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 
