MILK-PLANT OPERATION. 



45 



water and using the specific gravities of milk and cream of various 

 percentages as given in United States Department of Agriculture 

 JBulletin No. 98, the following table has been worked out as to the 

 weights per gallon, at a temperature of 68° F. 



Table 15.- 



-Weight per gallon and specific gravity of milk and cream having various 

 fat contents. 



Commodity. 



Fat 

 con- 

 tent. 



Specific 

 gravity. 



Weight 



per 

 gallon. 



Commodity. 



Fat 

 con- 

 tent. 



Specific 

 gravity. 



Weight 



per 

 gallon. 



AVater 



Ptr 

 cent. 



1.000 

 1.037 

 1.034 

 1.0.33 

 1.032 

 1.031 

 1.030 

 1.025 

 1.018 

 1.015 



Pounds. 

 8. 32162 

 8.6295 

 8.6045 

 8.5962 

 8. 5879 

 8. .5796 

 8. .5713 

 8. .5297 

 8. 4714 

 8.4464 



Cream. 



Per 

 cent. 



20 



22 



25 



28 



30 



32 



35 



38 



40 



1.013 

 1.011 

 1.008 

 1.006 

 1.004 

 1.002 

 .999 

 .997 

 .995 



Pounds. 

 8. 429S 



Skim milk. . . 



0.025 



3 



3.5 



4 



5 



6 

 10 

 15 

 18 



do.. 



8. 4132 



Milk 



do 



8.3882 



Do.. 



do. . 



8 3715 



Do 



do 



8. 3519 



Do. 



do.. . 



8 3383 



Do 



do 



8.3133 



Mixed milk and cream . . . 



do 



8.2967 



Do 



do 



8.2800 



Cream 











Weights are given at 68° F. because that is the temperature used 

 in determining the specific gravities, being equivalent to 20° C, 

 the temperature generally used for such work. There w^ould be a 

 slio;ht difference for milk at 50° to 60° F., the temperature at w^hich 

 milk is usually received at the plant. 



The determinations above w^ere made on standardized milk and 

 cream, that is, mixtures of skim milk and cream of various per- 

 centages of butterfat. Figures for normal milk containing from 3 

 to 6 per cent butterfat would vary slightly from those given. For 

 all practical purposes the weight of whole milk may be figured at 

 8.6 pounds a gallon. 



