A packaged aqueous carbonated beverage comprising a container which replaces at least a portion of CO.sub.2 that permeates through the container or closure. The container comprises a polyester composition including a polyester suitable for packaging aqueous carbonated beverages and a carbonating agent. The aqueous carbonated beverage is disposed in the container such that the aqueous carbonated beverage has direct contact with the container and a closure seals the beverage in the container. The carbonating agent reacts with water in the carbonated beverage forming CO.sub.2 for replacing at least a portion of CO.sub.2 that permeates through the container or closure. A corresponding method of packaging an aqueous carbonated beverage is disclosed.