An internal pressure-dependent characteristic (internal pressure characteristic) is measured for containers. When the closures are applied to the containers, the internal pressure characteristic or parameters relating to the closures or containers required for the measurement of said internal pressure-dependent characteristic is detected. The containers are marked, at the very latest when said closures are applied, whereby said marking enables the values detected during the application of said closures to be allocated to the corresponding containers. The internal pressure of the container is determined on the basis of the value of the internal pressure characteristic measured after a certain amount of time has elapsed since the closures were applied and by comparison with the internal pressure characteristic measured during the application of the closure, taking into account the parameters thus detected.