Abstract: A feeding bottle that includes a bottom surface that includes an axially disposed concave shaped portion that includes an air vent opening. An air vent assembly is securely disposed within the air vent opening to prevent air from leaking into the interior of the bottle or to prevent fluid from leaking out of the interior of the bottle using a closely fit connection that may include a beaded portion. The air vent assembly includes two resilient surfaces formed in a frustum shape having an upper surface. A valve opening is formed on the upper surface between the two resilient surfaces and is biased into a normally closed configuration. An air channel axially disposed within the air vent assembly and in communication with the valve opening, allows air to force the valve opening into an open configuration when the air pressure differential is greater than the bias force of the surfaces.