Abstract: A method for heating containers having a product liquid therein utilizing the heat of condensation of a compressed refrigerant vapor. A first fluid medium is heated by transfer of heat from the compressed refrigerant vapor, thereby condensing the vapor to provide a liquid refrigerant useful for cooling. The containers are contacted with the heated fluid medium in the first stage of a container heating system having a plurality of stages, thereby transferring heat from the first medium to the containers. Thereafter the containers are contacted with a second fluid medium in a second stage of the system, the second medium entering the second stage at a temperature higher than the temperature at which the refrigerant vapor is condensed. The containers are heated in the system to a temperature above the dew point of the ambient air, thereby preventing condensation of moisture on the outside surfaces of the side walls of the containers leaving the system.

Abstract: A composite bottle for carbonated beverages comprising a bottle of CO.sub.2 -permeable synthetic resin having a cylindrical body, and a tubular CO.sub.2 -impermeable jacket covering at least a substantial portion of the body for reducing loss of beverage carbonation by CO.sub.2 permeation through the bottle.