What's the diff between CO2 and beer gas?

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.

Rbeckett

Well-Known Member
Joined
Dec 23, 2011
Messages
993
Reaction score
72
Location
Bronson
What is the major difference between using straight CO2 or using the beer gas mix? Can you taste any difference, is it more stable or stay in solution longer? The reason I am asking is because beer gas is a specialty gas at my supplier and is much more expensive and I am trying to understand what the benefit of using it versus pure CO2 is. I am not opposed to spendin the extra money if the return is decent, but if the taste or stability is unchanged then I have a tough time justifying the extra expense of mixing the gases. My local supplier is a welding supply facility and can mix it in any proportion I choose, but the mixing fee, plus the hazmat fee in addition to the gas fee starts to become a bit more expensive. Plain CO2 cost me 17 bucks for a 5 pounder, the mix will cost almost double. So is their that much benefit in using mixed gas for a propelant? TIA for your opinions.
Wheelchair Bob
 
From the Micromatic website:

Risk of using Mixed Gas Cylinders

Mixed gas in a cylinder with a ratio of 25% CO2 / 75% N2 is appropriate for stout beers but when applied to ales and lagers, allows the beer to go flat because the partial pressure of CO2 is too low.

Gas suppliers have difficulties raising the ratio of CO2 in the mix as this gas eventually liquefies under high pressure in the cylinder.

This mix in a cylinder is expensive, and the ratios of CO2 and Nitrogen can be very inconsistent and the amount of gas contained in the cylinder is low.

The internal pressure of mixed gas cylinders is also considerably higher than a cylinder containing only CO2, thus increasing the potential risk of an accident.
 
Mixed gas in a cylinder with a ratio of 25% CO2 / 75% N2 is appropriate for stout beers but when applied to ales and lagers, allows the beer to go flat because the partial pressure of CO2 is too low.

This is an oddly worded statement. Ales and lagers, guess stout isn't an ale, go flat with beergas, but for stout it's "appropriate" somehow. The stout is going to go just as flat as the "ales and lagers" are. I understand that they are trying to say it can be style appropriate, but it just sounds weird how they put it.
 
Nitrogen doesn't dissolve into solution as easily as CO2 does. This physical characteristic allows "nitro beers" to be served at high pressure through specialized faucets containing restrictor plates. This pressure/plate interaction creates the cascading creamy head enjoyed with many a beer, not least of which is draught Guinness. Beer gas is unnecessary unless you own a $100 nitro faucet and want to serve beer through it.
 
This is an oddly worded statement. Ales and lagers, guess stout isn't an ale, go flat with beergas, but for stout it's "appropriate" somehow. The stout is going to go just as flat as the "ales and lagers" are. I understand that they are trying to say it can be style appropriate, but it just sounds weird how they put it.

That's true. Maybe Micromatic is just trying to sell their beer system that allows nitro tanks and co2 tanks to be mixed instead of providing accurate information.
 
beer gas has to go into a nitrogen tank and be used with a nitrogen regulator from what the gas distributors told me, reason why they are at a higher pressure than co2, 2200 psi co2 is only rated to 1800 psi, and have to have a stout faucet
 
Nitrogen doesn't dissolve into solution as easily as CO2 does. This physical characteristic allows "nitro beers" to be served at high pressure through specialized faucets containing restrictor plates. This pressure/plate interaction creates the cascading creamy head enjoyed with many a beer, not least of which is draught Guinness. Beer gas is unnecessary unless you own a $100 nitro faucet and want to serve beer through it.

The other time beer gas is used is for really long runs, where the line resistance would be greater than the serving pressure. Not really common amongst homebrewers, but used a lot in long draw set-ups in bars and restaurants.
 
Same idea though: gas doesn't dissolve well and you can serve beer with it under high pressure. That high pressure either forces beer through special faucets or through long runs of tubing.
 
