bottle cap kind of loosing

[calman]

Hi,
I cap a bottle for the first time from my kegged beer. After capping, if I hold the bottle and twist the cap, the cap move or rotate a bit. I try the same with Heneiken and the cap does not move/rotate. Is it normal? How do I know if there is a leak?

Thanks.

 

[Lou]

How do I know if there is a leak?

turn it upside down. if liquid comes out of the bottle, there's a leak.

 

[Brewpastor]

They will often twist a bit.

 

[cweston]

My lifetime total for caps that didn't seal sufficiently is 1, so far.

I opened one, it was totally flat. So I just dumped it out and got another. It may have been a Bass or Warsteiner bottle: I know that I have some of both in my rotation, and I agree with whoever recently posted that they are harder to get a good seal on.