To clarify butter

Put unsalted butter in a thick saucepan and melt over very low heat, skimming off any foam from the surface. The butter must not brown, but will become very clear with sediment sinking to the bottom of the pan. When foam stops rising to the surface, take off the heat and strain the fat through a double thickness of butter muslin or cheesecloth in a sieve. Leave any excess sediment or milky liquid at the bottom of the pan. Leave the butter to cool to lukewarm before using, and store any surplus in a covered jar in the refrigerator.