Keg conditioning vs force carbonation.

[sawbossFogg]

Anyone have a good reason for naturally conditioning kegs when force carbonating is so much faster and more reliable?

 

[twalte]

Subscribed...if there is a reason, would love to know.

 

[mikescooling]

Some people (myself) think it gives a smoother beer. The monks do it that make Duvel, and a few others do it as well. What do I do? I keg everything of course.

 

[Neerdowell]

Might be academic from a homebrewer's standpoint, but if pride is an issue and you want to brew your German styles according to the reinheitsgebot, forced carbonation is out unless your using the C02 that is a by-product from fermentation, or so I've heard. Saving C02 is way beyond any current goals for me.

Perhaps a more useful reason was mentioned in the Nov/Dec 2012 zymurgy - krausening by adding an active fermenting yeast can help eat up remaining diacetyl. I have yet to try this, though. I usually just save about a liter of unfermented wort in sanitized bottles as gyle for conditioning my kegs.

The main reason I naturally carbonate, though, is to save my keezer space for my carbonated kegs. I can naturally carbonate while the keezer is full and the C02 expenditure to force carbonate is greater at higher temperatures.

 

[sawbossFogg]

It's been on my mind as I like to prime my kegs w beergas, which I of course cannot do naturally. I don't force carbonate in my keg fridge because I believe colder liquids will require more time to get gases into solution. I think i should be using wort as well, however I've really had challenges getting the right proportions (whatever sugars used) even using BeerSmith tools etc. I suppose it is unnecessary and arguably wasteful to use the canned co2, but that hasn't concerned me. I do like bottling as well and priming bottles has been pretty easy. I don't have the means to lager and German zeitgeist doesn't concern me other. I'll keep trying natural carbonation, hell I can always put gas into it.

 

[JuanMoore]

It's been on my mind as I like to prime my kegs w beergas, which I of course cannot do naturally. I don't force carbonate in my keg fridge because I believe colder liquids will require more time to get gases into solution.

Using beergas to carbonate takes a lot longer, uses up a more expensive product, and doesn't have any benefit. Carb with CO2 (forced or naturally) and then serve with beergas through a nitro faucet. What the beergas does is allow a higher serving pressure without severely overcarbonating the beer.

And FWIW gasses are actually significantly more soluble in liquids at lower temps.

 

[sawbossFogg]

Jaun, I really like serving nitro beer and I'm glad you're interested, but I have a couple strong disagreements, based on experience. First, when breweries condition beer in Brite tanks, if the beer is going to be served on Beergas it MUST be conditioned that way. That is because CO2 is much more soluble than nitrogen and what you have in a bottle to push beer with is simply used for that, to push, whats in solution is a different matter. Heres an example, if you buy a keg of carbonated beer and attempt to serve it with beer gas, even at low pressure you'll be putting carbonated beer through a nitro faucet and you'll get foam! I tried this many times and until I asked several different breweries how I should go about it, I didn't get it right. The only functional method is to flatten carbonated beer and start over with beergas to get nitrogen into solution. This method takes about 4 days for a qtr barrel (at room temp). I find that my 40 cu ft bottle of beergas lasts a very long time and it only costs $30 to fill so...
As far as gas being more or less soluble at differing temps in liquids, I think thats a simple matter of physical chemistry whereby colder liquid molecules are slower and more dense. Breweries probably keep their brite tanks at fridge temps for freshness, but if you want to speed up physical processes, warm things up. Hey, I'm always up for learning something new, maybe there's call for another thread.

 

[JuanMoore]

Jaun, I really like serving nitro beer and I'm glad you're interested, but I have a couple strong disagreements, based on experience. First, when breweries condition beer in Brite tanks, if the beer is going to be served on Beergas it MUST be conditioned that way. That is because CO2 is much more soluble than nitrogen and what you have in a bottle to push beer with is simply used for that, to push, whats in solution is a different matter. Heres an example, if you buy a keg of carbonated beer and attempt to serve it with beer gas, even at low pressure you'll be putting carbonated beer through a nitro faucet and you'll get foam! I tried this many times and until I asked several different breweries how I should go about it, I didn't get it right. The only functional method is to flatten carbonated beer and start over with beergas to get nitrogen into solution. This method takes about 4 days for a qtr barrel (at room temp). I find that my 40 cu ft bottle of beergas lasts a very long time and it only costs $30 to fill so...
As far as gas being more or less soluble at differing temps in liquids, I think thats a simple matter of physical chemistry whereby colder liquid molecules are slower and more dense. Breweries probably keep their brite tanks at fridge temps for freshness, but if you want to speed up physical processes, warm things up. Hey, I'm always up for learning something new, maybe there's call for another thread.

