We make our own ice pucks. It's pretty simple. We make them with distilled water, because since we're a whiskey bar we don't want to put any mineralized water into our whiskey. So we use distilled water, we pour it into a silicone muffin pan and put it into our deep freezer. And they come out with a nice little hockey puck shape that fits perfectly in the bottom of rocks glasses. That way you can chill down your whiskey but without interrupting the flavor. The large [pucks], since it has less surface area than rocks do, dilutes the whiskey a little bit more slowly.
— Kat Szafraniec, Bedford Heights Lizardville beer and whiskey tech