Homes, restaurants, and businesses rely on clear, clean ice for many applications. Ice is considered a food source, and the water that makes the ice must be of good quality. Good quality water will produce a crystal-clear, hard piece of ice.
Ice hardness is a measure of the thermal cooling capacity (Btus) of the ice. Ice hardness is measured as a percentage. Flake ice falls in the 75 percent hardness range where block ice falls in the 95 to 100 percent hardness range depending on the quality of water making the ice and how the ice is made. The higher the percent of hardness, the more cooling ability or cooling capacity the piece of ice will have. This occurs because hard ice is denser than soft ice. Harder ice will last longer in a glass when cooling a drink or in a cooler cooling food.