Condensed Milk and Milk Powder 37 



PART II 



MANUFACTURE OF SWEETENED 

 CONDENSED MILK 



CHAPTER IV 



DEFINITION 



Sweetened condensed milk is cow's milk, condensed at the ratio 

 of 2V2 to 2% parts of fresh milk to 1 part condensed milk: It con- 

 tains considerable quantities of sucrose, usually about 40 per cent., 

 to preserve it. It is of semi-fluid consistency and reaches the mar- 

 ket in hermetically sealed tin cans, varying in size 1 from eight ounces 

 to one gallon, and in barrels similar to glucose barrels, holding from 

 three hundred to seven hundred pounds of condensed milk. When 

 made properly, sweetened condensed milk will keep for many 

 months, but is best when fresh. 



HEATING 



Purpose. — The first step in the process is to heat the milk to 

 near the boiling point. There are three chief reasons for which the 

 milk is heated, namely to destroy most of the bacteria, yeast, molds 

 and other organized and unorganized ferments, to facilitate the so- 

 lution of the sucrose, and to prevent the milk from burning on to 

 the heating surface in the vacuum pan. 



Destruction oe Ferments. — When the fresh milk arrives at 

 the factory it contains micro-organisms in varying numbers and of 

 different species. In some cases disease-producing bacteria may be 

 present, rendering the milk dangerous to the health and life of the 

 consumer, were it not heated to temperatures high enough to de- 

 stroy these germs. Again, milk may contain bacteria, yeast, molds 

 and enzymes that cause it to undergo undesirable fermentations 

 which, if allowed to pass into the condensed milk, may tend to 

 shorten the life and impair the wholesomeness and marketable prop- 

 erties of the latter. 



