Principles of Milk Preservation. 



105 



hours; 29 heated cultures at room temperature all de- 

 veloped in an average of 50 hours, while the heated 

 cultures kept in refrigerator showed no growth in 45 

 days with but four exceptions. 



105. Preparation of utensils. After the milk is 

 pasteurized, it must of necessity be stored and handled 



H.S. 



S.TP 



FIG. 20. Steam sterilizer for sterilizing utensils (cans, bottles, etc.). St. p., 

 steam pipe; St. p. v., vent for steam pipe; w. s., wire shelf; c, outlet cock for 

 condensed water. 



in germ free receptacles. All utensils such as cans, dip- 

 pers, bottles, etc., must be thoroughly sterilized. For 

 this purpose a sterilizing oven should be had which is 

 steam fitted, so that direct steam can be used. Material 

 of this sort after being thoroughly cleansed, should be 

 steamed for one-half to three-quarters of an hour. Ster- 

 ilized bottles should be kept protected from dust until 

 they are used. 



