EVAPORATED M1iLK—STRIKING 121 
should be sensitive and its scale should be subdivided into tenth 
degrees. The hatch should be “struck” at a uniform tempera- 
ture, savy 120 degrees F., so as to avoid misleading readings of 
the hydrometer. A difference of a few tenths degrees Beaumé 
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. 1f 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 
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. The hydrometer jar containing the sample 
of evaporated milk is set into the pail of hot water of the desired 
temperature, the hydrometer is inserted in the jar and the read- 
ing is taken. 
While the Beaumé 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 temperature and read the 
Beaumé 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 den- 
sitv shows a certain Beaumé 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,” 
control of the temperature of the sample taken. 
practically solves the 
The same formula, however, cannot be used under all con- 
ditions. No rule-of-thumb method of determining the density 
can therefore be established. Aside from the degree of conden- 
sation, the specific gravity ot the milk varies with locality, season 
of year, quality of milk, etc. This means that what is the proper 
Beaumé 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 
