A dispensing tap for liquids includes a body connected to the neck of a container, a dispensing head with an outlet or mouth, and a throat connecting the body to the dispensing head. A shut off valve is configured for sealing engagement with the mouth of the dispensing head, and a piston is axially guided within the dispensing head. The piston includes a peripheral seal slidably engaged with an interior surface of the dispensing head, and a valve stem coupled to the shut off valve. The piston is selectively actuable between a normally closed position an open position. A spring is captured between the piston and the dispensing head normally biasing the piston and shut off valve to the closed position. A vent is in communication with an interior of the body and the vent is opened and closed with movement of the piston and shut off valve.