Abstract: A refrigerant puck for insertion into an insulated beverage container holder. A portable beverage-filled container is inserted concentrically into the insulated holder such that a bottom surface of the beverage container contacts a top surface of the refrigerant puck which permits conductive heat transfer to occur, thus keeping the beverage container cool for an extended period while facilitating the consumption of a beverage therefrom. The refrigerant puck includes a disk-shaped container, preferably formed from a high-intensity polyurethane or polyethylene, which has a raised top surface that is substantially convex to mate with a concave bottom surface of the beverage container, thus ensuring a continuous and uniform contact with the majority of the bottom surface of the beverage-filled container which provides a direct cooling effect.