend won't fit!). I'm lucky enough to be able to fit 5 beers/beverages in there!

 

[kdog_x]

From what I understand the cascading effect is mostly from the stout faucet so I would think Argon would also produce that effect. I don't know if the required pressure is going to be the same as nitrogen, but my guess is that it will be pretty similar. Pitched the yeast into the stout last night, so I will be testing this in a couple weeks

 

[masonsjax]

Cascading comes from a small amount of CO2 that is dissolved into the beer being violently agitated out of solution by pushing with high pressure through the restrictor plate in the stout faucet. Nitrogen or argon doesn't dissolve easily into liquid at serving temps, it's just there to push with high pressure. If you used just CO2, it would be way over carbonated at those pressures and temperatures.

 

[Supabrew]

Pitched the yeast into the stout last night, so I will be testing this in a couple weeks

Awesome! I missed my window of opportunity to keg so will be doing it this weekend. I plan to carb, though I am pretty low on Nitro so will have to drop the tank off to get it sent out to be refilled early next week... imagine a whole 5 pound N2 tank to push cold brew coffee for two people... achievement unlocked?

Cascading comes from a small amount of CO2 that is dissolved into the beer being violently agitated out of solution by pushing with high pressure through the restrictor plate

Very cool, what are the differences between PSI for N2 vs Ar? I push with N2 around 45-50 PSI, for coffee anyway, for beer it is TBD as I will go up slowly until I get the desired effect starting around 35-40 PSI.

 

[kdog_x]

Tried this out with coffee and stout, both worked perfectly!! The coffee was served flat, the stout was carbed up on CO2 at 30 PSI @ 34 degrees overnight and then dropped to 7PSI for 2-3 days. Then it was switched over to the argon @ 35 PSI. It takes a few days to get the effect if you use the regular gas port. If you diffuse the gas in through a stone it gets the desired effect in about an hour.

 

[acidrain]

My only input to the 7-1/2 year discussion is that it is impossible for Co2 to come out of solution in the keg while under N2 pressure of at least the equilibrium pressure of the beer.
You never have to go back and re-carbonate the beer.
Typically you carb at normal volumes, which for stouts may be less than ales.
Then serve using high pressure (30 psi-ish) using a stout faucet, which has a restrictor plate that makes it foamy.
The reason you would use beergas, is because it can carb the beer and serve it using one gas.
The reason you would use pure N2 is because it's cheaper than beergas, and as long as you carb with Co2, then serve with Pure N2, it works.

 

[day_trippr]

"it is impossible for Co2 to come out of solution in the keg while under N2 pressure of at least the equilibrium pressure of the beer."

Pretty sure the partial pressure gas laws say this is incorrect, but I'm not too old to be re-educated

Cheers!

 

[dcross1796]

Resurrection again of this little thread that won’t die!

I am building a new keezer and would like to add a stout faucet for nitro brew coffee and beer. Coffee requires pure nitrogen. This thread gives conflicting results of how beer would do being served with pure nitrogen.

A main issue discussed in the thread is that beer will lose carbonation over time. I think I have a solution. What if I used a carbonation lid with a carbonation stone. Doing this will make the keg have three posts. So when I have a beer to serve with pure nitro I leave the keg hooked up to Co2 at the same time on one of the three posts.
Does this sound like it would work?

 

[dcross1796]

"it is impossible for Co2 to come out of solution in the keg while under N2 pressure of at least the equilibrium pressure of the beer."

Pretty sure the partial pressure gas laws say this is incorrect, but I'm not too old to be re-educated

Cheers!

You seem knowledgeable on this subject. Can you please answer the question I just posted to this thread?

 

[Transamguy77]

Resurrection again of this little thread that won’t die!

I am building a new keezer and would like to add a stout faucet for nitro brew coffee and beer. Coffee requires pure nitrogen. This thread gives conflicting results of how beer would do being served with pure nitrogen.

A main issue discusses is that beer will lose carbonation over time. I think I have a solution. What if I used a carbonation lid with the carb stone on a keg. Doing this will make the keg have three posts. So when I have a beer to serve with pure nitro I leave the keg hooked up to Co2 at the same time on one of the three posts.
Does this sound like it would work?

Your idea will work to a degree, the nitro pressure is way higher than the Co2 pressure, so you might be able to keep the Co2 hooked up and set to like 10lbs until you use the nitro, then you can disconnect the Co2 and serve with the nitro, degas the keg and hook your Co2 back up.

 

[day_trippr]

Ok, some difficult to parse verbiage but I think I get the gist.

- If dispensing coffee, only nitrogen is used, and the 2nd keg input would go unused.
- If dispensing stout, both keg inputs are used, the CO2 pressure would be set to achieve and maintain the desired carbonation level while the nitrogen would provide the push.

Obviously the mixed gas mode is more interesting, but if the respective gauge pressures are set correctly I believe this should work.
One thing to keep in mind when driving beer through a stout faucet: you want the carbonation level to be quite modest - like in the 1.2-1.4 volume range...

Cheers!

 

[Vale71]

Does this sound like it would work?

Nope. Regulators work on absolute pressure. This means that if you have one reg set to a lower pressure than the other only the reg with the higher setting will actually push gas into the keg. So in this case you'll have the CO2 regulator set to a lower pressure than the N2 regulator, the CO2 reg will do nothing and you'll be actually serving with pure N2 all the time.

 

[day_trippr]

As much as I wish there was a gas law to bail out on I believe that is right and it won't work. Pity...

Cheers!

 

[dcross1796]

Thank you all. I apologize for the horrible grammar in my post.

 

[dcross1796]

Nope. Regulators work on absolute pressure. This means that if you have one reg set to a lower pressure than the other only the reg with the higher setting will actually push gas into the keg. So in this case you'll have the CO2 regulator set to a lower pressure than the N2 regulator, the CO2 reg will do nothing and you'll be actually serving with pure N2 all the time.

This makes sense. Thank you. So if I were to take my idea and go with the same setup would it make sense to just turn the N2 off when not serving and purge the keg? That way the co2 levels are maintained and the N2 can be used for both coffee and stout applications?

 

[dcross1796]

This makes sense. Thank you. So if I were to take my idea and go with the same setup would it make sense to just turn the N2 off when not serving and purge the keg? That way the co2 levels are maintained and the N2 can be used for both coffee and stout applications?

@Transamguy77 addressed this already, thank you.

 

[SBH2021]

I think it would depnd on how frquently you dispense from this keg how quickly the co2 would come out of solution. The bump every 3 weeks may be fine if you only draw a few beers a week. I am sure there are some physicists on here that could calculate the math for you, however if you dispense too many beers without recharging the co2 your beer will go flat.

I agree beergas tanks suck, refill here is $44.00. I really like my stouts and I want them on a nitro mix so I invested in a gas blender to make my own beer gas in real time. This setup is probably cost prohibitive for most, but I now pay half as much for a full n2 tank and a full co2 tank combined, and it lasts 4 times as long.

I am in the same situation and here to, in Quebec, Canada, the gaz companies do everything they can to get you to rent their bottles which end up costing twice as much as if you can get your own bottles refilled end recertified every 5 years. I just got a new N2 tank and was planning to CO2 my stout and then push it with N2 but from what I can read it is not best I guess. What do you use to blend your gases?

 

[Broken Crow]

Have you asked your local bars and restaurants who thier supplier is? ...blenders are very costly, but I know that Praxair (an eternal 'rent our tanks") sells them.