(12) DAIRY RULES (Continued) 



6. Rule for finding the percentage of acid by Mann's acid test. 

 Multiply the number of cc. of alkali solution used, by .009 and divide 



the product by the number of cc. of the sample tested, the quotient when 

 multiplied by 100 will give the percentage. 



7. Rule for finding the percentage of overrun in butter. 



Subtract from the butter made, the pounds of fat in the cream used. 

 Divide the result by the butterfat in the cream and multiply by 100. This 

 equals the percentage of actual overrun. 



If 450 pounds of butter is made from cream containing 395 pounds of 

 fat, the pounds of overrun is (450 — 400 = 50) . The percentage is [(50 •*■ 400) X 

 100 = ] 12.5 per cent. 



8. To find the correct specific gravity of a sample when the temperature 

 is other than 60° F. 



Add one-tenth of a per cent to the reading for each degree above 60°, 

 and subtract one-tenth for each degree below 60°. 



RULES FOR STANDARDIZATION. 



In many cases it is necessary to change the per cent fat in milk or cream 

 to some other known per cent fat. This is called standardizing. In 

 much standardization work it is necessary to find the relative amount 

 of two different milks or creams of different percentages of fat to make a 

 certain amount of standardized milk or cream of a known per cent of fat. 

 This is found by: 



9. Subtracting the difference between the fat desired in the standard- 

 ized milk, and the milk of the lower fat content; and by subtracting the 

 difference between the percentage of fat in the milk of the lower fat content 

 and the percentage of fat in the milk or cream of the higher fat content. 

 The first result when divided into the last will give the percentage of the 

 amount wanted which must be used of the milk or cream of the higher fat 

 content. This amount taken from the total amount wanted will give the 

 amount of the lower milk or cream to be used, as: 



100 pounds of 3.5 per cent milk is desired. It is to be made from milk 

 testing 3 per cent and milk testing 5 per cent. 



3.5-3 = .5; 5-3 = 2. .5-h2 = .25. 25 per cent, or 1/4 of the mixture, 

 must be of the 5 per cent milk and 75 per cent of it must be of the 3 per' cent 

 milk. 100 — 25 = 75 pounds of the 3 per cent milk to be used; 25 pounds of 

 the 5 per cent milk to be used. 



