A device for carbonating a liquid (L) in a container (10) with a pressurized gas (G) comprises a receiving flask (20) for the container (10) and a filling head (30) which has means (31) for adding gas into said liquid in the container (10). The receiving flask (20) and the filling head (30) are movable in relation to each other between an insertion position (I) and a carbonating position (C). In the insertion position (I) the filling head (30) is spaced from the receiving flask (20). In the carbonating position, the receiving flask (20) and the filling head (30) are in contact with each other such as to form a substantially closed cavity (19). An interlocking connection directly connects the receiving flask (20) to the filling head (30).