10 



BULLETIN 1123, U. S. DEPARTMENT OF AGRICITLTTTKE. 



are necessary, the square method ^ is used. The calculations for the 

 square method are as follows : 



33.0 



9.77 



29. 40 total number of parts. 

 557-^29.4=18.94. 



18.94X9.77=185 pounds of cream. 

 18.94X19.63=372 pounds of whole milk. 



The accuracy of the calculations can be ascertained by comparing 

 the sum of the figures in each column with the stipulated amounts 

 placed at the top of each column. 



When this has been done the ingredients are proportioned by 

 careful weighing. The mix is then ready to be pasteurized and 

 homogenized. 



ROUGH ESTIMATES FOR PROPORTIONING INGREDIENTS. 



Whenever a mix is made from an unlimited quantity of condensed 

 whole milk the amount of condensed milk required is determined by 

 first making a rough estimate. For instance, in example 5, it is not 

 known what part of the total amount of milk solids not fat of the mix 

 must come from the condensed milk, so that what is thought to be 

 about the right amount is tried. In this case the figure taken to 

 begin with was 220 pounds. This figure is taken because from expe- 

 rience it is known that about 50 per cent of the milk solids not fat in 

 the mix must come from the condensed milk. That quantity divided 

 by 22 (the per cent of milk solids not fat in the condensed milk) 

 shows that it will require about 220 pounds of the condensed milk. 

 This amount would add 22 pounds of fat and 48.4 pounds of milk 

 solids not fat to the milk. 



To tell whether or not this is right simply take the difference 

 between the total amount of ingredients already calculated (that is, 

 the pounds of sugar, gelatin, and condensed milk) and the total weight 

 of the mix, and subtract the difference between the fat used in the 

 condensed milk and the total amount required to find the amount of 

 milk serum. Then multiply this figure by 0.093 to get approximately 

 the amount of milk solids not fat that will come from the milk and 

 cream and the sum of the two will indicate whether the proportions 

 are correct, thus: 



990- (138.5 + 49.5 + 220) =582 pounds of milk and cream. 

 582- (99-22) =505 pounds of milk serum. 

 505 X 0.093 =47 pounds of milk solids not fat from serum. 

 47 + 48.4 =95.4 pounds of milk solids not fat in mix. 



8 See p. 6. 



