Method, machine and boiler for the preparation of beverages, in particular infusions such as coffee or tea; wherein the boiler has a central tank which delimits a superheating area for a liquid and an outer tank positioned around the central tank so as to delimit a heating area for the liquid and to allow the heating of the liquid in the heating area by means of the heat generated in the superheating area; the heating area having a first outlet for supplying hot liquid, the superheating area having a second outlet for the supply of steam.