PART II BUTTER 



INTRODUCTORY. 



WHEN the majority of the fat is removed from milk by 

 skimming or separating, the latter method now being the 

 most usual, and the resulting cream subjected to powerful 

 mechanical treatment, as in churning, the milk fat passes from 

 its fluid, under-cooled state into a solid substance. The fat- 

 globules are thereby formed into grains which are visible to the 

 naked eye, and in size are about as big as the head of a pin. 

 By washing and working the mass of impure butter, the greater 

 part of the butter-milk is got from it, and the substance known 

 as butter is left. 



Butter can be made from either sweet or sour cream. In 

 the first case, the cream, directly after separating, is taken and 

 made into butter, whilst in the second case the cream is allowed 

 to sour, either by adding sour butter-milk or by means of a pure 

 culture of lactic acid bacteria. Then the cream is left at the 

 temperature of the room for about eighteen hours to allow of 

 lactic acid fermentation taking place and the proper degree of 

 ripening being reached, after which the cream is churned. Both 

 kinds of butter can be made from pasteurised cream, and in 

 this way a butter with better keeping qualities is obtained. 



Generally a larger or a smaller quantity of salt is worked into 

 the butter, the amount varying between 1 per cent, and 5 per 

 cent., according to the length of time it is desired to keep it. 

 In certain districts, however, butter is not salted at all. 



A good sample of normal butter has the appearance of a 

 more or less yellow, soft, and plastic mass with a dull surface. 

 The plasticity of the butter, which differs from that of any 

 other fat, is due partly to the variety of glycerides present in 

 the butter and their relations to one another. Butter ought to 

 have a fresh, aromatic smell and taste, and the brine should be 

 perfectly clear, like water. 



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