ISS 



Testing Milk and Its Products. 



same proportion of fat contained in the milk is re- 

 covered in the butter in different ehurnings, but since 

 the water and salt in butter are held mechanically and 

 are not chemically combined with it, the amounts re- 

 tained by the butter are quite variable in different 

 ehurnings. 



213. Variations in the composition of butter. As 

 an illustration of the variations in the composition of 

 butter that usually occur, the analyses made in the 

 breed tests at the World's Fair in 1893 may be here 

 cited; the butter was in all cases made by as nearly 

 identical methods and under as uniform conditions as 

 could possibly be obtained by the skilled operators hav- 

 ing this work in charge ; the average composition of 350 

 samples of this butter, with upper and lower limits, 

 was as shown in the following table: 



Composition of samples of hutter, World's Fair, 1893. 



Average of 350 

 analyses 



Lower and ud- 

 per limits 



Water 



Per cent. 



11.57 



8.63-15.00 



Fat 



Per cent . 



84.70 



76.53-88.26 



Curd 



Per cent. 

 .95 



.50-2.14 



Salt and 

 ash 



Per cent. 



2.78 



1.01-8.58 



Sum of 



water, curd, 



salt and 



ash 



Per cent. 

 15.30 



Analyses of fifty samples of creamery butter taken in 

 1896, from the tubs ready for market at as many Wis- 

 consin creameries, showed that no two of them were ex- 

 actly alike in composition, but varied within the limits 

 given on the following page •} 



> Wisconsin experiment Btatlon, bull. 56. 



