198 Condensed Milk and Milk Powder 



Frequency of Examination. — Every day one can of condensed 

 milk or other product, one, three, ten, thirty and sixty days old, re- 

 spectively, is opened and the contents are carefully examined for 

 thickness, smoothness, sugar sediment, curdiness, fat separation, 

 color, flavor, fermentation-changes, etc. 



Technique of Examination.— Since the temperature of the 

 product influences its apparent thickness, it is desirable to examine 

 the condensed milk at a uniform temperature, preferably 60 or 70 

 degrees F. This is best accomplished by the use of a water-tight 

 tray of galvanized iron or tin, about twelve inches long, nine inches 

 wide, and three and a half inches deep, with an overflow about two 

 and a half inches above the bottom. Every day, at a regular hour, 

 the samples of the ages above stated, are placed into this tray, con- 

 taining water at the desired temperature (60 to 70 degrees F.,), about 

 thirty minutes before the cans are opened. All cans should be 

 placed in the tray right-side up. 



Upon opening the cans, the coating on the lid shows the pres- 

 ence of sugar sediment and of lumps of curd in the case of sweet- 

 ened condensed milk, and a layer of thick and buttery cream in the 

 case of evaporated milk. A perfectly clear lid, without any coating, 

 indicates the freedom of the product from these defects. In the 

 case of fermented milk the ends of the cans are usually bulged. 

 Upon opening, a part of the contents is forced out. The thickness 

 is estimated by inserting a spatula, or spoon, or by pouring, and the 

 flavor and smoothness are determined by tasting. 



The observations should be carefully recorded in a book re- 

 served for this purpose, and any changes observed, as the milk ad- 

 vances in age, should be noted. 



Interpretation of Results. — Most of the physical and mechan- 

 ical defects appear in milk from one to ten days old. Defects re- 

 sulting from fermentation processes generally become noticeable 

 two to three weeks after manufacture. 



Fluctuations in the thickness, from batch to batch, indicate lack 

 of proper attaition on the part of the pan-man to the "striking" of 

 the batches. Sugar sediment shows the need of closer attention to 

 the solution of sucrose and the cooling of the condensed milk. 

 Lumps and buttons suggest the acceptance of a poor quality of 



