134 Condensed Milk and Milk Powder 



"i. Evaporated milk should be prepared by evaporating fresh, 

 pure whole milk of healthy cows, oibtained by complete milking and 

 excluding all milkings within fifteen days before calving and seven 

 days after calving, provided that at the end of this seven day period 

 the animals are in a perfectly normal condition. 



"2. It should contain such percentages of total solids and of 

 fat that the sum of the two shall be not less than 34.3 and the 

 percentage of fat shall be not less than 7.8 per cent. 



"3. It should contain no added butter or butter oil incor- 

 porated either with whole milk or skimmed milk or with the evap- 

 orated milk at any stage of manufacture." 



■This modified standard was an improvement over the' original 

 standard which it superseded. However, the requirements of solids 

 were still too high. 



Difficulties of Meeting These Standards for Evaporated Milk. 

 — While these standards can be complied with in some localities and 

 under certain favorable conditions, they are beyond the reach of 

 the manufacturer in other localities and under less favorable con- 

 ditions. The manufacturer is compelled, in order to produce a 

 marketable product, to use sufficiently high temperatures in the 

 sterilizer to render the milk absolutely sterile. This he must ac- 

 complish without causing the product to become curdy. 



The degree of concentration of the evaporated milk directly 

 controls its curdling properties. The higher the degree of concen- 

 tration, the greater is the danger of a curdy product. Unfortunately, 

 the agents which regulate the ease with which milk curdles, are not 

 under the control of the operator. They have to do with breed, 

 period of lactation, condition, care and feed of the cows, season 

 of year, climatic and weather conditions and the care and chemical, 

 physical and physiological properties of the milk on the farm. It 

 so happens that in localities, where dairying has not as yet reached 

 a high state of development, where cows are exposed to inclement 

 weather, or in the southern tier of the dairy belt, where the cows 

 suffer from the sweltering heat of the summer months and are 

 pestered with flies, and where the available water for cooling the 

 milk on the farm is not very cold, the milk is more prone to curdle, 

 than in highly developed dairy countries, or in localities of the cooler 

 regions of the dairy belt, etc. 



The properties of milk to curdle, whatever the agents causing 

 them may be, are intensified by the degree of concentration. It is, 



