A vent system for a liquid container having a container body with a top dispensing opening and a bottom portion having coupling elements and a bottom opening, the vent system including a solid closure member for closing the bottom opening; a sealing member disposed in the closure member, the sealing member including a sealing element configured to seal a rim of the container bottom opening and having a bore, and a one-way valve sealing the bore against liquid passage from the container and selectively permitting air passage through the bore into the container; complementary coupling elements on the closure member for coupling to the coupling elements on the bottom portion of the container, configured so that ambient air can enter between the container body and the closure member; and an air conduit extending from the coupling elements to a space in the vent system which is in operative communication with the bore, and a method for making it.