Ventilation system and procedure for beverage containers

A ventilation system for a beverage container, the ventilation system comprising: a closure element (90, 91, 900) adapted and configured to be coupled to an open top of the beverage container (211), said closure element including closing (90, 91, 900) an air passage (806, 940) therethrough to allow the passage of air from the outside of the container (211) to the inside of the container and a one-way valve (10, 10 ', 1000) sealed and removably coupled to said closure element (90, 91, 900) and operatively connected to said air passage (806, 940), and extending towards said container (211), to allow passage of air from the outside from the container to said interior of the container and prevent the flow of liquid from the interior of the container (211) to the exterior of the container through said ventilation system, characterized in that said closure element (90, 91, 900) is a unitary element and includes: a central part that has an air passage through it, and at least one air vent tube (130) with several openings (135, 136, 140) of the air vent tube at a periphery of said closure element (90, 91 , 900), wherein the air vent tube (130) is operatively connected to said air passage (805, 940) such that air passes to the container (211) through the air vent tube , through the valve (10, 10 ', 1000) and to the container (211).