CHAPTER 55 



Clean Milk Production 



By C. W. Larson 

 Professor of Dairy Husbandry, The Pennsylvania State College 



More than half of the milk produced in the United States is used for 

 direct consumption. Pure, clean milk is an excellent food and is cheap. 

 It contains all the essential elements for a complete and balanced ration 

 for man. On account of its being used by infants, children and invalids 

 who are least able to resist the effects of unclean food, and because milk is 

 so easily contaminated, it is essential that great care be taken in its pro- 

 duction and handling. 



CLASSES OF MILK 



Sanitary Milk is no definite class of milk. It is simply a term used to 

 designate good, clean milk produced with extra care. It - is usually sold at 

 a price somewhat above prevailing milk prices. 



Guaranteed Milk is milk that the producer guarantees to be produced 

 under certain conditions and usually with some standard of fat and bac- 

 terial content. 



Standardized Milk is milk which has been altered in its amount of 

 butter-fat by skimming or the adding of cream. 



Certified Milk is milk that has been produced under certain conditions 

 prescribed by a commission, usually consisting of a veterinarian, a physi- 

 cian, a chemist and a bacteriologist. The prescribed conditions include 

 scrupulously clean methods, healthy cows, healthy milkers and carefully 

 sterilized utensils. Such milk should not contain over 10,000 bacteria per 

 cubic centimeter. It is usually sold at a considerably higher price than 

 ordinary milk. 



Inspected Milk is produced from healthy cows that have been 

 inspected. The inspection involves an examination by a city or state 

 inspector of premises and methods. 



Pasteurized Milk is milk that has been heated to a sufficiently high 

 temperature to kill the harmful bacteria, or germs, and then immediately 

 cooled. The temperature to which it is heated varies with the length of 

 time it is held. For market milk, it is customary to heat to 140° to 145° F. 

 for twenty minutes. 



Modified Milk is high-class milk, such as certified or sanitary milk, 

 altered in composition to suit certain uses. Such milk is used for infants 

 and invalids. 



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