Evaporated Milk — Striking 107 



the curd. This minimizes the danger of the formation of too 

 hard a curd in subsequent sterilization. It also lends the body 

 of the milk the appearance of greater consistency, gives it a 

 more viscous character and assists in the prevention of sub- 

 sequent fat separation. The superheating of evaporated milk is 

 not essential for the production oi quality and marketable prop- 

 erties, but it is looked upon by many manufacturers as a safe- 

 guard against such defects as curdiness and fat separation. It 

 is not improbable that its advantages are much overestimated, 

 and in most factories the superheating process is entirely omitted. 



The condensing of milk for the purpose of manufacturing 

 evaporated milk may be done also in the absence of the vacuum 

 pan, by the use of the "Continuous Concentrator," the construc- 

 tion and operation of which are described on pages 133 to 141. 



STRIKING 



The striking, or sampling and testing for density, of evapor- 

 ated milk, is more easily accomplished than that of the sweetened 

 condensed milk. When this product has nearly reached the 

 proper density, it is not viscous and syrupy, containing no cane 

 sugar. It resembles in consistency rich milk or thin cream and 

 has a specific gravity of LO.? to 1.075 at 15.5 degrees C. or 60 

 degrees F. 



Samples are drawn from the vacuum pan as described under 

 sweetened condensed milk and the density can be readily deter- 

 mined by means of a hydrometer. Beaume hydrometers, register- 

 ing from 5 to 15 degrees B., are generally used. As it is im- 

 portant that the deterrninations be accurate, the hydrometer 

 should be sensitive and its scale should be subdivided into tenth 

 degrees. The batch should be "struck" at a uniform temper- 

 ature, say 120 degrees F., so as to avoid misleading readings of 

 the hydrometer. A difference of a few tenths degrees Beaume 

 affects the behavior of the evaporated milk in the sterilizer very 

 appreciably. If the density is too great the product may badly 

 curdle during sterilization. If the density is too low the evapor- 

 ated milk may be below the legal standard. It is advisable for 

 the operator to use a pail of water of the proper temperature, 

 when he strikes the batch, so that he can adjust the temperature 

 of the milk in the hydrometer jar readily and quickly, and need 



