FACTORY SANITATION 53 



a jacketed tank, or cooling it by running it into a large tank equipped 

 with cold air blowers, etc. 



The latest improved method for refrigerating the milk consists 

 of the use of large, usually circular, glass enameled steel tanks. 

 These tanks are completely surrounded on their sides and bottom 

 by a cold water or brine jacket and are equipped with a milk dis- 

 tributing device that causes the inflowing milk to be sprayed by 

 gravity against the top of the sides of the tank and to percolate in 

 a thin layer down the sides. In this manner the cooling is in- 

 stantaneous, the entire sides of the tank being surrounded by the 

 cooling medium. It is aimed to cool the milk to about 40 to 45 

 degrees F. and to hold it at this temperature until ready for manu- 

 facture. 



These glass enameled tanks have many advantages ; they 

 minimize the initial cost of the necessary equipment, reducing the 

 number of costly vacuum pans, and f orewarmers, required ; they 

 cut down labor cost, because they reduce the equipment to fewer 

 pieces to operate and to clean ; they are of such construction that 

 they are easily and quickly cleaned and readily kept in proper 

 sanitary condition, the smooth and pore-free enamel yields more 

 readily to the brush than copper surfaces ; they avoid all possibility 

 of chemical action of the milk on metal and, therefore, are a 

 reliable safeguard against the development of metallic flavor in 

 the milk. 



The use of these large holding tanks also facilitates the stand- 

 ardization of the milk for fat and solids not fat. For detailed direc- 

 tions on standardizing see Chapter XXIX, page 253. 



