Viski Glacier Ice Sphere Moulds Set of 4Viski Glacier Ice Sphere Moulds Set of 4 Crystal clear ice spheres chill faster, dilute less and last longer than cubes can. Fill the mould with water, freeze for at least 4 hours, and open to release a perfect ice ball a better way to savour liquor on the rocks. For added flavour and garnish, fill the molds with citrus fruit slices, and herbs or use juice in place of water.