The majority of the small bubbles and cascading head effect from a nitro faucet is from the beer being forced through the small holes in the restrictor plate at high pressure, breaking the bubbles up, not from the tiny amount of nitrogen in solution. Plenty of breweries carbonate their nitro beers with pure CO2 and then use beergas to serve, so I'm not sure where you're getting the info that it MUST be conditioned with beergas. You can get the same cascading head effect without any nitrogen. You can push with high pressure through the nitro faucet using pure CO2 and get the same effect, you just can't leave it at that pressure for any length of time or it will severely overcarbonate the beer. I believe it was Yuri who experimented with using pure argon to push a carbonated beer through a nitro faucet, and he reported that it worked just as well as beergas.

As for buying a keg of carbonated beer and serving it through a nitro faucet, the reason that it typically produces a ton of foam is that it's usually overcarbed for a nitro faucet. Most commercial beer is carbed to ~2.7 vol, and anything over ~2.0 vol is asking for trouble with a nitro faucet. Degas the keg to ~1.8 vol and it should pour fine, even without any "conditioning" time on the beergas.

Gasses being more soluble in liquids at colder temperatures is a well known fact, and an example of Henry's law. Even if you're not familiar with chemistry or Henry's law, it should be obvious just by looking at any carbonation chart. By warming things up, you're both slowing down the carbonation process, and reducing the total carbonation possible at a given pressure. I keep most of my beers at 40°F and 11 psi for a carbonation level of 2.4 vol. To get that same level of carbonation at 65°F I'd have to increase the pressure to 27 psi.

Here's a graph showing CO2 solubility in water at 1 atm-

Here's one for nitrogen, also at 1 atm-

 

[bottlebomber]

I have strong disagreements too Juan, and would also like to add that you are an *******

 

[JuanMoore]

I have strong disagreements too Juan, and would also like to add that you are an *******

Hah! Well, I figure that last part is a given. :cross:

 

[sawbossFogg]

Ok thanks for the toolbox graphs, sounds good. You can pour your carbonated beer through your nitro faucet if you like, but I've tried it quite a bit and its ****ed, so I'll stick with 75% nitrogen beer gas because I can afford it

 

[sawbossFogg]

Ok you've got me considering carbing at a lower level and pushing it through my nitro faucet, which begs the question; Is every pub and manufacturer throughout the world that uses beer gas a complete *******?

 

[mmb]

Ok thanks for the toolbox graphs, sounds good. You can pour your carbonated beer through your nitro faucet if you like, but I've tried it quite a bit and its ****ed, so I'll stick with 75% nitrogen beer gas because I can afford it

That's fine, but you're wasting the nitro. It doesn't dissolve into solution like CO2 does and "carbonate."

Ok you've got me considering carbing at a lower level and pushing it through my nitro faucet, which begs the question; Is every pub and manufacturer throughout the world that uses beer gas a complete *******?

No, but they do understand fluid dynamics and the effects of a gas dissolving into a liquid. Clearly, you're having difficulties with the concepts.

 

[Bobby_M]

Gasses being more soluble in liquids at colder temperatures is a well known fact, and an example of Henry's law. Even if you're not familiar with chemistry or Henry's law, it should be obvious just by looking at any carbonation chart. By warming things up, you're both slowing down the carbonation process, and reducing the total carbonation possible at a given pressure. I keep most of my beers at 40°F and 11 psi for a carbonation level of 2.4 vol. To get that same level of carbonation at 65°F I'd have to increase the pressure to 27 psi.

And...?

I'm not getting into the Nitro vs. CO2 debate but the point about warm beer carbing faster than cold beer does have merit. Note that we ALL should agree that Henry's law supports greater gas solubility at lower temps, but it is pressure dependent. The volumes of CO2 chart is based on these laws. HOWEVER, warmer beer SHOULD carb faster when the pressure has been compensated for that elevated temperature.

I'll give an example just in case I'm not clear: The chart here: http://www.kegerators.com/carbonation-table.php suggests that you can achieve 2 volumes of CO2 at:

38F and 6psi

or

65F and 20psi

Now, using the set and forget method, I support the claim that 65F @ 20psi should reach 2 volumes of CO2 faster. Why? Kinetics, Fick's Law, etc. The rate that gaseous CO2 dissolves into beer has to do with the concentration delta between the headspace and the surface of the beer. As it dissolves, that new high concentration of CO2 will diffuse away from the surface a lot faster if the beer is warm.

Of course it would require that you have a separate regulator port for carbing warm beer because you're not going to be serving off the same pressure. I have a separate tank and reg for carbing my cellared kegs. Granted, I'm not doing this for carbing speed but rather just the ability to carb beers that are on deck.

 

[JuanMoore]

Ok you've got me considering carbing at a lower level and pushing it through my nitro faucet, which begs the question; Is every pub and manufacturer throughout the world that uses beer gas a complete *******?

