124 Dairy Bacteriology. 



tares at room temperature showed evidence of growth in 

 thirty trials in an average of 26 hours; 29 heated cultures 

 at room temperature all developed in an average of 50 

 hours, while the heated cultures kept in refrigerator showed 

 no growth in 45 days with but four exceptions. 



After the milk is pasteurized, it must of necessity be 

 stored and handled in germ-free receptacles. All utensils, 

 such as cans, dippers, bottles, etc., must be thoroughly 

 sterilized. For this purpose a sterilizing oven should be 

 had which is fitted with steam. Material of this sort, after 

 being thoroughly cleansed, should be steamed for one-half 

 to three-quarters of an hour. Sterilized bottles should be 

 kept protected from dust until they are used. 



Bottling and handling: the product. In bottling the 

 product it is necessary to keep the milk protected from re- 

 infection. It may be bottled from a large can with a bottom 

 faucet, or, on a large scale, with commercial bottling ma- 

 chines that fill several bottles at once. If " viscogen " is 

 added to restore consistency of cream, it should be done 

 before bottling, but not before the cream is thoroughly 

 cooled. The best bottles for the purpose are those that 

 have a plain pulp cap. All metal fastenings or stoppers 

 are dirt-catchers and are likely to get out of order. It is 

 our practice to heat pulp caps in paraffin, thereby render- 

 ing them more pliable and at the same time sterilizing 

 them. Bottles sealed with hot caps in this way are tightly 

 closed. 



In delivering pasteurized products, it is always neces- 

 sary to use care in handling to prevent the cream and milk 

 from being warmed up, and thus inciting into activity the 

 latent spores. 



