320 Milk and Its Products 



Milk that is abnormal in its properties when drawn, 

 badly contaminated milk, and milk that has not been 

 properly and promptly cooled on the farm cannot be 

 safely used in the condensery. Such milk either does 

 not withstand the trials of the process, or it succumbs 

 to the many and unfavorable conditions to which it is 

 subjected on its long journey from the factory to the 

 pantry of the consumer. Its original defects magnify 

 with age and follow it to its destination, resulting 

 usually in heavy loss to the manufacturer. 



Milk powders. Several processes for completely 

 removing the water from milk 'have been invented and 

 are in more or less successful operation. The resulting 

 product is in the form of a creamy white powder which 

 upon agitation readily unites with water, thus restoring 

 the milk. Skimmed milk thus treated is much used for 

 the manufacture of custards and other bakers' products ; 

 but the powder from whole milk soon becomes rancid 

 and is very little used. 



Dried casein, paper sizing. The casein of milk 

 in a dry form is useful in certain manufacturing 

 processes, and has been found to be particularly val- 

 uable for the preparation of sizing for paper, the 

 preparation of paint and various other uses. The 

 manufacture of dry casein for this purpose has 

 come to be an important means of utilizing 

 skimmed milk in many creameries, and its prepara- 

 tion is comparatively simple. The skimmed milk is 

 collected in a vat and the curd precipitated with a 

 mineral acid. A mixture of acetic and sulphuric 

 acids is commonly used, and from / to 1 per cent 



