Keg (Forced) Carbonation Calculator
Regulator pressure to force-carbonate a keg to your target CO2 volumes at any temperature.
Temperature in the keg
Ales 2.2–2.6, lagers 2.4–2.8
Set regulator to -
How it works
Force carbonation reaches equilibrium when the CO₂ dissolved in the beer balances the head pressure in the keg. For a target carbonation level at a given temperature there is exactly one regulator pressure that holds it - colder beer and lower targets both need less pressure.
PSI = f(temperature °F, target volumes)
standard carbonation-pressure polynomial
Sources: carbonation-pressure relationship as used by Brewer's Friend.
Set the regulator and let the cold keg sit a week or two to equilibrate. The number is the equilibrium serving pressure, not a faster "burst" pressure.
Frequently asked questions
- What CO₂ volumes should I target for my style?
- Typical targets are 2.2–2.6 for British and American ales, 2.4–2.8 for lagers, and 3.0+ for German wheat beers and Belgian styles. Cask ales sit lower (~1.5). Set the target here and it tells you the regulator pressure to hold.
- Why does colder beer need less pressure?
- CO₂ is far more soluble in cold liquid, so a cold keg absorbs the same volumes of gas at a lower pressure. Warm the keg and you must raise the pressure to hold the same carbonation - which is why force-carbing works best near serving temperature.
- How long does force carbonation take at set pressure?
- Setting the regulator to the pressure shown and leaving the keg cold for 7–14 days reaches equilibrium hands-off. Shaking or rocking the keg speeds it up but makes it easy to over-carbonate, so check often if you rush it.