Problems With Coopers Pet Bottles?

[hhouken]

Every brew has one or two bottles that empty themselves within a week of bottling. Has happened in fridge (held at 25C) and in pantry where temperature fluctuates 20C to 30C (bottles are stored on tiled floor so possibly some temperature stability there). FG always within bottling range & stable over two days. Sugar prime spot on. Not sure if temperature related (hot Brissie summers) or faulty bottles or caps. Bottles do not appear to require pressure release but I do it anyway afterwards.

 

[mwd]

Seems to be quite a common problem I have suffered it too. It is not the caps.

Here is a recent thread link to thread

 

[felten]

I've had a few bottles that leaked out of the base where the molding hole is, they weren't coopers though but the brewcraft ones, and it looked like they were from a dodgy batch. Luckily I caught them leaking while I was filling so I managed to decant them before it made too much of a mess.

 

[hhouken]

Thanks guys - had marked suspect bottles - 3 out of 75 to date - each had a little split at bottom. Did a test using 1/2 tsp bicarb and little vinegar and started bubbling out pretty soon