Pure Nitro setup questions for stout

[CidahMastah]

Was hoping that some people could help me out with clearing up some details about what equipment is needed to go from a beergas mix to a pure Nitrogen mix.

After using a size 23cu beergas mix to carb and push about 2 corny's I noticed the tank is about kicked. Way too soon for a $30 fill. Based on the above I decided that I either need to always precarb my stouts with CO2 and THEN add them to beergas.... OR precarb with CO2 and put them on pure Nitrogen.

I have a couple questions.

1. Is the gas I am looking for "N2"? Is this liquid Nitrogen ion the can that gets converted to a gas as it warms and exits?
2. Will my current tank and regulator still be able to handle the pure Nitrogen? i.e. do I need a special tank to hold pure Nitrogen?

Any tips or personal experience with this set up is appreciated. I really love the results I have gotten so far on a cream stout and a guinness clone, but the cost needs to improve for me to be truly happy.... though I would probably still keep using the system as is even if I couldn'
t improve the cost....

 

[CidahMastah]

ok, so I got some answers from my local gas supplier - made the trip to figure it out.

1. Is the gas I am looking for "N2"? Is this liquid Nitrogen ion the can that gets converted to a gas as it warms and exits?
A: Yes, in the gas state, not liquid. It would last slightly longer than the beergas mix, but since it is in a gas state you still get less gas vs. a co2 tank.

2. Will my current tank and regulator still be able to handle the pure Nitrogen? i.e. do I need a special tank to hold pure Nitrogen?
A:Yes, as long as it is Nitrogen in the gas state. No special tank needed for Nitrogen in a gas state.

 

[Brewerforlife]

Why 100% N2? What will maintain the carbonation level in the beer keg with100% Nitro?? That's, unless you plan on drinking it all right away, before all the CO2 comes out of solution!!

 

[CidahMastah]

Why 100% N2? What will maintain the carbonation level in the beer keg with100% Nitro?? That's, unless you plan on drinking it all right away, before all the CO2 comes out of solution!!

Well I was naive to the fact that N2 would be in a gas state. I had thought that perhaps you could get pure N2 in a liquid state and push with it from the tank in a liquid state to a gas state like you do with CO2 (i.e. more life out of the tank with liquid state than gas state). But as I found out, they package the N2 in a gas state, just like they do for the beer gas mix. So you won't get a ton of benefit from using it without the mix.

My original plan was as you mention. carb it on co2, push with N2 until the carb was falling out and then blast with CO2 to get the carb back as needed (a couple threads on here suggested 3+ weeks without loss of carb). Turns out there probably isn't a really big advantage to going pure N2, unless you have a gas mixer $$$.

 

[audger]

it takes something like 5000+ PSI to contain nitrogen in liquid form at room temperature, which is why all liquid nitrogen is stored cold at low pressure as opposed to compressed at high temperature.

what was the idea behind using pure N2 and having to constantly recarbonate your beer, instead of just using beergas? putting 100% nitrogen ontop of your beer would functionally be the same as leaving zero psi of CO2 on it.

so once the keg was carb'd it would stay that way untill you started to drink it. the CO2 would equilize into the increasing headspace of the keg and you would loose carbonation faster and faster as the volume of headspace increased. it wont escape back upstream into the N2 bottle, but you would loose carbonation at the same rate as you would if you dispensed the keg without hooking it up to any gas. it would be fine if you drank the whole thing in a day or two, but over a few days/weeks/or longer...

you would have to charge it with CO2 more frequently as the keg emptied.

 

[CidahMastah]

what was the idea behind using pure N2 and having to constantly recarbonate your beer, instead of just using beergas? putting 100% nitrogen ontop of your beer would functionally be the same as leaving zero psi of CO2 on it.

My original plan was as you mention. carb it on co2, push with N2 until the carb was falling out and then blast with CO2 to get the carb back as needed (a couple threads on here suggested 3+ weeks without loss of carb).

as per the above you wouldn't have to constantly recharge with co2, maybe give it a boost once or so every 3 weeks ish.

so once the keg was carb'd it would stay that way untill you started to drink it. the CO2 would equilize into the increasing headspace of the keg and you would loose carbonation faster and faster as the volume of headspace increased. it wont escape back upstream into the N2 bottle, but you would loose carbonation at the same rate as you would if you dispensed the keg without hooking it up to any gas. it would be fine if you drank the whole thing in a day or two, but over a few days/weeks/or longer...

see my previous above bolded response.

