A bottle assembly has an open ended container and a vent assembly positionable at least in part on the rim of the container to permit venting of the container during use. The vent assembly generally comprises a vent insert and a receptacle portion releasably connectable to the vent insert. The vent insert includes an annular lip depending longitudinally within the container upon positioning of the vent assembly on the rim of the container. The annular lip has a transversely inner surface having one of a catch and a latch.