Thank you for all of the very informative replies and interesting logic. I used to mix diving gas (Nitrox) and it was a PITA to hit the numbers dead on most of the time. Usually I was within 1%, but it was time consuming and required a lot of attention to keep from having mix issues later on. Thank God for a gas sampler to insure I had done the math right... And dive cylinders are generally somewhere around 2900 PSI when filled so an accident could be a potential life threatening event in any number of ways....

Wheelchair Bob
 
I am told that many commercial beer pubs such as world of beer, use beer mix for ALL their products, and that when they switched to this, that their sales increased, presumably because of improved flavor?
I've no idea.
I have experimented with doing the same thing at home. I must use regular CO2 to carbonate the beer, because with a lower partial pressure of CO2 in the mixed gas, it takes forever to get it force carbonated. I did notice that toward the end of the keg, that I've had on the mix so far, that the non-stout, with lower pressure applied, that lost some carbonation compared to fresh keg (these are commerical kegs I'm talking about).
The Guinness keg was just fine however, think I had it at 32 psi.
I am now thinking that I should go BACK to serving my beer with CO2, and just dispense the Nitro beers with mix, such as stouts.
It might be that at the large beer pubs like WOB, that their sales and consumption rates are so much higher than at home, that the kegs are empty long before there is a noticeable loss of carbonation for the lower pressure dispense beer. I'd bet if you ran ALL your beer at high pressure, like a nitro/guinness beer, and poured them all through the restrictor stout faucet, that they'd have preserved carbonation levels because the partial pressure of CO2 would be correct, or at least closer to what it should be.

TD

Oh, and yes the mixed gas cylinders are more expensive to refill. I can usually finagle a freebie CO2 exchange on the other hand, so another reason to go back to CO2.
 
Bars use beergas so that they can apply enough pressure to rapidly (by our standards) push beer from basement cold storage up to a bar on a 1st or 2nd floor. If they applied all that pressure with CO2, the beer would be overcarbonated. Some people claim that this changes the flavor (and frown upon the practice) but I don't see how that's possible. The nitrogen is just to push the beer.
 
I used nitrogen once with a keg of Heineken I got for free from a closed restaurant. What a mess. all foam no beer. You had to let the beer sit for a few minutes and add more until you could get a glass full. We switched to c02 and problem was solved.
 
If you don't keep some CO2 pressure on the beer, CO2 will break out of solution to try and re-equilibrate the system. This means you'll get foam.
 
Beer gas is sold in many different Blend%. Stout gas is usually25/75%. But beer gas has higher CO2% in the blend, like 60%CO2/40%N2 or 70%CO2/30%N2. It is used for pushing beer when the resistance is greater than the 17psi you can get away with using straight CO2, without over-carbing the beer.
Most long draw draft systems are set-up with a gas blender and usually set-up with around 22 psi of resistance in the lines, and run with a gas blend % of around 60%/40%.
Micro-matic's blenders have pre-set balance percentages, but with McDantim blenders, you can adjust the blend% to whatever you want. This way you have to buy a straight CO2 bottle & a straight N2 bottle, plus the blender, and the high pressure regulator hoses. I Know!! Kind of overkill for a homebrewer!!! Cheers!!!
 
My setup bears some scrutiny.

I have a bar style counter height fridge with 3 doors. The secondary regulators x6 are inside mounted with shutoff valves and (soon) complete flare nut swap out ability for sanke or corny kegs. All 6 regulators connected to single external gas line. There is a Y connection on the external line that connects to a beer mix tank and a co2 tank which share the common feed line.

The original plan was, if I am carbonating homebrew, shut off the beer mix, and turn on the co2 with the individual secondary regs opened on the kegs being pressurized, as well as any other serving kegs.
When I want to pour, switch off the co2 tank and also the carbonating keg (though probably doesn't really matter) and pour. In this scenario, I have noticed that when kegs are running low, the carbonation falls off, likely due to insufficient co2 partial pressure in my stout blend 25/75 beer mix over time.

Solutions at this point I think are:
1. Use CO2 for everything, and close the secondary reg shutoff on any nitro beers. When I want a nitro beer, turn off the co2 main reg valve, flip open the main beer mix reg and the nitro beer secondary reg. just leave it like this for the rest of the evening or however long that session, and revert back when I am done.
I think this is the simplest approach, and the brief contact periods of diminished co2 partial pressure likely will be inconsequential.

