Food preservation can include depositing dry ice and food within packaging. The packaging can include a flexible liner defining a wall aperture and an internal chamber. The internal chamber can receive the deposited dry ice and food and have an internal atmosphere. The packaging can include a check valve mounted to the flexible liner and covering the wall aperture. The check valve can be configured to occupy: (i) a closed state blocking fluid communication between the internal chamber and ambient via the wall aperture and (ii) an open state enabling fluid flow from the internal chamber, through the wall aperture, and into ambient.
