EVAPORATED MILK—STERILIZING 145 
the cost of manufacture. Jt should, therefore, be made use of 
only in exceptional cases, when it is known that a certain batch 
of milk could not be put through the higher sterilizing tempera- 
tures without causing the product to become permanently curdy. 
Standardization of Properties that Influence Behavior of 
Evaporated Milk toward Heat of Sterilization.—In the foregoing 
discussion of the sterilizing process no mention was made of 
~ methods to standardize the behavior of evaporated milk toward 
the sterilizing heat. It was clearly pointed out that, in the 
absence of such methods, it 1s impossible to lay down any one 
formula for sterilization that would give uniformly satisfactory 
results under diverse conditions of the product to be sterilized. 
The chemical, physical and physiological properties of milk are 
ever changing, and even slight changes in these properties often 
cause wide variations in the amount of heat the product will 
stand in the sterilizer. This in turn necessitates constant changes 
and modifications of the process, if a marketable product is to 
be the result. Too much must be left to the judgment and 
power of observation of the processer and this situation ob- 
viously results in excessive numbers of defective batches and 
in costly losses and wastes. 
The standardization of evaporated milk for percentage of 
fat and solids alone materially assists in narrowing down the 
range of variations in the behavior of the milk in the sterilizer, 
but it fails to adequately control those properties which have 
the greatest influence on the sensitiveness of this product toward 
sterilizing heat. ‘This problem has confronted the manufacturer 
of evaporated milk from the very beginning of the industry. 
Much experimental work has been done in an effort toward its 
permanent solution, but the results have largely been of local 
and temporary success and usefulness only. 
Within recent years the Mojonnier Bros. Co. of Chicago 
have developed and have furnished the industry with a simple, 
practical and systematic method and suitable equipment, for 
controlling the properties of this complex product with such 
a degree of accuracy that the adoption of a standard sterilizing 
formula has become feasible and practicable. 
