Method for sealing a bottle (1), said procedure comprising the following steps: a) providing a cage (100), a closure cap (200) and a capsule (300), in which: - said cage (100) It is substantially cup-shaped and comprises a side wall (102) with i) an internal surface comprising an annular relief (120) in the vicinity of a free edge of the side wall (102) and ii) an external surface comprising a upper annular spoiler (109) and a lower annular spoiler (110), the upper annular spoiler (109) being in the vicinity of a closed base (101) of the cage (100) and the lower spoiler (110) being substantially opposite to the annular relief (120)； - said capsule (300) is cup-shaped and comprises a side wall (302) that ends at a free edge, said side wall (302) of the capsule (300) comprising an annular projection (310) that is configured to cooperate with the upper annular spoiler (109) of the cage during a final assembly stage, and an annular cavity (320)； - the internal surface of the side wall (102) of the cage (100) comprises an elastic retaining element (130) to retain the closure plug (200) in position； b) joining the cap (200) to the cage (100) and the cage (100) to the capsule (300), thereby obtaining a pre-assembled closure assembly (1000), said step comprising joining the cage (100) to the capsule (300) that the upper annular spoiler (109) is received in the annular cavity (320) so that the cage (100) is only partially inserted into the capsule (300)； c) align the preassembled seal assembly (1000) over the mouth of the bottle (1) and exert a pressure so that the bottle (1) is tightly closed, the preassembled assembly (1000) being adjusted over the bottle (1) so that the annular relief (120) presses elastically against a lateral surface (4b) of the neck of the bottle (4) and the annular relief (120) entering the cage (100) in contact with the lateral surface (4b) of the neck (4) of the bottle (1) before the cap (200) comes into contact with the bottle (1)； and d) exerting
