PSI Tolerance of Grolsch Bottles

[Beaudoin]

Hello everyone.

I just wanted to let you know that I contacted Grolsch directly and asked them what the PSI rating was on their flip-top bottles, and they replied in a day!! I thought I'd share this information as it could be useful to other brewers:

"New flip-top bottles are suitable to reach a minimum [sic - she meant maximum] of 290 PSI (= 20 bar) internal pressure before bursting.
Filled flip-top bottles are suitable to reach about 70 to 80 PSI (= 5 to 6 bar) internal pressure before blowing off (lifting the closure to release pressure).
Under normal circumstances in for example a supermarket (temp 20 degrees Celsius) the internal pressure in the flip-top bottle is about 20 PSI (= 1.4 bar)."

 

[timsch]

How does that compare to standard 12 oz bottles, I wonder?

I have some original green grolsch bottles I bought used that have not been nearly as strong as the EZ bottles I bought from my LHB store. I've had at least a half-dozen burst, all breaking out the bottom. I just lost another one tonight as I was putting it in the fridge. These had been bottled for about three months now, so I was pretty surprised (and mad....) I've mixed bottles with each batch and it is only the green grolsch bottles that break.

I am not familiar with any blow-off feature that you mention. There is no pressure release that I see on my bottles.

All opinions seem to be that these bottles are very strong, but that has definitely not been my experience. I cry rivers of wasted beer....

 

[Beaudoin]

I'm sorry to hear that timsch. I got this directly from Grolsch themselves.

It could be that these ratings are based on brand new bottles (as they do say new). It could be that old ones get micro cracks in them and as they age and get beat up, maybe they get more brittle. Not sure.

 

[GilSwillBasementBrews]

How does that compare to standard 12 oz bottles, I wonder?

I have some original green grolsch bottles I bought used that have not been nearly as strong as the EZ bottles I bought from my LHB store. I've had at least a half-dozen burst, all breaking out the bottom. I just lost another one tonight as I was putting it in the fridge. These had been bottled for about three months now, so I was pretty surprised (and mad....) I've mixed bottles with each batch and it is only the green grolsch bottles that break.

I am not familiar with any blow-off feature that you mention. There is no pressure release that I see on my bottles.

All opinions seem to be that these bottles are very strong, but that has definitely not been my experience. I cry rivers of wasted beer....

He was just saying if the pressure builds too much it will lift the cap slightly and release pressure until its at a manageable level for the cap to contain.