a beverage container having an inner core and an outer shell , relatively rotatable such that a spiral groove in the inner core can be rotationally aligned with cooling flanges on the outside of the outer shell for cleaning , or rotated to close the cooling flanges , forming a cooling tube from the inside of the inner core to a drinking tube at the top of the container , thereby cooling a beverage that is drawn through the cooling flanges by radiating heat into the ambient environment .