Condensed Milk and Milk Powder 145 



heavy, thick and syrupy, and boils with much less violence. If, at 

 this stage of the process, excessive steam pressure is used in the 

 jacket and coils, the milk is superheated, often causing the precipi- 

 tation of "rice crystals." Again, where the finished condensed milk 

 is drawn from the pan very slowly, either owing to too small an 

 outlet in the bottom of the pan, or because the milk is forced to run 

 through a strainer attached to the outlet, or because the finished 

 condensed milk is retained in the pan as the result of an accident, 

 in all of these cases there is danger of superheating, and therefore, 

 of the production of these large crystals. .This danger is especially 

 great, where the valves of the steam pipes leading to the jacket and 

 coils are leaking, as is often the case. The avoidance of excessive 

 concentration and the removal of any conditions that tend to expose 

 the finished condensed milk to excessive heat will usually prevent 

 further trouble of this sort. 



Improper Cooling. — -The method used for cooling the sweet- 

 ened condensed milk after it leaves the vacuum pan is another 

 important factor determining the smoothness or grittiness of the 

 finished product. The chief principles involved here are the rapidity 

 and extent of cooling and the amount of agitation to which the 

 condensed milk is subjected. 



In order to fully appreciate the importance of strict attention 

 to' details in the cooling process of sweetened condensed milk, it 

 should be understood, that the formation of sugar crystals in con- 

 centrated solutions is enhanced by sudden chilling and by excessive 

 agitation of these solutions. The sudden and irregular chilling of 

 a part or all of the sweetened condensed milk in the cooling cans is 

 the result of the use of badly dented cans, poorly fitting paddles, a 

 warped condition of the pivots on which the cog wheels in the 

 bottom of the cooling vat revolve, too cold water, and the application 

 of too much cold water. 



The paddles must scrape all parts of the sides of the cans, from 

 top to 'bottom. This is possible only when the cans are intact and 

 their sides are smooth and free from indentations. The paddles 

 must be adjusted properly so that their edges fit snugly against the 

 sides of the cans, they must be firmly fastened to the cross bars and 

 forced against the sides of the cans by springs. In order that the 

 cans may run true they must properly fit into the rim of the cog 

 wheels in the bottom of the cooling vat and the pivots on which the 



