Cut unsalted butter into 1 -inch pieces. In a heavy saucepan melt the butter over low heat. Remove the pan from the heat, let the butter stand for 3 minutes, and skim the froth Strain the butter through a sieve lined with a double thickness of rinsed and squeezed cheesecloth into a bowl, leaving the milky solids in the bottom of the pan. Pour the clarified butter into a jar or crock and store it, covered, in the refrigerator. The butter keeps, covered and chilled, indefinitely. When clarified, butter loses about one fourth of its original volume.