Condensed Miek and Miek Powder 165 



Lumps in Plain Condensed Bulk Milk. — Lumps are prone to 

 appear in plain condensed bttlk milk, as this class of goods is usually 

 made from fresh milk that may be slightly sour, as is the case in 

 creameries and in milk plants where the surplus and the returned 

 milk is often manufactured into plain condensed hulk milk. This 

 defect can be avoided by neutralizing the milk before heating, with 

 an alkali (sodium bicarbonate or lime water), heating less intensely, 

 by not carrying the" condensing process quite so far, or by overcon- 

 densing before superheating and then diluting with distilled water to 

 the proper density, after superheating. If the plain condensed bulk 

 milk comes from the pan in lumpy condition, it can usually be re- 

 duced to a smooth body by passing it through an ice cream freezer at 

 ordinary temperatures. 



Lumps of Curd in Evaporated Milk. — The danger of lumpiness, 

 or curdiness in evaporated milk is greatly augmented by the fact 

 that, in addition to the causes named under plain condensed bulk 

 milk, the sterilizing process must be dealt with. The high sterilizing 

 temperature used, tends to precipitate the proteids of milk, and the 

 temperature cannot be reduced below certain limits without impair- 

 ing the keeping quality of the product. Most of the evaporated 

 milk, after sterilization, is subjected to the shaking process in which 

 the coagulum in the cans is reduced to a homogeneous creamy fluid, 

 provided that the curd is not too hard. A curd will form in the 

 sterilizer in the majority of cases. If it is soft enough, so that it 

 can be completely broken up, no harm is done. If it is so firm that 

 mechanical shaking fails to cause it to disappear, then the evaporated 

 milk will reach the market in lumpy condition and is difficult to sell. 



Effect of Quality of Fresh Milk. — 'The quality of fresh milk is 

 all important in preventing lumpy evaporated milk. The milk must 

 come from healthy cows in good, normal physical condition. It must 

 not contain colostrum milk nor be stripper milk and it must receive 

 the best of care on the farm and reach the factory perfectly sweet. 

 Milk that is not of high quality in every respect should not be re- 

 ceived at the factory. 1 



Effect of Concentration. — The more concentrated the evaporated 

 milk, the greater the danger of lumpiness. All the conditions caus- 

 ing lumpiness are intensified by the degree of concentration. The 

 manufacturer must, therefore, study the behavior of his product at 



1 For detailed discussion of relation of quality of fresh milk to curdine=s of eyaporated 

 milk see Chapter VIII on "Manufacture of Evaporated Milk," "Quality of Fresh Milk," 

 p. 81 



