Packing or sealing products in an airless environment has long been an effective way to protect items and enhance shelf life. But most importantly vacuum sealing keeps good fresh.
Good quality vacuum bags are sealed on 3 sides and have multiple layers and satisfactory thickness to provide the maximum barrier to oxygen. It is this barrier to oxygen which will ultimately preserve the coffee and keep it fresh for longer. In addition, foil pouches or foil coated vacuum bags also keep the light out which goes further to protect the freshness of the coffee beans.