A machine for making and dispensing liquid and/or semi-liquid food products includes a tank for containing the product, and a dispensing tap mounted on the discharging outlet of the tank. The tap has a duct connected to the discharging outlet and a piston sliding in a sealed fashion inside the duct. The duct has a first stretch extending between a first end and a branch of the duct from which a dispensing outlet of the tap extends, and a second stretch extending between the branch of the duct and a second end of the duct. The first end is connected in a sealed fashion to the discharging outlet and the second end is closed by a plug The piston is movable between a position preventing the dispensing of the product and allowing the washing of the duct, and a position allowing dispensing of the product.