54 A Handbook for Dairymen 



cent of the total solids and not less than seven and 

 eight tenths (7.8) per cent of milk fat. 



" Sweetened condensed skimmed milk, sweetened 

 evaporated skimmed milk, sweetened concentrated 

 skimmed milk is the product resulting from the 

 evaporation of a considerable portion of the water 

 from skimmed milk to which sugar (sucrose) has 

 been added. It contains, all tolerances being allowed 

 for, not less than twenty-eight (28) per cent of 

 milk solids. 



"Unsweetened condensed skimmed milk, evapo- 

 rated skimmed mUk, concentrated skimmed milk, is 

 the product resulting from the evaporation of a con- 

 siderable portion of the water from skimmed milk, 

 and contains, all tolerances being allowed for, not 

 less than twenty (20) per cent of milk solids." 



Continuous Evaporators. 



Continuous evaporators evaporate the water from 

 the milk by heating the milk at atmospheric pressure. 

 No vacuum is used. With one type of machine the 

 milk is pre-heated and then delivered inside a hollow 

 copper drum. In this drum is a revolving dasher 

 with blades, similar to an ice-cream freezer. Out- 

 side the drum is an insulated jacket. Into the small 

 space between the drum and jacket live steam is ad- 

 mitted with 40 to 60 pounds' pressure. This heats 

 the milk and evaporates the water. Scrapers remove 

 the milk from the jacket and so keep it from burning. 

 Any desired concentration may be secured. After 

 being condensed the milk must be cooled. There is 

 a continuous flow of milk into the machine and of 

 condensed milk away from the machine. 



Another type of condensing evaporator is some- 

 what similar, except that air is blown through the 



