108 Evaporated Milk — Striking 



not depend entirely on the temperature of the milk in the pan 

 which may change several degrees while he is engaged in the 

 operation of striking. 



While the Beaume hydrometers should be used at the tem- 

 perature for which they are graduated, which is 60 degrees F., 

 they answer all practical purposes at any other temperature : 

 at 120 degrees F. for instance. The chief essential is to take the 

 reading at some uniform and definite ternperature and read the 

 Beaume at that same temperature in the case of every batch. In 

 that way the results are comparable. The operator soon learns 

 that at a given temperature the evaporated milk of proper 

 density shows a certain Beaume reading. When the reading is 

 higher or lower, the milk has either been condensed too much or 

 not enough. The use of the automatic "striker" described under 

 "Striking Sweetened Condensed Milk," practically solves the 

 control of the temperature of the sample taken. 



The same formula, however, cannot be used under all condi- 

 tions. No rule-of-thumb method of determining the density can 

 therefore be established. Aside from the degree of condensation, 

 the specific gravity of the milk varies with locality, season of 

 year, quality of milk, etc. This means that what is the proper 

 Beaume reading in one locality, or at one season in the same 

 locality, may be entirely wrong in another locality or at other 

 seasons in the same locality. If uniformity in the density and 

 behavior of the batches of evaporated milk is to be secured 

 throughout the year, the operator must watch the behavior of 

 his milk from day to day and from season to season and he 

 must modify the Beaume reading in accordance with the changing 

 conditions. This is one of the all important stages of manufac- 

 ture, where relentless and careful study and watchfulness are 

 indispensable. 



In order to make absolutely sure that the density of the evap- 

 orated milk is right, it is advisable to get it just as near right 

 as possible in the pan and then draw the milk from the pan 

 into a standardizing vat, large enough to accomodate the 

 entire batch or several batches. The operator then tests the milk 

 again and this second estimation he can perform more carefully, 

 because he is then relieved of the responsibility of attending to the 



