DAIRY FARMING DAIRYING. 



493 



The average water content of the worked butter from pasteurized cream 

 was 13.90 percent; from nonpasteurized cream 14.41' per cent (average 

 of 06 single experiments). The yield of butter per 100 lbs. of milk, as 

 found in the creameries, was but slightly diflerent when the cream was 

 pasteurized and when not pasteurized. As the average of 5 series of 

 experiments conducted on 2 different estates, the yields of butter from 

 pasteurized and from nonpasteurized cream were 3.524 and 3.532 lbs., 

 respectively — a difference of only 0.08 lb. of butter per 1,000 lbs. of milk. 

 The small deficit might be easily covered by working the pasteurized- 

 cream butter slightly less. 



Relation between the brine worked out and the decrease in water content 

 of butter. — The following formula is given by the author as showing 

 the relation of the amount of brine worked out and the water content 

 of the butter: If S be the yield of butter per 100 lbs. of milk, P the 

 water content of the butter, and Q that of the brine, and X the quan- 

 tity of brine which must be worked out to decrease the water in the 



SD 



butter 1 ) per cent, then X = 



I) 



Q — P + D- 



S 

 1, the formula will read X = 



By substituting Q = 80 and 



A table worked out on the 



81 — P- 



basis of this formula is given in the bulletin. 



Examination of butter fat. — Samples of butter fat produced on the 

 different feed rations were examined by various analytical methods, the 

 iodin number, saponification number, free fatty acids, volatile acids, 

 and refractive index being determined in each case. Experiments 

 showed that the amou'nt of free acids in the butter is greatly decreased 

 when the milk or the cream is heated previous to the churning; pasteur- 

 ization of the milk reduces the free fatty acid content of the fat more 

 than pasteurization of the cream. About half the acidity of fresh 

 sum -cream butter is due to free fatty acids in the butter, and the other 

 half to the acidity of the buttermilk remaining in the butter. 



The differences in the composition of butter fat from pasteurized and 

 from nonpasteurized cream are shown by the average data given in the 

 following table: 



Composition of butter from pasteurized and nonpasteurized cream. 



The pasteurization of the cream did not materially influence the iodin 

 number, refractive index, saponification number, or contents of volatile 

 acids in the butter fat, but the content of free fatty acids was appre- 

 ciably decreased by pasteurization. — F. w. woll. 



