184 Testing Milk and Its Products. 



the Association reported that "in the ninety-day Colum- 

 bian Dairy Test, 96.67 per cent, of the fat in the whole 

 milk was recovered in the butter. This butter on the 

 average contained 82.37 per cent, butter fat; in other 

 words, 117.3 pounds of butter were made from each 100 

 pounds of butter fat in the whole milk. 1 The exact con- 

 version factor would be 1.173. As this is an awkward 

 number to use, and as 1^ is so nearly the same ... it 

 has seemed best to recommend that the latter be used as 

 the conversion factor. 7 ' 



A resolution was adopted by this association recom- 

 mending that the approximate equivalent of butter be 

 computed by multiplying the amount of butter fat by 1. 



These figures are the result of more than ordinary care 

 in skimming, churning and testing, and probably repre- 

 sent the minimum losses of fat in the manufacturing pro- 

 cesses. The increase of churn over test represented by 

 one-sixth, or 16 per cent., may therefore be taken as a 

 maximum " overrun" under ordinary factory conditions. 

 Butter makers who report overruns of 16-20 per cent, do 

 not show their expertness in butter making by such high 

 figures, but their lack of accuracy in testing, or careless- 

 ness in working the butter; a large overrun may be ob- 

 tained both by reading the test too low, and by leaving 

 an excess of water in the butter, through insufficient 

 working or other causes. 



219. Butter yield from milk of different richness, a. Use 

 of butter chart. The approximate yield of butter from 

 milk of different richness is shown in table XI in the 



i When 82.37 Ibs. of butter fat will make 100 Ibs. of butter, how much 

 butter will 96.67 Ibs. of butter fat make ? 82.37 : 96.67 : : 100 : x, x=117.3. 



