MILK SUPPLY AND CREAMERY PRODUCTS 53 



while air is whipped into, the cream by the rapid motion 

 of the beater. A great variety of excellent freezers of 

 this kind for hand or for power are on the market 

 which answer the purpose for making ice cream at 

 home or at the ice cream parlor. 



Coarse-grained salt and crushed ice, mixed in the 

 proportion of 1 part salt to 4 parts of ice, are constantly 

 filled into the space surrounding the ice cream can, and 

 the brine produced by the melting of the mixture is 

 gradually drawn off from the tub. In a good freezer 

 the operation should not take over fifteen minutes. 

 \Mien the cream is frozen to a soft mush, stop the beater 

 and scrape down the hard particles which may have 

 accumulated on the sides of the can, add any ingredients 

 which may be better incorporated at this stage than 

 mixed into the original material, such as crushed fruit 

 or preserves, and finish the freezing without carrying 

 it too far. 



Remove the beater, stir the cream which should still 

 be soft enough to handle, and pack in ice with only a 

 little salt. Or the cream may be transferred from the 

 freezer can to the shipping can and packed in it. If 

 bricks are wanted the soft cream is packed in molds of 

 the desired shape and size and buried in the freezing 

 mixture to harden. 



In modem ice cream factories Brine Freezers are gen- 

 erally used. In a Refrigerator Plant intensely low tem- 

 peratures are produced by the vaporizing of compressed 

 ammonia or carbonic acid in an ice machine, and brine 

 circulating in iron pipes is cooled by such medium and 

 may, in turn, cool the air in the Cold Storage room, or 

 the cream in the freezer, or pure water in metal boxes 

 for the manufacture of Artificial Ice. 



