the present invention provides an improved ice tray that forms narrow ice pieces that easily fit through the opening of portable beverage containers such as standard cans , bottles , and cartons , thereby saving the costs and energy associated with refrigeration . the ice tray has one or more narrow cavities for receiving water . a protrusion in the cavity produces a notch in the ice so that the ice may be broken into smaller pieces and conveniently dropped into the beverage containers . multiple ice trays may be stacked on top of each other .