Consecutive spoilage in same keg

I've got a 3-tap kegerator and I've had one of the kegs ruin consecutive batches. 6 weeks ago I kegged a Tripel and a Pale Ale. The Pale Ale is great, but the Tripel spoiled. 1.5 weeks ago, I kegged a Wheat in the same keg as the Tripel and it spoiled.
I sanitize everything carefully with StarSan each batch. I soak the keg parts and beer lines in SS.
The Wheat was pressurized to 30psi to force carb, and the gas and beer lines were disconnected. 2 days later I had found that the CO2 had leaked out (but wouldnt the beer still be under a CO2 blanket?). I attached sanitized gas and beer lines and let it carb for a week. When I tried it a week later, I found it was spoiled.

The spoiled beer turns brown like a brown ale and has a slight smell and sickly sweet/acrid taste.


Any advice on how I can find the source of contamination and eliminate it?

It sounds like the keg isn't sealing and you got some lacto or pedio bacillus in the fridge that ruined those beers.

I'd guess that your keg isn't sealing properly and the beer is getting oxidized. Does it have a medicinal taste to it?

I cant tell if its medicinal. Definitely sweet.


Should I pressurize the empty keg and spray soap all over to look for a leak?

triangulum33 said:

The Wheat was pressurized to 30psi to force carb, and the gas and beer lines were disconnected. 2 days later I had found that the CO2 had leaked out

Click to expand...

you're disconnecting the gas to force carb? admittedly i'm a novice when it comes to kegging, but perhaps after that initial 30psi of gas is absorbed into the liquid the remaining pressure isn't enough to keep a tight seal on the lid?

Have you replaced O rings? (unlikely source of the problem).

Do you have a plastic gas diptube that could have an infection in it?

Could the CO2 line leading to that keg have possibly sucked up some beer in the past, and now have a nice little infection in it that's spraying into each new keg you connect?

Thanks Shorty. I dont have a plastic diptube, and I did disassemble the ball locks, o-rings and diptubes to sanitize.
I will check the CO2 line and o-ring seal, though.