The invention relates to a receptacle device (1) for separating a mixture (2) into a lighter phase (3) and a heavier phase (4), which comprises a receptacle (5) having an open end (7) and an end (8) closed by a base (9), and the open end (7) is closed by a removable closure unit (15). A separating element (14) made of an elastically deformable material is arranged in a receptacle chamber (13), and the separating element (14) in its non-deformed initial state has a spherical shape and is arranged in the region of the base (9) and contacts an internal face (11) of a side wall (10) in a contact plane (23) oriented perpendicular to a longitudinal axis (6). An external diameter (24) of the separating element (14) is selected to be larger in the non-deformed initial state thereof than a cross-sectional dimension (25) of the receptacle chamber (13) in the contact plane (23). The separating element (14) is held positioned on the internal face (11) of the side wall (10) in a pre-tensioned standby position. The invention further relates to a method for providing a receptacle device (1) of this type and a method for separating a mixture (2) into a lighter phase (3) and a heavier phase (4).