94 Sweetened Condensed Mii,k — Cooling 



vention 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 over- 

 flows into a hydrometer cylinder. This cylinder carries at its 

 upper end a chamber permitting unhindered motion of the hydro- 

 meter 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. 

 <^he 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 

 m-il^, 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. 



This was a very crude method, it involved much hard work 



