Composition of Milk and Its Products. 21 



of acidity is generally allowed to develop therein pre- 

 vious 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 ma- 

 jority 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 pre- 

 vents 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 man- 

 ufactured and consumed in America; salted butter made 

 in Europe also contains considerably less salt than Amer- 

 ican butter (see Appendix). Butter contains all the fat 

 of the cream but a small portion which goes into the 

 butter milk, and a small unavoidable mechanical loss in- 

 cident to the handling of the products. Butter should 

 contain at least 80 per ct. of fat, and ordinarily contains 

 about 83 per ct. ; besides this amount of fat, butter is gen- 

 erally composed of, water about 13 per ct., curd and 

 milk sugar 1 per ct., and salt 3 per ct. 



Butter milk is similar to skim milk in composition, but 

 varies much more than this product, according to the 

 acidity, temperature, and thickness of the cream, and 

 other churning factors. It contains about 9 per ct. of 

 solids, viz., milk sugar (and lactic acid) 4 per ct., casein 

 and albumen 4 per ct., fat .3 per ct., and ash .7 per ct. 



26. The quantities of butter and by-products obtained 

 in the manufacture of butter are as follows: 1000 Ibs. of 

 milk of average quality will give about 850 Ibs. of skim 

 milk and 145 Ibs. of cream (separator slime and mechan- 

 ical loss, 5 Ibs. ) ; this amount of cream will make about 

 42 Ibs. of butter and 100 Ibs. of butter milk (mechanical 

 loss, 3 Ibs.). 