2. Install a dedicated nitro-only secondary regulator connected to the beer mix, separate from the manifold and use that exclusively for the nitro beer (I usually only have one on to at a time anyway). This would cost money however.

3. Drink more beer so as to avoid the carbonation level running low towards end of keg since it is being consumed at a faster rate. This is not going to happen unless I start throwing regular beer parties. This in turn would result in having less beer on hand since all my friends will be over at all hours begging for free beer. Not gonna be this option.

Why did I let Gary talk me into this ridiculous setup I have now....

TD
 
Option 2 is the only viable long term solution IMHO. Option one would work until you get sick of having to mess with it, and save up the money for option 2. Extremely odd that it wasn't set up that way to begin with. Then again, the 5/16" ID beer lines with a choker for a short run is really odd, and an "experienced" installer who insists that liquid CO2 defies the laws of physics is odd too.
 
Option 2 is the only viable long term solution IMHO. Option one would work until you get sick of having to mess with it, and save up the money for option 2. Extremely odd that it wasn't set up that way to begin with. Then again, the 5/16" ID beer lines with a choker for a short run is really odd, and an "experienced" installer who insists that liquid CO2 defies the laws of physics is odd too.

I agree totally, and it has taken me a while to accept the reality of my dilemma. As they say if you want something done right....

the gas is 5/16, the beer is 3/8 line.

Thanks

TD
 
The other time beer gas is used is for really long runs, where the line resistance would be greater than the serving pressure. Not really common amongst homebrewers, but used a lot in long draw set-ups in bars and restaurants.

In my research for setting up my keezer, this is what I understood it was used for. When a bar has the cooler several dozen feet away from the bar, it obviously requires a very long run of beer line to the taps. To push the beer that whole distance, there is a lot of head loss through the line, so they have to increase the pressure to force the beer that far. With regular CO2, this will significantly increase the carbonation levels to an unacceptable level. So they mix the gas with something that is significantly less dissolvable, like Nitrogen. So now, you can crank up the pressure without carbonating the ever living crap out of the beer.

For homebrewers, this is pretty much useless. Unless you store it downstairs and serve it across the house upstairs.

As for stouts, I had never heard that. Not saying it isn't true, just never heard it.
 
If your set up is allready running on CO2 leave it that way.
Beergas should be stored in a nitrogen tank with its own nitro-regulator.
As previosly mentioned nitro is most commonly used for stouts.
Therefore a stout faucet with the restrictor plate is needed.
Non stout beers can be run on nitro and i personally plan on doing so.
As to which styles that works well for and what it doesn't i couldn't tell you at this moment.After i run my MO-FUGGLE SMASH keg through the nitro i'll make a post about it but that will be a while off (MO-FUG is in primary atm)
--------
Cheers
 
On a somewhat related topic, is there a benefit to having a stout faucet over a standard faucet if you're just running co2 and no beergas or nitro?
 
Yesfan said:
On a somewhat related topic, is there a benefit to having a stout faucet over a standard faucet if you're just running co2 and no beergas or nitro?

Not that I'm aware of.
 
a stout faucet has a restrictor plate to reduce the high pressure of nitrogen.
there is no need for it unless you are using nitro.
the mo-fuggle smash is nice on the nitro as is the cider.
 
CO2 you get at the store and put into beer. It is colorless and oderless. Beer gas is the gas you get after you drink the beer. It does have a slight odor.:)
 
From draft-beer-made-easy dot com (google for more sources)

CO2. This is a naturally occurring gas that is highly soluble (dissolves easily) in beer. In fact, CO2 is a natural component of beer as a major byproduct of the fermentation process, another being alcohol. CO2 gives beer its characteristic head and provides a slight bittering in taste (a desirable quality in beer). CO2 also provides effervescence that helps “lift” the beer’s aromas into the drinker’s nose and palate.

