SWEETENED CoNpENSED MiiK DEFECTS 229 
can be removed and mixed into the milk with difficulty only. 
Like gritty milk, settied milk is a very common condensed milk 
defect. Though it does not render the product less wholesome, 
it is an undesirable characteristic. Such milk is usually rejected 
on the market and results in a partial loss to the manufacturer. 
Causes and Prevention.—It is obvious, for reasons above 
referred to, that the conditions leading up to the production of 
settled milk, are closely related to those that cause milk to 
become gritty. Condensed milk cannot drop its milk sugar, 
unless the latter is present in the lorm of crystals. The absence 
of crystals then, means that condensed milk will not settle but 
experience has shown that it 1s a practical impossibility to manu- 
facture sweetened condensed milk which contains no sugar crys- 
tals. Sugar crystals are always present in it, and the fact that 
the milk is not sandy or gritty. does not necessarily mean that 
it will not settle. Nevertheless, the removal of conditions con- 
ducive of sandy or gritty milk, diminishes the tendency of the 
formation of sugar sediment. ‘The successful and uniform pro- 
duction of condensed milk that does not settle, however, involves 
additional conditions that are not controlled by the factors 
causing gritty milk. 
Effect of Density on Sugar Sediment.—One of the chief of 
these conditions is the density of the condensed milk. The thin- 
ner the condensed milk, the greater the difference between the 
specific gravity of the liquid portion and that of the sugar crys- 
tals; therefore, the more readily will the crystals sink to the 
bottom. ‘The viscosity of thin condensed milk, also, is less than 
that of thick mik, offering less resistance to the force of gravity 
of the erystals. In the manufacture of sweetened condensed 
milk that has the proper density, about 2.5 parts of fresh 
milk are condensed into one part of condensed milk. Tf the 
evaporation is stopped sooner, so that the ratio is much less than 
2.5 to 1, the condensed milk is usually too thin to hold its sugar 
crystals in suspension unless its specific gravity and viscosity 
are increased by the addition of more sucrose. 
Effect of Fat Content on Sugar Sediment.——The per cent of 
fat in milk, also, influences the specific gravity of the condensec 
milk, and therefore, has some effect on the settling of the sugar 
