40 CREAMERY BUTTER MAKIXG 



1 . Determine the percentage of fat in the sample under 

 consideration. 



2. Determine its specific gravit}'. 



3. From the fat and specific gravity calculate the solids 

 not fat and total solids. 



4. Compare the results obtained with the average 

 specific gravity, per cent of fat, solids not fat, and 

 total solids given for normal cows' milk, or compare 

 with the legal State Standard. 



5. In drawing conclusions remember that 



=- a. Fat is lighter than vv^ater. 



- b. Milk is heavier than water. 



c. Skimming increases the lactometer reading. 



- d. Skimming slightly increases solids not fat. 



- e. Skimming decreases fat and total solids. 



— f. Watering decreases fat, solids not fat, lac- 

 tometer reading, and total solids. 

 ^ g. Watering and skimming decrease fat (ma- 

 terially), solids not fat, and total solids. 

 h. The solids not fat are less variable than the 



fat. 

 i. Skimming and watering may give a normal 

 lactometer reading. 

 From i it is seen that a normal lactometer reading 

 is possible when milk is skimmed and watered in the right 

 proportions. A lactometer reading without a Babcock 

 test is therefore worthless. 



For herd milk a lactometer reading above 33.5 is posi- 

 tive evidence of skimming when accompanied with a low 

 percentage of fat. Herd milk showing a lactometer read- 

 ing below 28 is considered watered. 



Examples of milk adulteration in which onlv herd milk 

 is considered are given as follows : 



