Forced carbonation vs serving

[siouxalumn]

I'm extremely new to home brewing. I used to do it pre-pandemic with a self contained apparatus that did most of the work for you. now, I'm in a newly built home with a proper bar/kegerator and I want to start brewing my own 5 gal kegs for the bar. So I'm reading as much as I can, and just purchasing my equipment, so be nice and dumb it down a bit for me for what I assume is a stupid question.
I'm confused about carbonating to X vols. and then serving at a different pressure. Assuming I want 2 volumes co2 at 40 degrees, the chart says to carbonate at 7 psi. If I put newly brewed beer at 7 psi of a period of time, 1-2 weeks, does it eventually stabilize and stay at that carbonation rate (2.01) indefinitely. If I then need to serve it at 12 psi, will it over carbonate, or is the carb rate fixed? As you can see, I'm at a loss on the concept of carbonating at one pressure and serve at another.

Thanks!

 

[shoengine]

Where did you come up with 12 PSI serving pressure?

 

[Broken Crow]

So I'm reading as much as I can, and just purchasing my equipment, so be nice and dumb it down a bit for me for what I assume is a stupid question.

Thanks for saying that part! Too many people have inherent ego issues that end up making it like pulling teeth to answer a simple question.
I looked at your other posts and I suspect the confusion may have come about by your quest to use 'beer gas' (that non-traditional Guinness invention of the 1950's) which requires carbing first on pure CO2 to achieve desired CO2 volume and then serving on beer gas at a much higher pressure without comprimising carb volume.
The desired CO2 volume is your serving pressure unless using beer gas.

 

[sibelman]

A detail: if, for some reason (beer line lengths for example), you wish or need to serve at a different pressure than you carb, you would adjust the pressure during serving and then set it back to the carbing pressure. It takes some time for pressure changes to influence the carbonation level in the serving keg, so these somewhat inconvenient shifts in pressure won't cause trouble.

For what it's worth, I generally serve at the same pressure I carb, which varies a bit between beers in my four-tap kegerator. Using flow-control taps can help compensate for the variation.

None of what I've said relates to using beer gas - I only use CO2.

 

[Bassman2003]

I'm extremely new to home brewing. I used to do it pre-pandemic with a self contained apparatus that did most of the work for you. now, I'm in a newly built home with a proper bar/kegerator and I want to start brewing my own 5 gal kegs for the bar. So I'm reading as much as I can, and just purchasing my equipment, so be nice and dumb it down a bit for me for what I assume is a stupid question.
I'm confused about carbonating to X vols. and then serving at a different pressure. Assuming I want 2 volumes co2 at 40 degrees, the chart says to carbonate at 7 psi. If I put newly brewed beer at 7 psi of a period of time, 1-2 weeks, does it eventually stabilize and stay at that carbonation rate (2.01) indefinitely. If I then need to serve it at 12 psi, will it over carbonate, or is the carb rate fixed? As you can see, I'm at a loss on the concept of carbonating at one pressure and serve at another.

Thanks!

Kegging and carbonation is kind of complicated. I always used the "set and forget" approach to kegging. Which requires more time/patience but is more predicable. Basically, as mentioned above, you set your desired carbonation for your style of beer and what can be accomplished with your system (serving line length etc...) and hook up the CO2 gas. Let this sit for two weeks and it will not change unless you do something to change it. The rest of the keg's life will have predictable carbonation.

To save time, the other way is to force a higher amount of CO2 in the beer than you will be serving at. Say 30PSI for 3 days. Then letting that calm down to a lower serving pressure.

Bottom line, these changes in carbonation take time as it takes time for the CO2 to make its way in to the beer. So anything related to kegging needs to take place over some time. The less you rush the more predicable it behaves.

The goal is to have your kegging system "balanced". What does that mean? It means the beer in the keg is equal to the back pressure coming from the CO2 tank. If it is not equal the gas will come out of solution (foam) in the lines or the beer will eventually become over carbonated. Either way, you will not be able to pour it easily.

The "set and forget" method uses the same pressure from the tank for carbonating and serving, so you will end up in balance given a week or two of time.

 

[mac_1103]

If you're going to use the set and forget method, then you should just set and forget. Why do you want to serve at a higher pressure?

 

[siouxalumn]

Where did you come up with 12 PSI serving pressure?

https://content.kegworks.com/blog/determine-right-pressure-for-your-draft-beer-system/

I have a two tap system that is running on one Co2 regulator so they are at the same serving pressure. I use Perlick Flow Control faucets to date, but have been serving commercial kegs that I assume come pre carbonated. I'm switching to homebrew so that will not be the case so I want to understand the relationship.

 

[siouxalumn]

Thanks for saying that part! Too many people have inherent ego issues that end up making it like pulling teeth to answer a simple question.
I looked at your other posts and I suspect the confusion may have come about by your quest to use 'beer gas' (that non-traditional Guinness invention of the 1950's) which requires carbing first on pure CO2 to achieve desired CO2 volume and then serving on beer gas at a much higher pressure without comprimising carb volume.
The desired CO2 volume is your serving pressure unless using beer gas.

Thank you. "The desired CO2 volume is your serving pressure unless using beer gas." That is the simple answer to the question I was looking for. I was experimenting with a commercial Bitter that would benefit from N in my previous post, and may dabble with some stout in the future, but that's a different animal all together.
My current setup has two taps with one regulator so I've been using Flow Control faucets to manage the flow rate and foam from two different kegs. Just trying to get my head around the relationship between carbing to X and if I push it out of the keg at a different psi, is that going to over/under carb that keg, because the other keg is carbed and served at the same psi.

