An insert that has a one-way valve that allows for one-way flow of liquid in response to reduced pressure. The insert is configured to be installed in a baby bottle to form two chambers—a reservoir chamber and a dispensing chamber. The insert also is provided with a valve failure mechanism which allows a user to force the one-way valve open in the absence of reduced pressure, which allows a user to prime the dispensing chamber (the nipple) prior to beginning feeding.
