Condensed Milk and Milk Powder 147 



ture of this sediment also differs in ' different cases of 

 settled milk. It may be soft, and upon stirring may mix in and 

 dissolve readily, or it may be very dry and hard, in which case it 

 sticks to the bottom of the can with great tenacity, and can be 

 removed and mixed into the milk with difficulty only. Like gritty 

 milk, settled 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 set- 

 tled 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 form of crystals. The absence of crystals then, 

 means that condensed milk will not settle ; but experience has shown 

 that it is a practical impossibility to* manufacture sweetened con- 

 densed milk which contains no sugar crystals. 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 conducive of sandy or gritty milk, diminishes 

 the tendency of the formation of sugar sediment. The successful 

 and uniform production 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 thinner 

 the condensed milk, the greater the difference between the specific 

 gravity of the liquid portion and that of the sugar crystals; there- 

 fore, the more readily will the crystals sink to the bottom. The 

 viscosity of thin condensed milk, also, is less than that of thick milk, 

 offering less resistance to the force of gravity of the crystals. In 

 the manufacture of sweetened condensed milk that has the proper 

 density, about 2.5 to 2.8 parts of fresh milk are condensed into one 

 part of condensed milk. If 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. 



Effect of Eat Content on Sugar Sediment. — The per cent, of fat 

 in milk, also, influences the specific gravity of the condensed milk, 

 and therefore, has some effect on the settling of the sugar crystals, 



