Sixty Percent Foam on One Tap

Order them cheapest and most reversible first, and never adjust the manifold until you've ruled out the glass - because the manifold feeds 19 working taps.

1. Glassware (30 seconds, free). Pour the same beer into a room-temperature glass that has been hand-rinsed in clean water. Frozen glass plus recently topped-up rinse aid is a textbook nucleation pair: chill creates condensation and a rough surface, and a detergent film gives CO2 thousands of places to break out. If the same tap pours a normal pint into that glass, you're done - the beer and the system were never the problem.

2. Dispense hardware on tap 12 only (5 minutes). Something local to one tap, since 19 others are fine: a worn or mis-seated faucet seal, a partially open faucet, a kinked or coiled line behind the manifold, a bent shank. Look at the line itself - visible bubbles mean CO2 is breaking out in the line, which points at temperature or pressure on that run.

3. The keg (last). Swap the keg onto a known-good tap, or draw a sample through a jumper. Also ask whether the keg arrived warm and was shaken straight into the cooler - two days is enough to chill, not always enough to settle.

The order stops you from "fixing" a balanced system because of a dirty glass, which is the most common version of this call.

Do the rough balance math before blaming the gauge.

• Line restriction: 3/16-inch vinyl runs roughly 2-3 psi per foot, so 5 ft is about 10-15 psi of restriction.
• Lift: about 0.5 psi per foot of rise, so 4 ft adds roughly 2 psi.
• Total needed: roughly 12-17 psi to push beer at a reasonable flow with a stable pour.

At 15 psi applied, the system is inside that window - not obviously broken. That matches the symptom pattern: 19 other taps on the same manifold pour fine, so the regulator and manifold are almost certainly delivering what they claim.

So pressure is not the first suspect. The remaining explanations are the ones that produce foam without a balance error:

• Carbonation mismatch. At 38°F and 15 psi, equilibrium sits around 2.7 volumes of CO2. If the brewery carbonated this cream ale higher than that, CO2 will break out of solution in the line and at the faucet no matter how slowly you open it. The fix is to bleed the keg down and let it re-equilibrate - not to crank the manifold, which would wreck 19 other pours.
• Warm tower. An unrefrigerated tower with a 4-ft rise means a slug of warm beer in the line; that explains a foamy first pour, but not every pour.

If it does turn out to be the keg, keep the correction local: vent it, let it settle in the cooler, retest.

Right now, at the bar:

• Never serve the 60%-foam glass, and never top it off with beer from another tap - the guest paid for a pint, not a glass of foam over a flat beer.
• Pour into a room-temperature, hand-rinsed glass; open the faucet fully (a half-open faucet is its own foam generator) and hold the glass at about 45 degrees, straightening as the head forms.
• If the tower line is warm, draw and discard a few ounces until the pour runs cold and clean.
• Then hand over a correct pint, say plainly what happened ("chilled glass, my fault, here's a proper pour"), and comp it. The explanation costs nothing; the mystery costs trust.

Tomorrow's shift:

• Out of the freezer. Stop stocking glasses frozen. Chilled glass is a foam problem dressed up as hospitality, and it also mutes aroma.
• Rinse aid audit. Check the dosing and run glasses through a clean-water rinse; if they're coming out warm with a film, that's two nucleation sources on one glass.
• Ticket tap 12 for a faucet seal and line inspection, and log the vent-and-settle if the keg was over-carbonated.
• Log the whole thing - date, tap, symptom, tests, outcome - so the next person doesn't start over, and so the pattern shows up if the same tap keeps doing it.