N2. Another naturally occurring gas that is insoluble (hard to dissolve) in beer. Nitrogen has two similar purposes for use with draft beer: (1) to allow high pressure dispensing through heavily restrictive apparatus (causing notable frothing) as in Guinness and similar products; (2) to allow high enough gas pressures to overcome the resistance inherent in long beer lines. In both of these cases the goal is to push the beer at high pressure but not alter the carbonation of the beer as it sits in a keg. This is accomplished by using insoluble Nitrogen mixed with the soluble CO2. More on gas mixing in a moment.

BeerGas – This pre-blended gas is a blend of Carbon Dioxide (25%) and Nitrogen (75%) made specifically for use with Guinness Stout and other similar beers. This mix is used to allow the high pressures needed to force the beer through a restrictor plate in a specialty faucet. This is to create the frothy pours characteristic of this style. In this type of application, the use of CO2 alone would quickly over carbonate the beer and pouring would be impossible. This mix is also very commonly, but incorrectly, used to pressurize the long line draft systems common in many restaurants and bars. This is not the proper ratio of mixed gases to serve standard ales and lagers. Beer Gas is however, the only pre-blended gas commonly available – creating confusion over its proper usage.
 
the gas is 5/16, the beer is 3/8 line.

TD

if the line is short (5 feet or so) the beer line should be 3/16"inside diameter, not 3/8"

2.4 v/v or 2.5 v/v CO2 (typical carbonation for microbrew/craft/homebrew ales) at 38deg F would require about 14PSI of 100% CO2 to maintain the correct carbonation level.

To balance your pour speed with this pressure you need 14lbs. of restriction

1 lb for cooler hardware (on a direct draw it is less)
0.5 lb for each foot of vertical rise from the centre of your keg to the faucet
(assuming a beer tower on top of your counter that would be about 2')

that gives us 1 to 2 lbs so far leaving 12 to 13 lbs to make up with choke line.

3/16" ID vinyl tubing provides approximately 2.5 lbs of choke per linear foot

12.5/2.5=5 feet of 3/16" vinyl tubing.

unless you are serving a beer with a wildly higher or lower carbonation level (like Guinness at 1.2 v/v, or some Belgians up to 2.9 or 3.0 v/v) then ALL direct draw/kegerator/Keezer setups should have 5 feet of 3/16" ID vinyl tubing between the keg and the faucet.

with long line systems the rules change and that is where beer gas comes in.

Many bars use beer gas (25% CO2, 75% nitrogen: AKA stout gas) because they require pressures exceeding 18 PSI to push the product from cooler to bar. This allows them to prevent overcarbonation as previously posted, but does not provide sufficient CO2 to maintain carbonation so the beer will get progressively flatter.

Overcarbonation is a major issue in a bar because it produces 'wild' beer and excessive foam which affects the bottom line very dramatically.

Premixed/bottled beer gas in this circumstance is an imperfect solution.

Undercarbonation also affects the bottom line because because it affects presentation and product quality, but must dramatically because if you only have 1/4" of head instead of 5/8" of head then you have given away 3/8" of free beer when you fill the glass.

'SMART' bar owners use blended gas with blends tailored to their dispense pressure (like the McDantim blenders, like the Micromatic blenders (which BTW are McDantim blenders)) So at for example at 28 psi dispense pressure, you can maintain carbonation in a 2.4 v/v beer with a 50% CO2 50% N2 blend. If you have a different dispense pressure then change the blend. Perfect presentation to the end of the keg, consistent product, consistent pour, maximized yield.

BTW. I work in draught system installations and my employer is one of North America's largest Micromatic distributors.
 
On a somewhat related topic, is there a benefit to having a stout faucet over a standard faucet if you're just running co2 and no beergas or nitro?

The purpose of a creamer or stout faucet is to provide enough agitation to the beer to break almost all of the CO2 out of solution and produce a thick creamy head.

It was intended to mimic the type of product dispensed from a hand-pump or 'beer engine" used for dispensing cask ales.