Do you have personal evidence/experience that the last sentence (you have written above) in particular is true? People on HBT are reporting contrary to what you are saying, indicating they did not have to bump the gas for 3weeks or more at a time.


There are at least two people I have read that push their nitro setups with pure gas. Yurirage pushes his with pure argon and another guy, can't recall his screen name pushes with pure N2. I assume that there may be a cost advantage or similar, other wise why not use beergas. But the fact remains that these two gents do this and have had success (maintaining carb for over 3 weeks) contrary to what you seem to imply; that the carb would fall out in days.

 

[zazbnf]

Do you have personal evidence/experience that the last sentence (you have written above) in particular is true? People on HBT are reporting contrary to what you are saying, indicating they did not have to bump the gas for 3weeks or more at a time.


There are at least two people I have read that push their nitro setups with pure gas. Yurirage pushes his with pure argon and another guy, can't recall his screen name pushes with pure N2. I assume that there may be a cost advantage or similar, other wise why not use beergas. But the fact remains that these two gents do this and have had success (maintaining carb for over 3 weeks) contrary to what you seem to imply; that the carb would fall out in days.

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.

 

[audger]

Do you have personal evidence/experience that the last sentence (you have written above) in particular is true?

just an intimate knowledge of gas properties. the rate that CO2 would come out of soloution would be highly dependant on several factors; temperature, rate of consumption, frequency of consumption, overall legnth of time it takes to empty the keg, the amount of headspace availble for the CO2 to fill.

this is the main point i was trying to make...

you would loose carbonation at the same rate as you would if you dispensed the keg without hooking it up to any gas.

if you had 1 gallon of carbonated beer, and 4 gallons of empty (nitrogen filled) space, the beer would outgas CO2 into that 4 gallons of space untill it reached an equilibrium pressure. when hooked up to nitrogen at any pressure, the partial pressure of CO2 is zero. the nitrogen will provide the pressure to push the beer out of the keg, but it will do nothing to hold the CO2 in soloution. if there isnt any headspace, not much will come out. as the keg empties, the rate of CO2 loss will increase. because it takes time for the CO2 to come out of soloution, if you finished the last 1/2 of your keg quickly, you may not even notice a drop in carbonation. if the last gallon or two sat around for even a week, you would definately notice it.

a couple threads on here suggested 3+ weeks without loss of carb

depending on your specific drinking habbits and how full the keg is, it could be even longer, or it could be much shorter. you also have to take everything you read on the internet with a grain of salt. most likely these were guesstimates at best and no one actually measured quantitatively how fast the beer was becoming uncarbonated. then theres the "it was this big, i swear" effect. 18 days turns into "3 weeks", turns into...
people naturally have a tendency to minimize or maximize estiamtes to make a story more exciting. you cant take something like that and say "the beer will definately last 3+ weeks without CO2".

i cant make any suggestions as to how long it might take for the CO2 to come out. it will definately depend on your specific scenario, and the many variables above.

 

[dowhatitdo]

I'm confused. All this seems to be talking about dispensing with nitrogen. Will beer not absorb nitrogen to carbonate? Is nitrogen only used for dispensing pressure?

 

[CidahMastah]

I'm confused. All this seems to be talking about dispensing with nitrogen. Will beer not absorb nitrogen to carbonate? Is nitrogen only used for dispensing pressure?

It is commonly said that Nitrogen doesn't get absorbed into beer and is only used to push the brew. However there is something going on that changes the foam and thus the flavor of the brew. For example I brewed a Guinness Clone, served it on low Co2 only, then through a creamer faucet, and then through a nitro tap on co2 and a nitro tap on mix 90 (75/25 N2/Co2 mix). The beers on Co2 taste totally different than the beers on N2. Additionally, the beer cascading improved over the next several days, suggesting the N2 was possibly going into solution on a very small scheme, or it was interacting with the c02, who knows. Bottom line is the head is different, there is cascading, etc. N2 does Something to the beer when it is served.

