Fat may be obtained from mammal’s milk, and was traditionally used by the people who kept cattle herds. It is obtained from milk fat by churning it, a mechanical process which involves heavy mixing at cool temperatures, and results in the separation of a yellowish watery emulsion containing some protein which is called buttermilk and the creation of an emulsion the continuous phase of which is lipidic. This emulsion contains aproximately twenty percent water and exhibits a plastic behaviour at room temperature, but becomes less and less spreadable as crystals of triacylglycerol grow when temperature is lowered.

Butter is an important source of energy in the diet. A yellow (carotenoid) spread it may and often contains added salt which acts not only as a flavour enhancer but also as an antimicrobial.

A relatively high valued spread, butter was the target of the first successfull man-made copy, and margarine has indeed succeeded in replacing it in may applications.

Butteroil is obtained by heating butter and allowing for gravity separation of the oil phase. Butteroil is nowadays the internationally traded commodity because of transportation costs and because of its increased stability to oxidation. Its conversion to butter may then be easily achieved, the final composition made to match local pReferences.