104 SWEETENED CONDENSED MILK COOUNG 



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

 and time, and the quality of the product was poor. It w r as soon 

 found that the imperfect hand stirring caused excessive sugar 

 crystallization, which made the milk sandy. The sudden chilling 

 and irregular stirring of a saturated sugar solution like sweet- 

 ened condensed milk are favorable to the formation of sugar 

 crystals. Where the stirring is imperfect and irregular, all the 

 milk is not kept in sufficient motion to insure uniform and gradual 

 coaling. The milk next to the side of the cans is chilled too 

 abruptly, favoring the formation of crystals. Vigorous stirring 

 in itself is conducive of sugar crystallization. 



Later the hand stirring was completely superseded by 

 mechanical stirring, paddles closely scraping the sides of the 

 cans being used. Instead of setting the paddles in motio^n, they 

 are stationary and the cans revolve. The principle is similar 

 to that of the vertical ice cream freezer. Heavy iron tanks, with 

 a capacity of twelve to forty-eight 40-quart cans, are used for 

 this purpose. The bottoms of these tanks are equipped with a 

 system of cog wheels, set in motion by means of a gear at one 

 end of the tank. The wheels have a diameter large enough to 

 carry one can each. The cans are set on these wheels, the paddles 

 are inserted and fastened to cross-bars and the power started. 

 The cans should be heavily constructed to stand rough usage, 

 without suffering indentations. Cans with irregular, depressed, 

 or bulged sides cause the paddles to do poor work. Such cans 

 should be slipped over a wooden horn, or other contrivance, and 

 the indentations hammered out with a mallet. The paddles are 

 held stationary by cross-bars and are forced against the periphery 

 of the cans by springs. Attention should also be paid to the 

 pivots on which the cog wheels rest. If they are warped, the 

 wheels do not run true, so- that it is not possible for the paddles 

 to scrape the sides of the cans properly. 



The sweetened condensed milk should be cooled gradually. 

 Sudden chilling should be avoided. This is best accomplished 

 by warming the water in the cooling tank to about 90 degrees F., 

 before the cans are set in. The cans are then allowed to revolve 

 for fifteen to twenty minutes before any cold water is turned 

 into the tank. After that, cold water is turned in slowly until 

 the temperature of the milk has fallen to about 70 degrees F. The 



