COMPOSITION AND PROPERTIES OF BUTTER 531 



ferent churnings of butter from California, Iowa, Michigan, 

 Minnesota, North Dakota, Pennsylvania, Texas and Wisconsin, 

 and found the maximum, minimum and average percentages of 

 butterfat, water, salt and curd to range as follows : 



Table 71. Maximum, Minimum and Average Percentages of 

 Butterfat, Water, Salt and Curd 1 in American Creamery Butter. 



Butter. 



695 Samples of Butter Fat Water Salt Curd 



Average 82.41 13.90 2.51 U8 



Maximum 87.39 20.65 5.98 3.42 



Minimum 73.49 10.13 .68 .12 



A study of these figures shows a most unusual range be- 

 tween maximum and minimum percentages of the several butter 

 constituents, while the average percentage appears quite normal. 

 The wide range of percentage composition may be due in part, 

 at least, to the fact that over two-thirds of the samples an- 

 alyzed represent butter from the very heart of the co-operative 

 and small local creamery, the states of Minnesota, Wisconsin 

 and Iowa. The average buttermaker in these creameries is 

 more of an all around creameryman than an expert buttermaker. 

 His knowledge of the art and science of moisture control is 

 limited and the percentage composition of his butter is prone to 

 lack in uniformity. 



Analyses of butter from the larger creameries, whose butter- 

 makers are strictly churnmen, and whose skill in moisture con- 

 trol is more highly developed, would undoubtedly show a much 

 more uniform percentage composition, with a slightly higher 

 average water and salt content and a slightly lower fat and curd 

 content. 



The Butterfat. The butterfat is the chief constituent of 

 butter. It normally varies between about 80 and 85 per cent, 

 averaging about 82^ per cent. Abnormal cases occasionally 

 show variations within much wider limits. In rare cases butter 

 has been found to contain as high as 90 per cent fat and as low 

 as 72 per cent fat. 



1 The term "curd" as used here includes, in addition to the nitrogenous 

 constituents, the ash and lactose. 