Since auger says he has an intimate knowledge of gas perhaps he can help out here with what is going on.

The point of this thread was to determine if there was a cheaper/better way to serve the brew using pure N2 versus the beer mix 90 which is pretty expensive. Several HBTers are in fact serving their stouts with pure N2 or Ar gas after they carb them lightly to 1.2-2volumes of CO2. Many of them reporting good carbonation after 3 weeks+ of serving. While CO2 will go out of the brew over time as you serve it, it does take some time and I would guess that what they are reporting is pretty accurate. If you recall it takes a good 2-3 weeks to carb a beer on the set and forget methodf, so it stands to reason it would take about that time to uncarb.

In short, N2 can go into solution, but it only does so with very cold beer and high pressures. So it is not something a home brewer would get any noticeable carbonation from because we are not exerting the kind of temps and pressures needed to do so.

 

[dowhatitdo]

Thanks, that clears a lot up. I just acquired a nitro tank and regulator, ill play around with it. Just got to be careful on pressures. How much pressure does it take to bust pressure relief valve on pin lock keg?

 

[InLimbo]

Just wanting to look at this from a different angle. You want to buy a whole new regulator (optional evidently, but i thought N2 needed a different regulator), storage tank, gas, lines, just to use for dispensing--in addition to your CO2 tank for carbing. So, a pretty substantial upfront cost, increased maintenance, increased junk sitting around because maybe dispensing with N2 will last a bit longer? This also means that both tanks probably won't run out at the same time, so twice the trips to get them refilled etc.. this just seems like it's over complicating things. But that's just my opinion, now onto something else:

You said a single $30 CO2 fill was only enough to carb and dispense 2 corny kegs? How big is this CO2 tank? I honestly have a hard time believing that you went through an entire CO2 tank that fast and have no leaks anywhere. If everyone was going through gas at this rate, no one would be using them. I'm in the process of building my kegorator, but my buddy's has 3 times as many kegs and taps as you, and gets a **** load more life than you do.

 

[CidahMastah]

Just wanting to look at this from a different angle. You want to buy a whole new regulator (optional evidently, but i thought N2 needed a different regulator), storage tank, gas, lines, just to use for dispensing--in addition to your CO2 tank for carbing. So, a pretty substantial upfront cost, increased maintenance, increased junk sitting around because maybe dispensing with N2 will last a bit longer? This also means that both tanks probably won't run out at the same time, so twice the trips to get them refilled etc.. this just seems like it's over complicating things. But that's just my opinion, now onto something else:

you don't have a full understanding of the two set ups and their differences

You need a separate regulator for Nitro (or at least a CO2 regulator with the N2 adapter). These are two separate kegging systems, though I have heard of some people who go all nitro for dispensing.

I am not looking to dispense with N2 over CO2. I was looking at dispensing with N2 (cheaper) over Mix 90 (75N2/25CO2) on the nitro kegging system. I was looking at doing that by precarbing the stout on the co2 sytem then putting the keg on pure N2 to dispense (on the Nitro system). You can't pour a nitro stout without a nitro set up, including the tap. I have 5 taps, 4 on co2 and 1 on nitro; two kegging systems, one co2 and one Nitro (currently using the mix 90).

There is additional needed hardware, but not sure what maintenance you refer to. For me once the gas side is set up you don't need to touch it. You only need to clean the beer lines periodically, but that is the same for any tap line you set up.

You said a single $30 CO2 fill was only enough to carb and dispense 2 corny kegs? How big is this CO2 tank? I honestly have a hard time believing that you went through an entire CO2 tank that fast and have no leaks anywhere. If everyone was going through gas at this rate, no one would be using them. I'm in the process of building my kegorator, but my buddy's has 3 times as many kegs and taps as you, and gets a **** load more life than you do.

