A nozzle adaptable to the steam outlet of a coffee machine is designed to froth a liquid such as e.g. milk. Said nozzle comprises in the direction of the steam flow path: a steam inlet opening, a restriction with limited cross-section adapted to accelerate the velocity of the steam flow, and at least one cavity having a cross-section larger than the restriction and from which the frothed liquid can be drained. The nozzle further comprises an outer casing comprising a smoothening reservoir and a jet breaking surface facing the opening and at least one outlet opening radially offset relatively to the opening of the portion of the enlarged mixing cavity. The outer casing is arranged at least partially around the tubular portion of mixing cavity.