CHAPTER VII 



MILK POWDER 



It is possible to reduce milk to a powder by the 

 elimination of the water and, at some later date, by 

 the addition of water again to turn the powder back 

 to milk. This powder is now commonly made in this 

 country after two different processes. One, the hot- 

 roll or film-drying process, and the other the spray 

 process. 



The hot-roll or film-drying processes in common 

 use are the Hatmaker and Ekenberg. Others are 

 Parsburg, Gathsmaun, Just and Buflovak. 



The spray processes are the Merrell-Soule and 

 Gray processes. Many of the processes and the 

 necessary apparatus are covered by patents, so that 

 manufacturers who use them are often obliged to 

 pay a royalty. 



Description of Standard Processes. 



The essential equipment required for the Hat- 

 maker process consists of two horizontal, hollow, 

 steam-heated, revolving metal cylinders. These 

 cylinders are installed sufficiently close to each other 

 so that all the milk comes in contact with the cylin- 

 ders. The surface of these cylinders is heated to 

 212° F. and below 270° F. The high temperature 

 reduces the solubility of the finished powder. The 

 patent claims that the treating of the milk with 

 calcium chloride or with the double salt of sodium 

 and calcium citrate, to reduce the acidity of the 

 milk, and with alkaline hypochlorite to preserve the 

 fatty acids in the finished product, causes the milk 



