Vacuum Pouches Vacuum packing is a method of storing and preserving food in an airless environment, usually in air-tight pouches to prevent the growth of micro-organisms. Tangible advantages can be gained in the kitchen through vacuum packing, such as products being stored for several days longer without any deterioration in quality. The control of "air content" in retortable pouches must be defined as a critical process factor by the processor, if it will affect the scheduled thermal process. This is specified in the scheduled process as being the residual gas. The product type will determine whether a vacuum sealer should be used.