I said earlier that the majority of the creamy mouthfeel and cascading head effect was from the pressure and restrictor plate, but some of it is from the nitrogen too. If you want the benefit of the nitrogen but don't want to wait for ages for the beer to carbonate using beergas, you could buy a carb stone. I didn't mean to presume to tell you how to do things though. If you have a process that works well for you and you're happy with, use it.

And...?

I guess I assumed that they were talking about constant pressure since they mentioned doing it at room temp in a sankey keg with a 25/75 beergas blend. Not sure why I assumed that, maybe the apfelwein I was drinking had something to do with it. I know sankey kegs can handle more than the 60psi max they're rated for, but IMO trying to carb with beergas at room temp is going to push the pressure way past the point of being dangerous. Even at 40°F the pressure required for 1.8 vol of carbonation is pushing the max rating for the keg.

 

[sawbossFogg]

Well, there's good learning here for me thanks. Of course Nitrogen gas can dissolve into solution as logic and Jaun's graph from the engineering toolbox would suggest. The questions are a liquids capacity at given temperatures, and as Bobby points out rate and time.
My example was a Porter I bought repeatedly from Odell in Fort Collins. There I was told that the beer that was distributed for nitro service was prepared in brite tanks separate from the carbonated brite tanks (possibly simply at lower volumes of co2) and those were only available in half barrels. Since I was interested in dealing with quarter barrels and this was long before I found HBT, through many conversations and several varying attempts, including, first pushing beer too highly carbed through my nitro faucet, second flattening the beer to various degrees and pushing with beergas through the nirto faucet and lastly with success, flattening the beer and recarbing it with the beer gas. All of which seemed to happen faster at warmer temps and higher pressures. What I will try after reading this lively diatribe, is to naturally carb my sankey kegs for lesser volumes and push them with beer gas through my faucet, that is worth a try, thanks!
Nonetheless, my original post, like so many others I have subsequently found and read, was asking for opinions regarding the merit of natural vs force carbonation. Whereby we learned a bit more about German beer religion, personal pride, etc in this in this post, my answer to this question came in other posts where many folks discuss this topic and specifically talk about patience and the bit of aging time required for bottling and natural carb being the key to the matter regardless of carbonating method.

 

[JuanMoore]

Nonetheless, my original post, like so many others I have subsequently found and read, was asking for opinions regarding the merit of natural vs force carbonation.

Many people feel that natural carbonation produces smaller bubbles and a creamier mouthfeel. Many people can't detect any difference. I tend to think that there is a difference, but that it's pretty minimal.

 

[brewtime]

Ok you've got me considering carbing at a lower level and pushing it through my nitro faucet, which begs the question; Is every pub and manufacturer throughout the world that uses beer gas a complete *******?

carbonate you beer at lower levels and then use the mix to push.

 

[bknifefight]

the main reason i naturally carbonate, though, is to save my keezer space for my carbonated kegs. I can naturally carbonate while the keezer is full and the c02 expenditure to force carbonate is greater at higher temperatures.

+1

 

[mmb]

Well, there's good learning here for me thanks. Of course Nitrogen gas can dissolve into solution as logic and Jaun's graph from the engineering toolbox would suggest.

You'll find that N2 is considered insoluble (hard to dissolve) into beer and is thus used for high pressure draft systems for overcoming resistance in long haul lines because it won't affect carb volume like using standard CO2 in these situations.

Even the graph covers that. N2 doesn't carbonate beer at any of the pressures used to dispense it.

 

[sawbossFogg]

You'll find that N2 is considered insoluble (hard to dissolve) into beer and is thus used for high pressure draft systems for overcoming resistance in long haul lines because it won't affect carb volume like using standard CO2 in these situations.

Even the graph covers that. N2 doesn't carbonate beer at any of the pressures used to dispense it.

The N2 graph references solubility as a function of temperature. Please, Sparky enlighten me.

 

[mmb]

The N2 graph references solubility as a function of temperature. Please, Sparky enlighten me.

At about a hundredth that of CO2. Perhaps you missed

N2 doesn't carbonate beer at any of the pressures used to dispense it.

Reading is fundamental.

 

[sawbossFogg]

At about a hundredth that of CO2. Perhaps you missed

Reading is fundamental.

Ahh, got it. Not saying your wrong, just working through it. In fact for interest sake, I just poured a bit of an Imperial Stout that sat on the beer gas at 45 F for 4 days at 30 PSI and yeah its pretty much flat, whereas if it were CO2 it'd be overcarbed. The last chart/intel I need to find is what are ideal carb units for preparing to push w beer gas are, in the past I've had over-carb issues.

And since were being ********, I'll mention that it's also fundamental not to crap the bed in the World Series!

