Abstract: A device for heating and emulsifying milk, especially to prepare a white coffee drink known as "cappuccino" with the assistance of a steam jet, which has a vacuum chamber surrounding a nozzle and formed with an emulsion discharge port, a passageway for admitting sucked-in air, and at least one passageway for the milk which enters the chamber on account of the negative pressure prevailing therein, thereby milk, air, and steam are mixed together in said chamber and then made to flow out through said discharge port.