— 
oh 
CoMPOSITION AND Propverrres oF Mink Powbrrs 3 
Bolting.—'The powdered milk resulting from the spray dry- 
ing process of desiccation requires no grinding. It is very floury 
in its physical make up, and after sifting it is ready to be packed. 
Packing of Milk Powder.—The dried milk is put on the 
market in packages of various types, such as fibre containers, tin 
cans and barrels. The sizes vary from 8 ounce packages to 200 
pound barrels. Of the small size packages the 10 pound can with 
friction top predominates. The barrels vary some in net weight 
with the process of manufacture used, the granular product of 
the dough-drying and film-drying processes being heavier than the 
flaky product of the spray-drying process. 
The bulk of milk powder reaches the market in barrels; these 
are paper lined, similar as sugar barrels. 
CHAPTER XXVIII. 
COMPOSITION AND PROPERTIES OF 
MILK POWDERS. 
Chemical Composition of Milk Powders.—The chemical 
composition of milk powders varies principally with the percent- 
age composition of the original milk from which the powder is 
made, and to some extent with the process of desiccating. 
The percentage composition of the fluid milk is controlled 
primarily by locality and season of year, as determined by breed, 
period of lactation and feed of the cows. For these reasons milk 
powders made by the same process, but in different localities and 
at different seasons of the year, often show very considerable 
variations in their percentage composition. 
_ Effect of Atmospheric Conditions.—The atmospheric con- 
dition, especially with reference to humidity of the air, has a 
further, frequently quite material effect on the chemical composi- 
tion of the powder from the standpoint of dryness or moisture 
content. Experience has amply demonstrated that when there is 
a high degree of humidity in the atmosphere, the resulting milk 
powder shows a higher per cent moisture than when made on a 
clear, dry day. 
