A liquid dispenser including a container that has an interior adapted to support a fluid. The liquid dispenser includes an air vent that is coupled to the container, and a balloon that is disposed in the container and in fluid communication with the air vent to provide fluid communication between the interior and an exterior of the container. The balloon is movable from an undeployed state to a deployed state in response to a pressure change between the interior and the exterior of the container. The balloon in the undeployed state is incapable of fluid communication between the interior and the exterior of the container, and the balloon in the deployed state has a position in which the balloon establishes fluid communication between the exterior of the container and the interior of the container.