Clarified butter is milk fat rendered from butter to separate the milk solids and water from the butterfat. Typically, it is produced by melting butter and allowing the components to separate by density. The water evaporates, some solids float to the surface and are skimmed off, and the remainder of the milk solids sink to the bottom and are left behind when the butter fat (which would then be on top) is poured off.
Commercial methods of production also include direct evaporation, but may also be accomplished by decantation and centrifugation followed by vacuum drying; or direct from cream by breaking the emulsion followed by centrifugation.
Clarified butter has a higher smoke point (485 °F or 252 °C) than regular butter (325-375 °F or 163-190 °C), and is therefore preferred in some cooking applications, such as sautéing. Clarified butter also has a much longer shelf life than fresh butter. It has negligible amounts of lactose and casein and is, therefore, acceptable to most who have a lactose intolerance or milk allergy.