Packaging for liquid food, where the packaging has an outer casing (2) of cardboard, an inner bag (8) of plastic foil which consists of e.g. completely recyclable bio-polyethylene plastic, where the inner bag is arranged inside the outer casing (2) and completely fills it when the inner bag is filled with the food, and an opening module, here called MF module (12), which contains an emptying device and a filling device arranged on a plastic disc (14), wherein the emptying device comprises an emptying channel (13) and a stopper (19) and where the filling device comprises a filling channel (25) and a filling plug (26) and wherein the MF module (12) is connected to the inner bag (8) by that the underside of the plastic disc (14) is welded to the outside of the inner bag so that the emptying channel (13) connected to a hole (11) in the inner bag (8) where the filling channel (25) opens into the emptying channel (13) is connected to the outer cover (2) in that top flaps (6a-6d) of the outer casing are attached to a slot (17) in the plastic disc (14) along the side edges thereof. The application also includes a method for filling the packaging and a method for producing an inner bag for the packaging.