SWEETENED CoNDENSED Mink DEFECTS 223. 
Sandy, Rough or Gritty Sweetened Condensed Milk. 
General Description.— This is condensed milk in which a por- 
tion of the milk sugar has been precipitated in the form cf large 
crystals, the size of the crystals depending on the conditions 
causing crystallization. First-class sweetened condensed milk 
is smooth and velvety. Such milk is not entirely free from sugar 
crystals, but they are so minute in size that they do not rob the 
condensed milk of its natural smoothness. In sandy or gritty 
condensed milk the eryvstals are very numerous and large enough 
to grind between the teeth, similar to salt crystals in gritty 
butter. The presence of these crystals is also noticeable to the 
naked eye; the milk looks candied. 
Causes and Prevention.—The sugar crystals which render 
the condensed milk rough and sandy consist largely of milk 
sugar. ‘The solubility of milk sugar is relatively low. Milk 
sugar requires about six times its weight of water at ordinary 
temperature for complete solution. Condensed milk contains 
from 12.5 to 15 per cent milk sugar and only about 26.5 per cent 
water. The ratio of milk sugar to water in sweetened con- 
densed milk, therefore, is 1:2, while for complete solution it 
should be 1:6. The milk sugar in this product is present in a 
supersaturated solution and any condition which favors sugar 
crystallization strongly tends to precipitate this milk sugar, 
because there is more of it present in the milk than the available 
water is capable of readily keeping in solution. The chief factor 
that prevents the milk sugar trom precipitating very badly is 
the great viscosity of the condensed milk. This is largely due 
to the caseous matter and the cane sugar. 
Cane Sugar Content.—It has been argued that the large 
amount of sucrose which sweetened condensed milk contains, 
is the principal cause of sandy milk and of sugar sediment in 
the bottom of the tin cans, and that a reduction in the amount 
of sucrose lessens the tendency of the sugar to crystallize and 
the milk to become sandy. This line of reasoning is erroneous. 
The presence, in water, of sucrose in solution does not materially 
lessen the power of the water to dissolve milk sugar, provided 
that the sucrose solution is not a saturated one. Sweetened 
condensed milk, contains about 35 to 45 per cent sucrose and 