 

[shoengine]

https://content.kegworks.com/blog/determine-right-pressure-for-your-draft-beer-system/

I have a two tap system that is running on one Co2 regulator so they are at the same serving pressure. I use Perlick Flow Control faucets to date, but have been serving commercial kegs that I assume come pre carbonated. I'm switching to homebrew so that will not be the case so I want to understand the relationship.

So you used the equation and got 12?

 

[siouxalumn]

A detail: if, for some reason (beer line lengths for example), you wish or need to serve at a different pressure than you carb, you would adjust the pressure during serving and then set it back to the carbing pressure. It takes some time for pressure changes to influence the carbonation level in the serving keg, so these somewhat inconvenient shifts in pressure won't cause trouble.

For what it's worth, I generally serve at the same pressure I carb, which varies a bit between beers in my four-tap kegerator. Using flow-control taps can help compensate for the variation.

None of what I've said relates to using beer gas - I only use CO2.

Thanks. That's what I've been doing with my commercial kegs. Just making sure it will work with homebrew.

 

[siouxalumn]

So you used the equation and got 12?

No, I used the chart. Serving an Ale and a Lager with the same regulator so split the difference. It's not a long pour system, just a kegerator.

 

[siouxalumn]

If you're going to use the set and forget method, then you should just set and forget. Why do you want to serve at a higher pressure?

2 Kegs on the same regulator.

 

[shoengine]

No, I used the chart. Serving an Ale and a Lager with the same regulator so split the difference. It's not a long pour system, just a kegerator.

Ah, that does require tough choices. I would Just disconnect the QD when not using the 2.1 volumes beer to avoid over-carbonating, or maybe using an inline valve until you get separate regulators.

 

[mac_1103]

2 Kegs on the same regulator.

I think you're over-complicating things. I have three kegs on the same regulator. I picked one pressure that gives me a carbonation level I like and pours well. I don't worry about whether the IPA is slightly over-cabonated or the Brown Ale slightly under according to some style guide.

 

[playhouse]

I force carb my beers overnight using a carbonation calculator that considers beer volume, beer temperature, keg volume, applied CO2 pressure, desired serving pressure, and time. You can find the original calculator here, make a copy, and modify as you see fit. I have force carbonated over 100 batches and never had a problem with over carbonation. A typical force carb is 30-36 psi for 12-16 hours depending on the beer style and then releasing the 'high' pressure and repressuring to the desired serving pressure. I usually cold crash my beers before force carbonating to lower the beer temperature as CO2 goes into cold beer more efficiently.

 

[Climb]

@siouxalumn - To solve your problem of serving two different beers that need different CO2 volumes and thus different serving pressure, a dual secondary regulator would really help you. There are two primary types of secondary regulators, take a look at this (but idealy find one with MFL instead of barbed fittings) or duotight secondary regulators. Keep in mind that the length of beer line should ideally be different too.

Off topic - But since you are buying gear, currently serving commercial beers, I assume in Sanke kegs; have you thought about fermenting and serving (not necessarily fermenting and serving in the same keg) your homebrew in Sanke kegs? I struggle to understand why so many home brewers are so partial to corny kegs. The main reason I hear, that makes some sense to me, is that you can reach in and clean the inside of a corny and you can't do that with a Sanke. But there is nothing better for cleaning kegs than a keg washer, especially one that was used for fermentation. It sounds like you have Sanke couplers, so why buy pin lock or ball lock disconnects. Use this adapter and EVABarrier tubing to go from the Sanke coupler to the faucet shank. The smaller ID tubing is best for beer line and can be used for gas as well.

Good luck in your equipment quest.

 

[bwible]

Sanke kegs are a mystery to most homebrewers. They are not straightforward and nobody ever gave us any instructions. Unlike corny kegs which you can open and take apart and know where all the gaskets and fittings are. Sanke kegs require special tools to fill let alone disassemble and people have been injured removing the spear because they don’t know any better. Corny kegs are much cheaper for starters, and all around easier to work with, disassemble, clean, fill, etc, Sanke kegs are the tools of professional breweries who have such resources. Corny kegs are the less complicated tools of homebrewers,

 

[Climb]

Hmm. I will respect your desire to use corny kegs. I am not trying to convert anyone. I wanted to give the OP another option to consider since he likely is setup to use sankes already. However, I do take exception to most of your objections.

• I would say the whole brewing process is a mystery to the beginning home brewer, but we all figured it out.
• Many things in home brewing don’t come with instructions. That’s why You Tube and forums like this are so valuable.
• There are reasons why professionals use sanke kegs instead of corny kegs. Sankes have fewer parts, have fewer gaskets and are more reliable.
• A stem removal tool is nice to have, but not mandatory. I have gotten by for years with just two small bladed screw drivers.
• Any pressurized vessel can be dangerous if proper safety procedures are not followed. Home brewers use gas cylinders all the time.
• From what I have seen, sankes are less expensive than corny kegs on the used market and there are legitimate ways of obtaining them.

 

[sibelman]

No reason to belabor the Sanke vs Corny question, I guess. I followed the crowd in choosing ball lock cornies when I moved to kegging, and may not have realized I could probably fit 4 Sanke "D" kegs in my kegerator.

However, at least one reseller steers homebrewers away from their Sanke offerings.

The lack of a PRV would complicate things somewhat for me. But a widget like this would resolve that.

Then, there's economy to consider. Hmmm.