u6 DAIRYING 



71. Why has spoiled, pasteurized milk such an offensive 

 odor, and what effect has pasteurizing on dirty and on clean milk f 



72. Describe "home" pasteurization, giving temperatures. 



73. What has made the "held" method of pasteurization 

 unpopular, and how may this be overcome? 



74. At what temperature are lactic acid or milk-souring 

 bacteria destroyed, and why is a higher temperature needed in 

 pasteurizing ? 



75. How may milk be pasteurized and still retain a cream 

 line in bottled milk? 



76. What advantage is obtained by cooling after heating in 

 pasteurizing milk? 



77. How long a time must milk be heated to 158, to 148 and 

 to 140 degrees F. in order to have it pass as pasteurized? 



78. How many pounds of milk testing 3% fat must be 

 mixed with 250 Ibs. milk testing 5% fat to give a mixture testing 

 4% fat? 



79. How many pounds milk testing 3% fat must be added 

 to 175 Ibs. cream testing 30% fat to give a mixture testing 20% 

 fat? 



80. How many pounds cream testing 25% fat can be made 

 from 60 Ibs. butter containing 82% fat, using skim milk to mix 

 with the butter? 



81. What are the objections to bottling milk from each, 

 cow as soon as she is milked? 



82. What are the objections to rubber parts in any ap- 

 paratus used for handling milk? 



83. Describe some of the important points in a sterilizing 

 oven used by a milk dealer. 



84. Describe the treatment of milk bottles from the time 

 they are received empty until filled with milk and ready for de- 

 livery. 