 

[gizmodog51]

to answer the original question......

after reading an interesting thread on pressure fermenting....i decided to try my hand at it.

i had experience keg conditioning, which to me is dosing the already fermented beer that's in the keg with corn sugar, beet sugar I.E. whatever a person might use for priming.

force carbonation, shoot the keg with CO2 at specified pressure kept at controlled temp for a period OR roll the keg around let it set and check by tapping.

have done both of these methods but after reading the aforementioned article i decided to ferment till bubbler was showing only one bubble @ minute. then rack over to keg add 1/4 C priming sugar...i use beet sugar.
this kicks the pressures up to just a hair below 40 psig on my spunge valve.
pressures may have gone to 40 psi and activate the preset blow-off but if so i never saw the guage at 40. so far i haven't been around when the blow off has occured, if ever. so i'd say mostly 37-39ish...psig in keg.
i usually leave the beer under pressure for several weeks....then cold crash for a couple days...release the pressure and tap.
i'm VERY happy with this method. the cascading small bubbles and great head to almost the empty class is great. it is especially enjoyable in a dark to medium colored beer. one would swear it was beer gas carbed poured thru a creamer tap.
also this has helped to cut down on gas useage.
since my experience with this method i don't carb anyother way.
yes there is a small amount of trub in the first glass but if i'm careful and not to concerned about every last drop from the carboy the amount will be small and worth the effort and the beer, from then on is Kystral klear. uless a wit or hefe.

GD

 

[JuanMoore]

In fact for interest sake, i just poured a bit of an Imperial Stout that sat at 45 F for 4 days at 30 PSI and yeah its pretty much flat, whereas if it were CO2 it'd be overcarbed. The last chart/intel I need to find is what are ideal carb units for preparing to push w beer gas.

Using 25/75 beergas? Even if you let it reach equilibrium over several weeks at that temp and pressure you'd only have ~0.9 vol of carbonation. 1.0-1.8 vol is pretty standard carbonation for serving through a nitro faucet. Here's a carbonation calculator designed for beergas that you might find useful-

http://mcdantim.mobi/easypsig.html

 

[sawbossFogg]

Thanks! The Beer Gas I buy from AirGas corp I think is the standard 75%N2-25%CO2

After all this, I just took the keg I've had canned for a week and on the beer gas for a little less than that, released the pressure and put in on about 10 PSI of CO2 and gave it about 50 lap rolls. I'll pr let it sit for a week, pour it through the faucet and go from there. And if I were to be at a predicted ~2 Volumes CO2 the worksheet you've shared suggests dispensing at 17 PSI. Interesting stuff.

 

[sawbossFogg]

This method sounds pretty fun, I've heard a bit about it before, seems fairly logical. Can you provide any info on the article referenced?

 

[Shooter]

As to the original question, my keezer has room for three kegs, one is usually a five gallon commercial keg, and two full of homebrew. Since I have four other kegs, I just transfer the beer to a keg and let it age for another month or so until a tap frees up. Since it's just going to be sitting there anyway, it might as well be carbonating at the same time. That is why I prime with sugar, no other reason.

 

[emjay]

Ahh, got it. Not saying your wrong, just working through it. In fact for interest sake, I just poured a bit of an Imperial Stout that sat on the beer gas at 45 F for 4 days at 30 PSI and yeah its pretty much flat, whereas if it were CO2 it'd be overcarbed. The last chart/intel I need to find is what are ideal carb units for preparing to push w beer gas are, in the past I've had over-carb issues.

And since were being ********, I'll mention that it's also fundamental not to crap the bed in the World Series!

The whole reason nitrogen is used at all is BECAUSE it barely dissolves (it will a tiny bit, but it's negligible). It allows you to push beer at the higher pressures required due to the restrictor plate, WITHOUT the subsequent overcarbing that you'd get if you used solely CO2 at those pressures.

It's not because the nitrogen itself gives the beer a different quality - ANY insoluble gas (like argon, as previously mentioned) will accomplish the exact same thing. In fact, 100% argon (and less frequently, 100% nitrogen) is used to push wine and other still beverages through a draught system for precisely the same reason... since it doesn't dissolve, it won't start carbonating (or otherwise make sparkling) the wine no matter how long you keep it on the gas for.

 

[sawbossFogg]

At about a hundredth that of CO2. Perhaps you missed



Reading is fundamental.

The whole reason nitrogen is used at all is BECAUSE it barely dissolves (it will a tiny bit, but it's negligible). It allows you to push beer at the higher pressures required due to the restrictor plate, WITHOUT the subsequent overcarbing that you'd get if you used solely CO2 at those pressures.

It's not because the nitrogen itself gives the beer a different quality - ANY insoluble gas (like argon, as previously mentioned) will accomplish the exact same thing. In fact, 100% argon (and less frequently, 100% nitrogen) is used to push wine and other still beverages through a draught system for precisely the same reason... since it doesn't dissolve, it won't start carbonating (or otherwise make sparkling) the wine no matter how long you keep it on the gas for.

sounds good