Burst Carbonation Calculator
Force-carbonate a keg faster: your serving pressure, the level a burst pressure reaches at equilibrium, and how to avoid over-carbonating.
Over-carbonation warning: a burst pressure is not a set-and-forget pressure. Left on too long the beer races past your target - an over-carbonated keg vents through the relief valve, pours all foam, and if you later bottle it the bottles can burst. Set a timer, then drop to the serving pressure above and taste before trusting it.
Commonly cited burst schedules (approximate)
| Approach | Rough setting | Then |
|---|---|---|
| Gentle burst | ~20–25 PSI, ~36–48 h | drop to serving PSI, taste |
| Standard burst | ~30 PSI, ~24 h | drop to serving PSI, taste |
| Fast burst | ~30–40 PSI, ~12 h | drop to serving PSI, taste early |
These are community rules of thumb, not a precise model - times shift with temperature, agitation and headspace. Always taste before serving.
How it works
Carbonation is governed by Henry's law: at a given temperature, each applied pressure has one equilibrium CO₂ level. This tool shows two of those exact figures - the pressure that holds your target long-term (your everyday serving pressure), and the level your chosen burst pressure would reach if you left it on indefinitely. Burst carbonation works by sitting between the two: you apply the high pressure briefly to load CO₂ fast, then back off to serving pressure before the beer reaches that high equilibrium.
On timing: the pressure figures are exact; the time to reach a given level is not a clean formula - it depends on temperature, agitation, headspace and keg geometry - so we deliberately do not compute a precise time. Use the schedule table as a starting point and taste.
serving PSI = −16.6999 − 0.0101059·T + 0.00116512·T² + 0.173354·T·V + 4.24267·V − 0.0684226·V² (T °F, V volumes)
equilibrium volumes at pressure P = (P + 14.695)(0.01821 + 0.090115·e^(−(T−32)/43.11)) − 0.003342
Sources: carbonation pressure/volume equations (Henry's-law fits) per Brewer's Friend and standard carbonation tables - the same equations used by our keg carbonation and CO₂ volumes tools. Burst schedules are widely-shared homebrew community rules of thumb, not a single published authority; treat the times as approximate.
Frequently asked questions
- What is burst carbonation?
- Burst (or "set-and-forget at high pressure") carbonation force-carbonates a keg faster by holding a pressure well above serving pressure for a short time, then dropping back to serving pressure. It is quicker than waiting a week at serving pressure, but you must reduce the pressure before the beer reaches equilibrium at that high setting - otherwise it over-carbonates.
- How long do I leave it at the burst pressure?
- There is no exact formula for the time - it depends on temperature, how cold the beer is, headspace, agitation and keg geometry. Commonly cited starting points are around 24 hours near 30 PSI, then taste. This tool deliberately does not invent a precise time; it shows you the pressure to serve at and the level a burst pressure would reach if left indefinitely, so you know what you are steering away from.
- Why does the calculator warn me so much?
- Because a burst pressure, left on too long, carbonates far past your target - and an over-carbonated keg vents through the relief valve or foams uncontrollably (and if you later bottle that beer, the bottles can burst). The safe move is to set a timer, then drop to serving pressure and taste.