Cask ales have notably low carbonation levels due to the permeability of the wooden casks. Think of the beer in your secondary fermentation... it looks still and the airlock activity is minimal, but if you agitate or shake it you get a head of foam and the airlock roils vigorously. That is the carbonation level of a cask ale.

If this product is pulled from a cask with suction (beer engine) that CO2 will be pulled out of solution and a thick creamy head results.
 
Micro-matic's blenders have pre-set balance percentages, but with McDantim blenders, you can adjust the blend% to whatever you want.

Micromatic's blenders are made by McDantim.

remove the small screw in the centre of the round brass piece and insert a 1/16" allen key. each full turn clockwise increases the CO2 % by approximately 3%. To reduce the CO2 % by 3% turn 2 turn counterclockwise followed by 1 turn clockwise.

test with a gas analyzer to verify.
 
schroeder said:
unless you are serving a beer with a wildly higher or lower carbonation level (like Guinness at 1.2 v/v, or some Belgians up to 2.9 or 3.0 v/v) then ALL direct draw/kegerator/Keezer setups should have 5 feet of 3/16" ID vinyl tubing between the keg and the faucet.

I strongly disagree. I've taken the micromatic class, and they unfortunately ignore some basic principles of fluid mechanics. All of those equations and line resistance tables are designed to pour beer that's being stored and served between 36° and 38°, and has moderate carbonation levels (<2.7 vol). They're also designed to result in a flow rate of about 128 oz/min, which is the fastest that beer carbed to ~2.7 vol and stored at 38° can be poured without excessive foaming. For warmer serving temps the flow rate needs to be slower and gentler to prevent foaming. Just a couple degrees makes a huge difference. And since line resistance is a function of flow rate, all of those resistance tables and equations are useless for slower flow rates. Because line resistance decreases as flow rate decreases, the lines need to be much much longer to slow the flow down just a little bit.

For bars and restaurants those equations and tables usually work fine, because they're keeping the beer very cold, and they want to be able to pour beer as fast as possible without excessive foaming. For the home brewer who may want to serve beer slightly warmer, and likely doesn't care if it takes a couple extra seconds to pour a pint, longer lines are probably a much better option. Other than a very slightly slower pour, there aren't any disadvantages to using extra long lines. The advantage is that they allow greater flexibility and the option to serve beers with higher carb levels or warmer serving temps.

Then again, if you listen to micromatic you'll be afraid to store/serve your beer even one degree higher than 38°, so their tables and equations will work fine. I've seen the poor sanitation practices at bars and restaurants when switching kegs, pouring beer, and cleaning lines/faucets, so I understand why breweries and distributors would want to keep the beer cold. Homebrew with proper sanitation practices doesn't have the same risks, and as evidenced by this forum, many if not most homebrewers prefer to store and serve their beer warmer than 38°.

FWIW there does exist a line balancing calculator that follows the principles of fluid mechanics rather than assuming that we all want to use one specific temperature and flow rate. You have to choose the flow rate you want though (in terms of a pint fill time), which can take some trial and error depending on the serving temp. The spreadsheet can be found here-
https://docs.google.com/spreadsheet/ccc?key=0ApGb-vIKLq7FdGtzN3BrY2xZSldORzQ2bHVVX0hzaEE#gid=0
 
Schroeder,


Glad to have you here bringing real world experience to the thread.

In my home system, I dispense to the outdoors where the lines are kept reasonably cold using a forced air tower and blower in the cooler.
I am getting acceptable performance from my setup.
What I have adopted for dispensing stout is as follows. Recall my gas line in has a Y, with one limb connected to a beer gas cylinder, and the other to a co2 cylinder, and the output feeding the "manifold" for the secondary regulators inside the beer cooler. I leave the beer gas primary reg turned off, and the co2 cylinder on. Both set at 50 psi.
When dispensing stout, the keg is pressurized to 32-33 psi with beer gas blend 75:25.
Pour a pint, or two, or three or more. Wen dispense pressure begins to drop too low that I'm nor getting a good pour I do the following:
Turn of co2 primary reg valve. Turn ON beer gas primary reg valve. Turn on stout keg secondary reg valve. Wait several seconds. Turn off secondary reg valve to stout, and then beer gas primary off, and then co2 back on.

