Beverage dispenser with powder container

Method for preparing a beverage with a dispenser comprising

• at least one container for storing soluble beverage powder, the container comprising a tank, a discharge port at the outlet of the tank, a dosing device configured for displacing a dose of soluble beverage powder to the discharge port, at least one beverage preparation unit operatively linked to the container for preparing a beverage from the stored soluble beverage powder, the discharge port of the container comprises an internal delivery tube comprising a hollowing-out in its bottom part and closed at its end next to the hollowing-out, an external movable cover covering at least a part of the internal delivery tube and comprising a hollowing-out in its bottom part, the external movable cover being movable according to a translation movement between a dosing position in which both hollowing-outs of the internal delivery tube and of the external movable cover overlap each other, and a rest position in which the surface of the external movable cover overlaps and closes the hollowing-out of the delivery tube, the dispenser comprises an actuator able to exert a force on the external movable cover so as to move it between the rest position and the dosing position, the actuator comprising two rods, and each of the rod is configured for engaging at its one first end a lateral side of the external movable cover, and each rod extends along the lateral side of the tank, and each rod is configured for being engageable at its one second end by a motorised actuator to create a translation movement of the rod comprising the steps of:
• a) activating the dosing device deliver a dose of beverage powder through the discharge port of the tank inside the beverage preparation unit;
• b) preparing the beverage inside the beverage preparation unit by mixing the dose of beverage powder with a diluent;
• wherein during step b) of beverage preparation the surface of the external movable cover of the discharge port overlaps and closes the hollowing-out of the delivery tube of the discharge port.