You are confused here... I said a single 23cu ft Mix 90 tank was near empty after using it to carb and dispenses two cornies. Not co2. the Co2 setup I have had for over a year and that system I understand (20lb cO2 tank). I recently added the nitro system, which i am learning.

So your friend has over 15 taps? and 60 kegs?

 

[BrewerBaj]

Bump... How did the pure nitro work out. Just accidentally filled mine with pure nitro instead of the mix. Rookie mistake. They may let me trade it back at no cost but if the pure nitro was ok then I may give it a go.

 

[drkatz43]

So now that you've presumably tested/changed things, how'd it go? Any tips or lessons learned that would add to this discussion?

 

[masonsjax]

Since this is a 5 yr old discussion and the OP hasn't been active here since 2013, I'd say go ahead and try it and see how it goes.

From personal experience though, it's very easy to overcarb for a nitro faucet and not enough carb wont give you the cascade and creamy head. It's a delicate balance that I don't trust to alternate carbonation routines. I prefer beergas blend and a set it and forget it regiment. My solution to the tanks emptying quickly problem was an 80cuft tank (not expensive from scott). It lasts a long time and exchanges are less than $30.

 

[Justintoxicated]

Just last night my friend who works at a brewery suggested I go full nitro at home. I may try that and then double the nitro tank usage by making a cold brewed coffee. Otherwise I'd need a 3rd kind of tank!

 

[drgonzo2k2]

Interesting this thread would pop up on my radar today, as I'm in the midst of updgrading our keg setup at work to add both cold brew and nitro coffee taps.

Currently we have two taps on a beer gas system (75%/25% blend). One is at 30 PSI and used for serving nitro stouts. The other is at 5 PSI and used to dispense wine in a keg.

Was investigating the cold brew setup, and we decided to add 2 more taps, pretty similar to how we have the stouts/coffee. One we'll do at 40 PSI for the nitro coffee and the other at 5 PSI for the cold brew.

From chatting with our installation tech he suggested that we ditch the 28CUFT tanks we've been filling with beer gas and go with a single 40CUFT pure nitro tank to power all 4 taps.

I asked about not having the CO2 on the nitro stout, and he said it doesn't really matter as the commercial kegs are properly carbonated from the brewer, and that he's done several installs like this with no problem, so we went with it, and the equipment is en route to set everything up.

Anyone see any problems with this setup? We usually go through nitro beer kegs in 2-3 weeks tops.

 

[day_trippr]

[...]
From chatting with our installation tech he suggested that we ditch the 28CUFT tanks we've been filling with beer gas and go with a single 40CUFT pure nitro tank to power all 4 taps.

I asked about not having the CO2 on the nitro stout, and he said it doesn't really matter as the commercial kegs are properly carbonated from the brewer, and that he's done several installs like this with no problem, so we went with it, and the equipment is en route to set everything up.

Anyone see any problems with this setup? We usually go through nitro beer kegs in 2-3 weeks tops.

Here's the potential problem: as the keg empties and the head space increases, more CO2 will come out of solution to keep the CO2 partial pressure in equilibrium, so the beer will flatten a little more with every pour.
The nitrogen pressure has no bearing on this - which is why beer gas exists.

Frankly, I'd find another tech, because this is pretty basic stuff...

Cheers!

 

[CidahMastah]

I ended up getting a larger beergas mix tank. It sucked paying for initially but it all was ok in the end.

Additionally i usually toss in a couple oz of sugar in to carb my 10g kegs for a couple weeks prior to hook up. Then i wait

 

[augiedoggy]

Was hoping that some people could help me out with clearing up some details about what equipment is needed to go from a beergas mix to a pure Nitrogen mix.

After using a size 23cu beergas mix to carb and push about 2 corny's I noticed the tank is about kicked. Way too soon for a $30 fill. Based on the above I decided that I either need to always precarb my stouts with CO2 and THEN add them to beergas.... OR precarb with CO2 and put them on pure Nitrogen.

I have a couple questions.

1. Is the gas I am looking for "N2"? Is this liquid Nitrogen ion the can that gets converted to a gas as it warms and exits?
2. Will my current tank and regulator still be able to handle the pure Nitrogen? i.e. do I need a special tank to hold pure Nitrogen?

