Xxil CONTENTS 



PAGES 



Butter from ice cream ...... 540 



Fat-content of different portions .... 541 



Shipping 541 



Modification table 542 



Testing ice cream for fat 543 



Ice cream score cards . . . . . . 543 



CHAPTER XV 



THE RELATION OF BACTERIA TO DAIRY PRODUCTS . . 547-573 



Relation of bacteria to milk 547 



Sources of bacterial contamination . . . 547 



Interior of udder 547 



Exterior of cow's body ..... 548 



The dairy utensils 549 



Development of bacteria in milk . . . 549 



Changes in milk due to bacteria .... 551 



Milk as a carrier of disease ..... 553 



Pasteurization of milk 555 



The quality of milk to be pasteurized . . 556 



Methods of pasteurization . . . . 556 



The "flash" process . . . . 557 



The "holder" process .... 557 



Temperatures and methods to be used . . 558 



Holding and delivery of pasteurized milk . 559 



Pasteurization of skim-milk and whey . . 560 



Delivery of hot skim-milk . . 562 



The whole milk must be sweet . . 562 



Feeding value of pasteurized skim-milk . 563 



Amount of water added to skim-milk by 



pasteurizing with steam . . . 563 



Pasteurizing buttermilk .... 564 



Tests for pasteurized milk .... 565 



Storch's test . . . . . 565 



Potassium iodide-starch test . . . 566 



Infectious mastitis . . . . . 567 



Relation of bacteria to butter 568 



Abnormal flavors . . . . . . 569 



Disease bacteria in butter * 569 



Relation of bacteria to cheese . >- . . . * 571 



Disease organisms in cheese .... 572 



