Guide
CO2 Regulator Settings: PSI by Temperature and Style
There is no single correct psi. The number depends on your temperature and your style, and here are both.
The short answer
At 38 degrees Fahrenheit, roughly 10 to 12 psi gives most ales their standard 2.4 volumes of CO2. Lower the pressure for stouts (around 8 psi) and raise it for wheat beers and saisons (14 psi or more). The same pressure at a warmer temperature under-carbonates, because CO2 solubility rises as temperature falls.
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The principle
Pressure only means something at a temperature
CO2 dissolves into beer, and how much dissolves at a given pressure depends on temperature. Cold beer holds more CO2 than warm beer at the same pressure. That is why there is no universally correct psi number, and why a figure quoted without a temperature is useless.
The unit brewers use is volumes of CO2 -- how many times the beer’s own volume in CO2 gas is dissolved in it. Target volumes by style:
Target carbonation by style
| Style | Volumes of CO2 | Approx psi at 38 F |
|---|---|---|
| British ale, stout, porter | 1.7 - 2.1 | 7 - 9 |
| American ale, IPA, pale ale | 2.2 - 2.6 | 10 - 12 |
| Lager, pilsner | 2.4 - 2.6 | 11 - 12 |
| Wheat beer, hefeweizen | 2.8 - 3.4 | 14 - 18 |
| Saison, Belgian ale | 2.8 - 3.2 | 14 - 16 |
| Nitro stout (beer gas) | ~1.2 plus nitrogen | Different system |
These are approximations rather than a chart to brew by -- published carbonation tables give exact figures for every temperature-and-pressure pair, and they are worth looking up for your specific setup. The shape of the relationship is what matters: colder means more CO2 dissolves at the same pressure, so the same psi at 45°F under-carbonates compared with 38°F.
The order of operations
Temperature, then pressure, then line
- Set and reach your serving temperature. Around 38°F for most beers. Let the keg actually get there -- a keg put in a cold cabinet two hours ago is not at 38°F yet.
- Set the pressure for that temperature and style. Use the table above as a starting point, then taste after a few days and adjust by a psi or two.
- Balance the line. If the temperature and pressure are right and it still foams, the line is too short. See below.
Line balancing
Why your pour foams at the right pressure
This is the part most guides omit. Beverage line has flow resistance, and the job of the line is to drop the keg’s pressure to approximately zero by the time the beer reaches the faucet. If the line is too short, the beer arrives still pressurized and breaks out of solution as foam the instant it hits atmosphere.
Resistance depends on internal diameter. Standard 3/16 inch beverage line has meaningfully more resistance per foot than 1/4 inch, which is why 3/16 is the homebrew default -- you need less of it.
- Serving at 10 to 12 psi through 3/16 inch line: you want several feet, typically more than a kit ships with. Many kits include a short line that is convenient and foams.
- Serving at higher pressure (a saison at 16 psi) needs proportionally more line.
- A jockey box has a very long coil, which is why it needs a higher serving pressure than a kegerator -- kegerator vs jockey box.
The practical approach: if the pour foams and the temperature and pressure are correct, add a foot of line and try again. Beverage line is cheap and this is a far better fix than dropping the serving pressure, which will leave the beer under-carbonated.
Troubleshooting
Four symptoms and their causes
Common pour problems
| Symptom | Most likely cause | Fix |
|---|---|---|
| All foam, correct pressure | Line too short, or beer too warm | Add line; check actual keg temperature |
| Flat beer | Leak, or not enough time at pressure | Leak test; wait 2-3 days |
| Over-carbonated, gassy | Pressure too high for temperature | Vent the keg, reset lower, wait |
| First pour foams, rest are fine | Tap tower holds warm beer | Fan in the tower, or through-door shank |
| CO2 emptying fast | Leak | Soapy water on every joint; check lid gasket |
| Sour or musty beer, keg tastes fine | Biofilm in the line | Full line clean cycle |
That last row is worth emphasizing, because it is the one people never suspect: beer lines grow biofilm and will sour everything passing through them within a few months of service. If the beer in the keg tastes right and the beer in the glass does not, clean the line.
