SWEETENED CONDENSED MILK COOLING 103 



are now made of such size that the hydrometer can be operated 

 in them, rendering the use of a separate hydrometer cylinder 

 unnecessary. The latest invention for facilitating the sampling 

 and striking is the automatic milk striker designed by Mojonnier 

 Bros. Co., Chicago. This ingenious- contrivance consists of a 

 motor-driven piston pump. The suction tube carrying the piston 

 extends from the dome of the pan into the boiling milk. This 

 tube projects at its upper end through the wall of the dome and 

 overflows into a hydrometer cylinder. This cylinder carries at 

 its upper end a chamber permitting unhindered motion of the 

 hydrometer and the end of this chamber which faces the operator 

 is equipped with a sight glass and a light. In the cylinder 

 reposes a Beaume hydrometer. Whenever the operator desires 

 to know the density of the condensed milk in the pan, he starts 

 the motor. The pump immediately fills the cylinder and the 

 hydrometer shows the density or Beaume reading. 



Drawing off the Condensed Milk, As soon as the evapora- 

 tion is completed, the steam is shut off from the jacket and coils, 

 the water valve is closed, the vacuum pump stopped and the 

 vacuum broken by opening the "blow-down" valve. The man- 

 hole cover is then removed and the vacuum pump started again 

 in order to> remove the hot air over the milk. The milk is drawn 

 into 40-quart cans or into tanks or cooling vats. The condensed 

 milk should be drawn from the pan as rapidly as possible to 

 prevent its superheating while in the pan. In some factories a 

 wire mesh or cloth strainer is attached to the outlet of the pan, 

 so that the condensed milk is strained before it runs into the 

 cans This practice is unnecessary and objectionable, as it tends 

 to retard the removal of the milk from the pan. 



COOLING. 



The sweetened condensed milk, as it comes from- the vacuum 

 pan, has a temperature of about 115 F. to 130 F. If it were 

 allowed to cool naturally, or on its own accord, i. e., if no effort 

 were made to cool it promptly, it would superheat and this would 

 cause it to become thick and cheesy in a short time. It is, there- 

 fore, essential that it be cooled at once. Formerly this was done 

 by drawing the milk from the pan into 40 quart cans, setting 

 these filled cans in tanks with ice water and stirring the con- 

 densed milk with a stick, 



