A bladeless mixer for mixing a liquid, includes a cylindrical or truncated cone-shaped receptacle having an axis A and a radius R, the radius R being the shortest distance between the axis A and a side wall of the receptacle, the liquid to be mixed being placed in the receptacle and having an exposed surface at a height H measured along axis A; a member for tilting the receptacle such that axis A forms a non-zero-degree angle of up to 30° relative to the vertical direction; a member for imparting a rotational movement to the receptacle along axis A at an angular speed of rotation Ω; wherein the aspect ratio H/R of the height H to the radius R and the angular speed of rotation Ω are selected such that an inherent mode of inertia of the liquid has an unstable resonance when the receptacle is tilted and rotates.