All symptoms
Diagnosis
FOAMY POUR
Glass arrives mostly head, beer never settles.
4
LIKELY CAUSES — RANKED MOST COMMON FIRST
- 1
BEER TOO WARM
Trunk line or keg above 38°F (3.3°C) lets CO₂ break out before the faucet.
Fix- Check keg cooler — target 36–38°F (2.2–3.3°C).
- Verify glycol bath is 28–30°F and lines are insulated.
- Let the system stabilize 30 min after any temp change before pouring.
- 2
CO₂ PRESSURE TOO HIGH
Applied pressure exceeds equilibrium for the beer's temp/volumes.
Fix- Look up the brewer's recommended volumes of CO₂ (usually 2.4–2.7).
- Use a Carbonation/Applied Pressure chart to set regulator.
- For most US lagers at 38°F: ~12–14 PSI on a short draw.
- 3
DIRTY OR SCRATCHED FAUCET
Beer stone and biofilm create nucleation points that throw foam.
Fix- Soak faucets in alkaline cleaner every 2 weeks.
- Replace faucets showing internal scratches or pitting.
- 4
LONG LINE TOO SHORT / WRONG RESTRICTION
Insufficient resistance lets CO₂ escape solution before the spout.
Fix- Calculate restriction: Applied PSI = (rise × 0.5) + (line resistance × length) + 1.
- Typical 3/16" vinyl ≈ 3 PSI/ft; 3/16" Bev-Seal ≈ 2.2 PSI/ft.
STILL NOT FIXED?
Capture temp at the faucet, applied PSI at the regulator, and a photo of the pour. Then check the spec reference or run a full line cleaning.