Any tips or personal experience with this set up is appreciated. I really love the results I have gotten so far on a cream stout and a guinness clone, but the cost needs to improve for me to be truly happy.... though I would probably still keep using the system as is even if I couldn'
t improve the cost....

Id try somewhere else if you have options... 23cu of beergas cost be $20 to fill just last week.

I just realized this thread is ancient so the OP was REALLY overpaying 5 years ago.

 

[Justintoxicated]

Interesting this thread would pop up on my radar today, as I'm in the midst of updgrading our keg setup at work to add both cold brew and nitro coffee taps.

Currently we have two taps on a beer gas system (75%/25% blend). One is at 30 PSI and used for serving nitro stouts. The other is at 5 PSI and used to dispense wine in a keg.

Was investigating the cold brew setup, and we decided to add 2 more taps, pretty similar to how we have the stouts/coffee. One we'll do at 40 PSI for the nitro coffee and the other at 5 PSI for the cold brew.

From chatting with our installation tech he suggested that we ditch the 28CUFT tanks we've been filling with beer gas and go with a single 40CUFT pure nitro tank to power all 4 taps.

I asked about not having the CO2 on the nitro stout, and he said it doesn't really matter as the commercial kegs are properly carbonated from the brewer, and that he's done several installs like this with no problem, so we went with it, and the equipment is en route to set everything up.

Anyone see any problems with this setup? We usually go through nitro beer kegs in 2-3 weeks tops.

I have gotten conflicting information even from professional brewers.

I think beer gas is the way to go for stouts without buying an expensive mixing device. (Cheaper and simpler to buy 2 tanks).

However because I also don't want to buy 2 tanks I'm going to carbonate a stout (lower PSI than usual) then put it on nitro and see how it goes. Since the restrictor plate essentially knocks out a bunch of the CO2 anyways I think it can work, especially if you dispense at 40 PSI. Then theres the fact I will only have 1 stout tap, so it will be stout or coffee I guess, maybe I can just switch gases. Or lese buy another stout tap.

I feel I will be drinking more cold brew nitro coffee than stout, so it makes more sense to get the all nitro tank fill and see what it can do. If it does not work out for the stout, I'll just purge it and put it back on CO2. Then invest in another tank for mixing and add a 3rd and 4th port into my chest freezer lol.

The local gas supplier place said they can sell me a steel 60cuft nitrogen tank for $144 and it will come filled. Then even said I can give them one of my 5lb CO2 tanks (I no longer need it as I have 3) to help reduce the cost.

I think I will swing by beverage factory (they are local) and pickup the stout tap and regulator too.

 

[drgonzo2k2]

I have gotten conflicting information even from professional brewers.

I think beer gas is the way to go for stouts without buying an expensive mixing device. (Cheaper and simpler to buy 2 tanks).

However because I also don't want to buy 2 tanks I'm going to carbonate a stout (lower PSI than usual) then put it on nitro and see how it goes. Since the restrictor plate essentially knocks out a bunch of the CO2 anyways I think it can work, especially if you dispense at 40 PSI. Then theres the fact I will only have 1 stout tap, so it will be stout or coffee I guess, maybe I can just switch gases. Or lese buy another stout tap.

I feel I will be drinking more cold brew nitro coffee than stout, so it makes more sense to get the all nitro tank fill and see what it can do. If it does not work out for the stout, I'll just purge it and put it back on CO2. Then invest in another tank for mixing and add a 3rd and 4th port into my chest freezer lol.

The local gas supplier place said they can sell me a steel 60cuft nitrogen tank for $144 and it will come filled. Then even said I can give them one of my 5lb CO2 tanks (I no longer need it as I have 3) to help reduce the cost.

I think I will swing by beverage factory (they are local) and pickup the stout tap and regulator too.

Thanks for your input! After much debate I too decided I'm going to take the try it and see what happens approach.

Definitely not doubting anyone here that's saying the stout will slowly decarbonate. For me though, as this is all a setup I maintain in my spare time at work, it's really more about convenience for me than ensuring a 100% proper pour every time (and no dig on my co-workers, but I'm skeptical that anyone is going to complain).

