96 DAIRY LABORATORY GUIDE 



EXERCISE 8 



INFLUENCE OF ACIDITY ON THE CHURNABILITY OF CREAM 



Object: To determine the influence of the acidity of the 

 cream upon the loss of butter-fat in the buttermilk, on the 

 overrun, and on the texture of the butter. 



Apparatus : Two lots of cream, sweet and sour ; churns ; 

 workers; scales; outfits for determining the percentage of 

 butter-fat, moisture, and salt. 



Steps: 1. Number the churns 1 to 3 and prepare for 

 churning. 



2. Weigh out definite amounts of sweet cream and sour 

 cream, after which weigh out a like quantity of sweet and 

 sour cream in equal parts. Retain samples of each lot to test 

 for acid and butter-fat. 



3. Temper each lot of cream to 54F. ; then put the sweet 

 cream into churn No. 1, the properly ripened cream into 

 churn No. 2, and the mixed cream into churn No. 3. 



4. Agitate the cream until the butter comes; then record 

 the length of time required to churn, after which remove the 

 buttermilk and retain samples to test. 



5. Temper the wash water to 56 F.; then wash, salt, 

 work, weigh, and pack each lot in the same way. 



6. Record the time required to churn, make all of the 

 tests for butter-fat, moisture, and salt; then figure the overrun 

 for each lot. 



7. Score the butter from each lot of cream after several 

 days and note the flavor and texture of each. 



Application: 1. How does the degree of acidity affect 

 the time of churning? 



2. In which lot was the greatest loss of butter-fat in the 

 buttermilk? Why? 



