Abstract: A method of preserving a perishable product placed in a container including attaching a flexible envelope including at least one protruding tab on at least a part of ends of the container to form an airtight casing for the products evacuating fluid contained in the casing by spreading at least one of the tabs to form a temporary passage between the interior and exterior of the casing, compressing or pressing the flexible envelope against the products and/or the container such that the fluid trapped in the casing is removed via the temporary passage, blocking the passage, and inserting at least one of the tabs inside the casing to form a communication conduit between the interior and the exterior of the casing; and a preservation device including a multiplicity of protruding tabs, at least one of the protruding tabs having a greater length than the other tabs.