For beer gas I have to make two trips out of the office during business hours - one to drop off the tank and another the next day to pick it up. For pure nitro and CO2 I have a vendor that delivers and will bring the tanks to me for exchange.

I'd considered going with a gas blender, but in the end that's just too much effort for a work setup. If I were doing this at home (which I'm kind of considering now) I would probably go with a nitro tank, a CO2 tank, and a gas blender.

 

[Justintoxicated]

Stopped by duckfoot brewing for a pour off their nitro taps. A worker there suggested I skip carbonating with cO2 and go for straight nitro at 40psi. Perfect if it works because that's the same pressure for nitro coffee!

Picked up a 60cuft nitro tank, regulator and stainless taprite stout tap. Going Octoberfest camping now, but hoping to make the nitro coffee next week. Stout is going to have to wait a bit as my next brew is going towards a sour barrel project.

 

[CidahMastah]

Let us know how it works at 40 psi n2. Right now i get good cascading w a co2precarb and beer gas mix after. But love simplicity.

At the brewery they might be placing on n2 before the stout degasses after ferment. I.e. this may be why they can get away w pure n2.

 

[monkijohnni]

I'd like to hear an update on your pure N2 dispensing.

I'm about to switch an IPA to pure N2 after it carbonated on pure CO2 for a two days. This is my first whack at nitro, so I'm not sure the right PSIs. I'm carbonating at 20 PSI (CO2 obviously), and plan to dispense at 40 PSI (N2).

Any recommendations? What has worked for others?

 

[drgonzo2k2]

My setup at work has been going for about a couple of months, and no one has complained, and I've not noticed any thing with the couple of pours of nitro stouts that I've had. We've gone through 3 nitro stout kegs in that time. These are commercial kegs properly setup for dispensing on beer gas system. I serve both my nitro cold brew coffee and nitro stouts with pure nitro @40 PSI.

Unfortunately I can't advise you on carbing homebrew kegs for nitro dispensing as I've never done that.

 

[day_trippr]

I'd like to hear an update on your pure N2 dispensing.

I'm about to switch an IPA to pure N2 after it carbonated on pure CO2 for a two days. This is my first whack at nitro, so I'm not sure the right PSIs. I'm carbonating at 20 PSI (CO2 obviously), and plan to dispense at 40 PSI (N2).

Any recommendations? What has worked for others?

You didn't mention the temperature of the beer that you are carbonating at 20 psi, but if it's "cold", and you let it run its course, I predict one hella bad experience at the faucet.

I run my stouts on 35psi 75/25 N2/CO2 gas mix through the war club Micromatic stout faucet. Those stouts are carbed to 1.4 volumes max. Once, as an experiment I tried running a DIPA carbed to 2.5 volumes on the same nitro faucet and the result was about as ugly as pours get

So...bottom line, carb low, serve high.

And I would re-read the entire thread, because it's hard to understand how anyone would conclude that a straight Nitrogen tapline makes sense...

Cheers!

 

[masonsjax]

I advise the same process as straight co2 beers: set it and forget it. For nitro (75/25 blend), I put it on at ~32-35 psi and leave it be. It's just too easy to screw up otherwise. After 2-3 weeks it will cascade as expected. Totally worth the wait.

 

[monkijohnni]

My setup at work has been going for about a couple of months, and no one has complained, and I've not noticed any thing with the couple of pours of nitro stouts that I've had. We've gone through 3 nitro stout kegs in that time. These are commercial kegs properly setup for dispensing on beer gas system. I serve both my nitro cold brew coffee and nitro stouts with pure nitro @40 PSI.

Unfortunately I can't advise you on carbing homebrew kegs for nitro dispensing as I've never done that.

Thanks drgonzo2k2. I just moved my brew to nitro and I think I'll bump up the pressure. I have a nice carbonation at this point from two days on CO2, and the head was nice and creamy. However, I didn't get that good cascade yet. Maybe that will come after more time on nitro or higher pressure.

Anyone have experience with a good pure CO2 carbonating protocol when serving on pure N2?

 

[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!