Dodgy keg?

[Eskimo John]

Since the beginning of December I have brewed six times.
Two of these brews have gone sour, both Wheat beers and both in the keg and in the same keg when gone bad. All of the other brews are just fine.
After the first failure I took the keg apart to find out why I seemed to have had an issue and found some old hop debris in the out valve. Cleaned and sterilised, I rebrewed and I have had the same problem. So perhaps I haven't got to the bottom of the problem.
The keg seems to hold gas pressure although carbonation hasn't been as good as I might expect so I am wondering if I have an issue with the keg. Perhaps a slow leak or something like that.
Having said that I would have thought the co2 sitting on top of the beer might protect it even at low pressure.
Has anyone had any keg issues like this?

 

[Sandimas]

What type of keg?

If a plastic one then yes. I tried for 18months to get rid of it, really deep clean, bleach, the lot, but my beer still got ruined in it. Moved over to stainless-steel and not looked back, I've dumped all my plastic kegs, and so have others I know. They were fine to start with.

 

[Eskimo John]

Sorry I should have said. It a stainless steel corny keg

 

[-Bezza-]

I can't see a leak causing that. You'd notice a leak because the co2 bottle would empty. Even if you turn the co2 off, you're unlikely to get any ingress of anything.

I'm wondering if it was the wheat itself. Was it the same batch of wheat?

Guess to start the elimination process it would be helpful to understand what was the same and what was different between the two sour brews.

Also, what was the full recipe and brew process?

 

[Eskimo John]

Some of the same batch of wheat for sure. I will post the recipe later but I won't be using the same one again in any event.

 

[Sandimas]

If you struggle to pin it down, bottle a few from subsequent brews, then you have something to check against the keg to determine if it's the keg or your actual brew. I did this when I started having problems, the bottles were fine whereas the keg wasn't, so nothing wrong with the brew itself, the keg was the problem.

 

[The Baron]

Always a pain things like this. I think we have all done this head scratching, going through our process bit by bit and insist we have then somebody shines alight and its sorted.
Anyway good luck because until you find it it will p!ss you off