A beverage held in a container is rapidly cooled by placing the container in a flexible sleeve defining a sleeve chamber that is cooled, either directly or by a secondary loop of heat transfer fluid, by a closed refrigeration circuit. An agitation assembly is selectively operable to oscillate the sleeve about a yaw axis. During active cooling, a cooled fluid (such as refrigerant or a secondary heat transfer fluid) flows through the sleeve chamber while the agitation assembly is simultaneously operated to rapidly cool the beverage held within the container.