150 Milk and Its Products 



wholesome product for this particular purpose. The 

 expense of producing milk of this particular grade 

 is necessarily great, as the labor involved is very 

 much more than that required to produce ordinary 

 market milk, and the continual oversight by trained 

 men unavoidably increases the cost of production very 

 materially. Certified milk differs from pasteurized or 

 sterilized milk in this important essential. The 

 former is kept as clean and as free from foreign 

 matter as possible, while the latter is treated usually 

 to some degree of heat, to kill and prevent the 

 growth of objectionable bacteria. Perhaps the most 

 ideal condition for the consumption of milk is secured 

 when the milk is drawn by the young directly from 

 the mammary glands of the mother. However, when 

 the dairyman attempts to serve his customers in the 

 great cities, hundreds of miles from the source of 

 production, with a like quality of milk, many difficul- 

 ties are encountered, some of which are discussed in 

 the following pages. It is the aim of the producer 

 of certified milk to approach as nearly as possible 

 the ideal condition above mentioned by excluding all 

 foreign matter and by keeping the milk at a low 

 temperature. 



"Certified milk has been kept for months in a per- 

 fectly sweet condition. It has been sent from the 

 interior of this continent to Europe, and returned with- 

 out any indication of souring. After such a journey 

 or length of time, it would not, however, be considered 

 as safe for food as the fresh product, even though it 

 had not soured to any perceptible degree. 



