Carbonation Volumes and Head Pressure
Computes volumes of CO2 from head pressure and beer temperature, and the pressure for a target, both ways.
Example
You enter
- Beer temperature (deg F) 38
- Head pressure (psig) 12
- Target carbonation (volumes) 2.6
- Warmer temperature to compare (deg F) 45
You get
- Carbonation at the gauge 2.576 volumes at 12.0 psig
- Pressure for the target 12.25 psig for 2.60 volumes
- Same gauge, warmer beer 2.26203
- Pressure to hold the target warm 15.98 psig -- 30% more
- Then fix the cooler, not the gas 2.96 volumes -- over-carbonated
Checked against published worked examples from: Brewers Association.
Details, formula, and sources
ScopeThe worked brite tank at 38 degF and 12 psig holds 2.58 volumes. Let it drift to 45 degF and it falls to 2.26 with the gauge unmoved; the 16.0 psig that restores it over-carbonates to 2.96 once the cooler is fixed.
Formula or tablevolumes = (psig + 14.695) x k(T) - 0.003342, with k(T) = 0.01821 + 0.09011 e^(-(T - 32) / 43.11), T in degF; solved both ways.
Source and editionA fit to the published CO2 solubility tables at sea level. The brewery's own dissolved-CO2 measurement governs.
Free accessThe solubility tables are published openly.
What governsEstimate. AHJ and licensed professional govern.
API field namesbeer_temp_f, gauge_psig, target_volumes, warm_temp_f, co2_volumes, pressure_for_target_psig, warm_co2_volumes, warm_pressure_for_target_psig, overcarbonation_volumes
- Altitude sea-level atmosphere; altitude lowers itfit basis
- Range 28 to 80 degFfit range