Been working pretty good, and way better than before, when I was trying to dispense all products with beer mix. I should've realized what would happen.

I do want to add a small brass manifold so I can connect more kegs (as cooler will hold 9, but tower only can serve 6) to CO2 pressure for carbonation of fresh homebrew, or even while lagering if I want to carbonate at the same time. I think I would need to add a fitting to the last regulator body in the daisy chain, to which I would connect a barbed or flat nut fitting. From that I would need to connect to another regulator that I'd have to scrounge up, and then connect that to a new 3-4 port brass manifold so as to avoid buying multiple regulators for carbonation. I

I'm also thinking about removing the Y on the gas in side and running a separate beer gas only line into the cooler with a flare nut so I can dispense commercial Guinness or corny keg stout home brews setting pressure just with the primary tank regulator and no secondary regulator. I think I need to drill a hole to do this though, and have been reluctant to do so, since its working good like it is.

TD
 
I'm also thinking about removing the Y on the gas in side and running a separate beer gas only line into the cooler with a flare nut so I can dispense commercial Guinness or corny keg stout home brews setting pressure just with the primary tank regulator and no secondary regulator. I think I need to drill a hole to do this though, and have been reluctant to do so, since its working good like it is.

TD

That setup sounds preferable from my perspective, but if you want greater flexibility there is another alternative.
I am goingtoassume that the secondary regulators in your cooleraresimilarin design to the ones manufactured by Cornelius/Taprite/Micromatic etc being that there is a guage dialon thew top, a shutoff valve or barb on the bottom at the outlet, and 2 barbs on the sides,or a barb and a plug, which are the regulator high side,or inlets.

if you drill the second hole in your fridge and run your stout gas line into the fridge...

replace the barbs/plug in the sides of the last secondary regulator with gas cocks. connect CO2 to one side,and stout gas to the other. Open the gas cock for the blend that you want to use for the product that you have connected (and close the other gas cock naturally)
 
That setup sounds preferable from my perspective, but if you want greater flexibility there is another alternative.
I am goingtoassume that the secondary regulators in your cooleraresimilarin design to the ones manufactured by Cornelius/Taprite/Micromatic etc being that there is a guage dialon thew top, a shutoff valve or barb on the bottom at the outlet, and 2 barbs on the sides,or a barb and a plug, which are the regulator high side,or inlets.

if you drill the second hole in your fridge and run your stout gas line into the fridge...

replace the barbs/plug in the sides of the last secondary regulator with gas cocks. connect CO2 to one side,and stout gas to the other. Open the gas cock for the blend that you want to use for the product that you have connected (and close the other gas cock naturally)

That is rather ingenious! Thanks! I think it'll be challenging to plumb in that just because of my physical layout.

My cooler is setup as follows. Perlick, back bar unit I believe. Compressor on left, three doors to right, and its bumped right against the wall/corner on the right side. So gas line comes in on left, where there is room for the cylinders. I'd have to run a gas line all the way to the end of the cooler to connect to the last secondary. My salesman kinda screwed up from the beginning, seling me a four product dispense, when I wanted a 6. We got that fixed, but still only had 4 secondary regulators. The installer graciously gave me 2 for free which aren't as nice as the Perlick's (harder to adjust and seem less sturdy). Those two are on the end of the line. I suppose they'll work fine however, though will need to ensure they both have the dual barb/plug tapped. Can't imagine they wouldnt.

Do you know a source for the gas cocks? and also, been considering replacing the existing gascocks with ones with integral check valves.

Thanks again!

TD
 
I have not ever been a fan of the Perlick gas cocks on those regulators. I found that if they fail they are a PITA to check, and I have had many installs where we have removed and replaced them all (generally older installs so newer hardware may be fine)

The Perlick secondary regulators are tapped with 1/4" fpt on both sides (as well as top and bottom)

You can find the gas-cocks at most homebrew shops, Micromatic or Foxx Equipment websites, or several others.
 
Back
Top