Great drinks should not be watered down, although a splash of water can activate and enhance the spirit’s flavor. Ice melts at a rate proportional to its surface area. That means multiple small ice cubes will melt very rapidly, watering down your drink quickly. A sphere, on the other hand, has less surface area than a cube of similar dimensions. A single large ice sphere provides a very slow melting rate, activating the aromatics in your drink without watering it down.