FREEZING THE MIX 155 



Effect of the Sugar Content on the Freezing Point. 1 - 



" Sugar goes into true solution and has a low molecular 

 weight as compared to egg or gelatine. It lowers the 

 freezing point very materially, and uniformly, in pro- 

 portion to its presence. Similarly the milk sugar, a nor- 

 mal milk constituent, being in true solution, causes milk 

 to freeze at a lower temperature than does pure water. 

 Ice cream sweetened to average taste contains approxi- 

 mately 14 per cent added sugar, and has a freezing point 

 of about 28^ F. When ice cream has frozen to the proper 

 consistency for removing from the freezer to the packers, 

 its temperature is about 28 to 27 F. The following 

 table, prepared from the data obtained at this station, 

 using a Beckmann's freezing-point thermometer graduated 

 in T ^Q of a degree, may be of interest as showing the 

 freezing points of different sugar solutions. 



Swell. The volume of ice cream obtained in excess of 

 the amount of total mix put into the freezer constitutes 

 the " swell " or overrun. This increase in volume is due 

 almost wholly to the incorporation of air into the product 

 and, therefore, can scarcely be called an overrun. Noth- 

 ing of a tangible character is added during the freezing 

 process. 



The /more viscous the cream is, the greater the swell 

 that may be secured, because the viscous cream is able 

 to retain the air that is beaten into it. 



The amount of swell is influenced by the rate of freezing. 

 1 Vermont Bui. No. 155. 



