STORAGE 193 
Temperatures of 60 degrees F. or above are too high for satis- 
factory storage for a prolonged pericd of time and the higher 
the temperature the greater the resulting defect. 
Temperatures below the freezing point of water are also 
undesirable. The evaporated milk freezes and while so doing it 
expands sufficiently to swell the cans. Although this swelling 
disappears when the contents of the cans dissolve again, yet 
the swelling action tends to weaken the cans and may give rise 
to subsequent leakers. Again, the melted evaporated milk 1s 
prone to be grainy as the result of freezing. This is due to the 
fact that when freezing, the watery pertion separates from the 
curd and the latter contracts. When the milk thaws up the curd 
remains contracted and fails to form a smooth emulsion with 
the remainder of the milk. 
The sweetened condensed milk does not freeze, because it 
contains so concentrated a sugar solution that its freezing point 
is usually far below the refrigerating temperature. If itis packed 
in solder-sealed cans there is usually no bad effect from cold 
storage. ITowever, when packed in cans sealed with the friction 
cap or the burr cap, difficulties may arise. ‘These seals are not 
air-tight. Excessively low storage temperatures cause the con- 
tents to shrink appreciably. Suetion is formed and air is drawn 
in through the seal. When these cans again warm up, the vis- 
cous milk in the cans seals the microscopic openings, the air and 
the liquid expand but the air finds no exit. This causes the cans 
to swell. While the quality of the milk in these cans is not 1m- 
paired in the least, the swelled cans suggest gaseous fermenta- 
tion, which means spoiled milk and which is invariably rejected 
on the market. 
The temperatures at which condensed milk can be stored 
with least objectionable results, range between 32 and 50 de- 
grees F. 
Advisability of Storing.—\ heavy stock of condensed milk 
is a severe drain on the working capital of the condensery, in- 
volving the cost of the fresh milk, cane sugar, tinplate, boxes, 
solder, labels, coal and labor. 
Unless the manufacturer has successfully overcome and 
mastered all of the principal condensed milk defects, and, unless 
his experience justifies him in believing that his goods will stand 
