10 ANALYSIS AND ADULTERATIONS OF BUTTER. 



as to give rise to the so-called cheesiness. The less casein a 

 butter contains the better, since this substance, like all other 

 albuminous matters, is apt to decompose to induce decom- 

 position of the bodies with which it may come into contact, 

 and to hasten that splitting-up which takes place in pure 

 butter when exposed to the air. The keeping properties of a 

 butter are therefore dependent, in some measure, upon the 

 amount of casein present. An excess of casein renders 

 necessary an excess of salt to counteract the pernicious 

 influence of the nitrogenous matter ; consequently a careless 

 or fraudulent manufacturer gets the benefit of the increase of 

 weight by both substances. 



IV. Salt. Our experience teaches us that butter contains 

 on an average 2 -5 per cent, of salt. Butter is spoken of as 

 either fresh or salt butter. This distinction is convenient for 

 commercial purposes, but would be a useless introduction in 

 this book, as no defined line can be drawn between the two ; 

 to each salt has been added, whether it be a so-called 

 fresh or salt butter. 



Hassall found the salt, in one instance, as high as 28 '6 per 

 cent. Wanklyn's fifty analyses give a range of from 0*1 to 

 107 per cent. We think that the amount of salt in any 

 butter should never exceed 8 per cent. An excess of salt is 

 commonly accompanied by an excess of water, and frequently 

 by an excess of curd ; it would not be practical to use salt 

 alone as an adulterant, since it is so easily detected by the 

 taste, and therefore reduces the commercial value to a greater 

 extent than it increases the weight of the butter. 



To sum up. The amount of water in butter should not 

 be higher than 12 per cent., the curd and the salt should be 

 about 2-5 per cent., the latter may rise as high as 8 per cent. 

 The fat, which averages at about 87 or 85 per cent., should 

 not fall in any case below 80 per cent. 



