A method for generating an insulating vacuum in a container is provided. The method includes evacuating air from a space between double walls of the container for a first predetermined time period. The method also includes after the first predetermined time period, if a vacuum level within the space has not reached a first predetermined vacuum level, purging the space by supplying a gas into the space and subsequently evacuating the air from the space for a period of time equal to the first predetermined time period. The method also includes repeating the evacuating and purging until the vacuum level within the space reaches the first predetermined vacuum level. The method also includes when the vacuum level within the space reaches the first predetermined vacuum level, evacuating the air from the space for a second predetermined time period.