CHURNING 



285 



The locality largely determines the breed of dairy cows and 

 the feed; while the season has to do with the period, of lactation 

 and feed. 



Table 43. Showing Effect of Breed on Mechanical Firmness of 

 Butter and Relation of Mechanical Firmness to Butter Fat 



Constants. 1 



The above table shows that the fat from Holsteins and 

 Ayrshires contains a greater proportion of the softer fats (olein) 

 as expressed by the Iodine number and makes a much softer 

 butter than the fat from the Jerseys. In localities, therefore, 

 where the Holsteins and Ayrshires predominate, lower churning 

 temperatures should be used than in exclusive Jersey territory 



In the southern states where, because of the great availabili- 

 ty and cheapness, cottonseed meal is fed in relatively large 

 quantities, higher churning temperatures must be used than in 

 the northern sections where gluten feed and linseed meal are 

 a prominent part of the grain ration. In fact, in certain sections 

 of the South it is necessary to raise the churning temperature to 

 as high as 72 F. in order to complete the churning process in 

 a reasonable length of time and to secure butter with a body 

 sufficiently soft for proper handling. 



With reference to the season of the year the fact is well 

 known that in winter higher churning temperatures must be 

 used than in summer, in order to complete the churning pro- 

 cess without undue delay and to produce a butter that is not 

 too firm. The fat in winter milk is usually of a firmer character 

 than that of summer milk. 



That this condition is largely due to the change of the 

 chemical properties of the butterfat with the change of the 

 season, is shown in the following table which represents analyses 



1 Hunziker, Mills and Spitzer, Purdue Bulletin No. 159, 1912. 



