Methods for forming glass articles such as bottles and the like utilize pressurized flows of a cold blowing gas that is delivered from an insulated manifold into mold cavitites which are being used to mold glass articles. The cold blowing gas is a mixture of compressed cryogen vapor and ambient air that has been dehumidified, with the injection of the cryogen vapor into the ambient air being performed in stages, and utilizing a technique of cyclically operating and defrosting a plurality of cryogen injectors to assure a proper introduction of cryogen vapor and to prevent debilitating accumulations of ice about the cryogen inlets. The use of cryogen vapor in the blowing gas hastens cooling and solidification of newly formed glass articles so that the time during which the articles must be retained in their molds is significantly reduced. Reductions in mold retention times enable the apparatus to be operated at increased speeds, whereby its productivity is significantly increased. Productivity increases of 15 percent and often more can be achieved at relatively low expense. The use of cold cryogen vapor introduction into mold cavitites is applicable to a variety of glass molding techniques including press molding and blow molding.