202 Testing Milk and Its Products. 



Questions. 



1. What is the average composition of American creamery 

 butter, and between what extremes does the composition of butter 

 vary? 



2. What is the difference between the churn yield and the re- 

 sults obtained by the Babcock test? 



3. What does the overrun represent? 



4. Mention several factors that cause a large overrun. 



5. Give an illustration of how the per cent, of increase of 

 churn over test is found, and how the overrun is calculated. 



G. Show by an example that butter containing S0% fat can- 

 not give an overrun of more than 25%. 



7. How many pounds of butter containing 80% fat can be 

 made from 100 lbs. fat? 



8. Why is the overrun from cream greater than from milk? 



9. What is the overrun when 70.5 lbs. of butter are made 

 from 140 lbs. of milk, testing 3.15 per cent? 



10. What is the overrun in each of the following cases V 



220 lbs. butter from 8000 lbs. milk, testing 2.3% fat. 

 250 lbs. butter from 4000 lbs. milk, testing 5.8% fat. 

 600 lbs. butter from 2000 lbs. cream, testing 25.0% fat. 

 480 lbs. butter from 1000 lbs. cream, testing 40.0% fat. 



11. How much butter containing (a) 80% fat, and (b) 82.5% 

 fat can be made from 3250 lbs. milk, testing 4.3% fat, assum- 

 ing that the skim milk is 80% of the whole milk and contains 

 0.1% fat, and the butter milk, which is the cream minus the fat, 

 contains 0.25% fat? What is the overrun in each case? 



12. How much butter is obtained from 5800 lbs. milk, testing 

 3.7% fat, when the overrun is (a) 12.5% and (b) 16%? 



13. Two cows in full milk produce, one 17.5 lbs. of milk a day, 

 containing 4.35% fat; the other, 27.3 lbs. of milk, testing 3.4%. 

 If the milk of both is made into butter or cheese, how much 

 butter or cheese may be expected from each one in a week? 



14. What is a fair percentage of loss of fat by waste other 

 than in skim milk and butter milk under average creamery con- 

 ditions in case of milk and cream? 



15. How much butter may be made from (a) 15,640 lbs. milk, 

 testing 3.8% fat, and (b) 35,842 lbs. milk, testing 4.1% fat? 

 (Use Table XI, Appendix.) 



