536 COMPOSITION AND PROPERTIES OF BUTTER 



size of the fat globules gradually decreases and is smallest 

 shortly before the cows go dry. See also Chapter X on Churning. 

 The relative size of the fat globules exerts a marked in- 

 fluence on the mechanical firmness of the butterfat and butter, 

 and, therefore, on the moisture content of the resulting butter. 

 Butter made from relatively large fat globules is much softer, 

 churns much easier and more rapidly and contains more moist- 

 ure than butter made from relatively small globules. This is 



RELATIVE SIZE OF THE SMALLEST AND LARGEST GLOBULES OBSERVED 



Pig'. 84 



Volume .5236 cubic microns Volume 2758.32 cubic microns 



Diameter 1 micron Diameter 17.4 microns 



clearly shown by the results of Hunziker 1 , who, by centrifugal 

 separation, produced different lots of cream from the same milk, 

 containing average large globules (54.24 cubic microns) and 

 average small globules (20.72 cubic microns). Sixteen churnings 

 were made from each type of cream. The churning conditions, 

 as to temperature of cream, time held, amount of cream, richness 

 of cream, acidity of cream, etc., were the same for all churnings. 

 The results are shown in the following table : The small-globule 

 cream churned with difficulty, the butter required over twice 

 as much time to "break" as the large-globule cream, and it 

 formed round, hard, smooth granules, which did not pack read- 

 ily, and made a very firm and crumbly butter. The large-globule 



1 Hunziker, Mills and Spitzer, Purdue Bulletin 159, 1912. 



