20 Testing Milk and Its Products. 



casein and albumen, 4.3 per cent, milk sugar, and .5 per 

 cent. ash. 



The skim milk is made up of the milk serum (15) and 

 a small amount of fat, viz., toward .4 per cent, when 

 obtained by the gravity process, and less than .2 per 

 cent, in the case of separator skim milk. Milk set in 

 shallow pans in the air, or in deep cans in water above 

 60 F., will give skim milk containing one-half to over 

 one per cent, of fat. Skim milk is used as a food for 

 young farm animals or as human food, and in this 

 country only in exceptional cases, for the manufacture 

 of cheese. 



25. Cream is used for the manufacture of butter or 

 for direct consumption. In the former case a certain 

 amount of acidity is generally allowed to develop there- 

 in previous to the churning process. This secures a 

 more complete churning and produces peculiar flavors 

 in the butter, without which it would seem insipid to 

 the majority of people in this country. Nearly all 

 American butter is salted before being placed on the 

 market. Salt is a preservative and for a limited length 

 of time prevents butter from spoiling. Unsalted butter 

 made from sweet cream is a common food article in 

 Southern and Middle Europe, but only an insignificant 

 amount is manufactured and consumed in America; 

 salted butter made in Europe also contains considerably 

 less salt than American butter (see Appendix, Table I). 

 Butter contains all the fat of the cream except a small 

 portion which goes into the butter milk, and a small 

 unavci(l;il)l( k mechanical loss incident to the handling of 

 the products. Butter should contain at least 80 per 



