I have 4 kegs in a chest freezer that I control with an external temp controller, set to 3°C (37°F). They're hooked up to a 4-way manifold, then to a 6kg CO2 tank. I kegged a Red IPA on Wednesday afternoon, held it at 35psi for a couple of days, then returned it to 12psi. First couple of pours we're perfect, but by the 4th pour, 3/4 of the glass is foam, then when it settles the beer is quite flat. This is not the first time I've had this happen, but it doesn't happen with every beer which seems very odd to me. Any ideas what I'm doing wrong?
I've just now backed the pressure off to 10psi, not sure if that will help.
All of the beer lines are clean, I've got plenty of line on each keg (about 4m - inside diameter is 5mm. 13ft, 1/5") and all lines are resting above each keg.
I do not have a cooling fan going into my font, but I don't think that's the problem, as the level of foam does not reduce by the 2nd or 3rd pour in a row, as I would expect if the problem was warm beer in the lines.
I have faucets with flow control, but reducing the flow doesn't help.
I've noticed that despite all of the (corny) kegs being attached to the same manifold and CO2 tank, they pour at different rates - not sure what's going on there.
All kegs were bought 2nd hand, have new seals, and were holding pressure fine when I tested them at the time of purchase (6 months ago).
Any help is appreciated.
Sent from my iPhone using Tapatalk