What we recommend
The products on this page
What you set
Mid tier
Taprite Dual-Gauge CO2 Regulator
Taprite
A 0-60 psi output range with a dual gauge, so you can read what you set and see roughly when the cylinder is near empty.
Spec sheet
- Gauges
- Dual -- output pressure and tank contents
- Output range
- 0-60 psi
- Inlet
- CGA-320 CO2 tank thread
- Outlet
- 1/4 in MFL or barb
- Body
- Forged brass
- Serviceable
- Rebuild kits widely available
What it is not good at
One body means one pressure for all kegs downstream, which is the problem the next product solves.
Who it is for
Any single-keg or balanced multi-keg setup
If your styles differ
Prosumer tier
Secondary CO2 Regulator Manifold
Taprite / Duotight
Independently settable bodies. A stout at 8 psi and a saison at 14 psi simply cannot coexist on one regulator, and this is the fix.
Spec sheet
- Outputs
- 2, 3 or 4 bodies
- Adjustment
- Each body set independently
- Feed
- Runs off the primary regulator
- Gauges
- One per body on gauged versions
- Shutoff
- Per-body shutoff on most models
- Why
- Serve a stout at 8 psi beside a saison at 14
What it is not good at
An extra purchase and extra interior space in the cabinet.
Who it is for
Running a stout and a saison on the same gas
FAQ
Questions brewers actually ask
What psi should I set my CO2 regulator to?
At 38 degrees Fahrenheit, roughly 10 to 12 psi gives most ales their standard 2.4 volumes of CO2. Stouts and British ales want less, around 7 to 9 psi; wheat beers and saisons want 14 psi or more. The figure is meaningless without a temperature, because CO2 solubility rises as beer gets colder.
Should I disconnect the gas after carbonating a keg?
No. Leave the regulator connected at serving pressure for the life of the keg. Disconnecting means the beer slowly loses carbonation as you draw it down and the headspace grows, and you end up with the last few pints flat. The gas stays on at the pressure that maintains your target carbonation.
Why does my beer pour all foam at the correct pressure?
Usually because the beverage line is too short. The line's job is to drop keg pressure to roughly zero by the time beer reaches the faucet, and if it cannot, the beer arrives still pressurized and breaks out as foam. At 10 to 12 psi through 3/16 inch line you want several feet -- often more than a kit ships with. Add line rather than lowering the pressure.
What are volumes of CO2?
A measure of how much CO2 is dissolved in beer: one volume means the beer holds its own volume again in CO2 gas. Most American ales target 2.2 to 2.6 volumes, British ales and stouts 1.7 to 2.1, and wheat beers and saisons 2.8 or more. Converting a target volume into a regulator pressure requires knowing your serving temperature.
Can I serve two different beers at different pressures?
Only with a secondary regulator manifold. A single regulator sets one pressure for everything downstream, so a stout wanting 8 psi and a saison wanting 16 cannot coexist. A manifold with independently adjustable bodies gives each keg its own pressure and usually its own shutoff valve.
My beer tastes sour but the keg tastes fine. Why?
Biofilm in the beer line. Lines develop a microbial layer containing lactic and acetic acid bacteria within weeks of service, and it sours every beer passing through while the beer in the keg stays unaffected. A full alkaline cleaning cycle fixes it, and cleaning every two weeks of service prevents it recurring.
Read next
More on kegging
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The Best CO2 Regulators for Homebrew
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Guide
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Set-and-forget, shake and burst methods with real pressures and timings.
Guide
Homebrew Kegging Setup, Step by Step
The setup order, plus the three day-one failures and how to avoid them.
Roundup
The Best Beer Line Cleaning Kits
What to buy, how often to clean, and what grows if you do not.
Comparison
Kegerator vs Jockey Box
Chilling in storage against chilling in transit -- two different problems.
Roundup
The Best Kegerators for Homebrew
Kegerators compared on corny capacity, internal height and temperature range.