126 



PURE FOOD IN THE HOME 



tect it by having the milk as free from germs as possible. 

 All milk contains some germs, even shortly after taken from 

 the cow, the most numerous being those which cause milk 

 to sour. To kill the harmful bacteria and not injure the 

 milk, a method known as pasteurization is used. This pro- 



A model kitchen. 



cess is named after the great French scientist, Louis 

 Pasteur, who did so much to apply his knowledge of harm- 

 ful germs to human betterment. By this method milk is 

 heated to a temperature of not over 150 degrees Fahrenheit 

 for a period of ten minutes to one half hour. The diagram 

 at the bottom of page 125 shows an excellent home pas- 

 teurization apparatus. In cities most milk delivered to 

 the home has been pasteurized, because the milk is some- 

 times forty-eight hours old before it is delivered to cus- 

 tomers. 



