A dispensing mechanism for an aerosol-generating article is provided, including an expandable buffering reservoir with an inlet and an outlet a dispensing reservoir of constant volume with an inlet and an outlet an inlet valve connected to the inlet of the expandable buffering reservoir and being configured to be connected to a liquid storage portion filled with pressurized liquid such that liquid can only flow from the liquid storage portion to the expandable buffering reservoir an outlet valve connecting the outlet of the expandable buffering reservoir to the inlet of the dispensing reservoir such that the liquid can only flow from the expandable buffering reservoir to the dispensing reservoir and a volume modifier configured to modify a volume of the expandable buffering reservoir.
