400 Journal of Agriculture. [8 July, 1907., 



In addition to the variation in the chemical composition of the butter, 

 there are other factors which influence the overrun, and consequently the 

 amount of money available for distribution. It is not alone the amount 

 of butter that is made, but that for which payment is received that con- 

 trols the sum at the disposal of the Directors. Take a factory receiving 

 milk; — 10,000 lbs. milk testing 4 per cent., contains 400 lbs. fat. The 

 separator will take from that, say 1,000 lbs. of cream, or 10 per cent., 

 leaving 9,000 lbs. skim milk which contains, say .1 per cent, fat, equal 

 to 9 lbs. fat lost, leaving 391 lbs. fat in the cream, in which when churned 

 about 15 per cent, water, curd, etc., would be incorporated, making 

 450 lbs. butter, leaving 550 lbs. of buttermilk. This will contain, on an 

 average, .2 per cent, fat, or an additional loss of i.i lb. fat. 



Other unavoidable losses are due to milk being left in cans, etc., cream 

 and butter sticking about cans, churns, and other utensils. Experiments 

 have proved that losses from these sources amount to about 3 per cent, 

 of the total fat available, thus reducing the available fat by another 12 lbs. 

 that is: — 



Loss of fat in skim milk 



Loss of fat in buttermilk 



Loss of fat sticking to utensils. &c. 



This leaves 377.9 H^s. out of the original 400 lbs. of fat to make into 

 butter, which, with the addition of 20 per cent, overrun equals 377.9 x 

 1.20 = 453-48 lbs. commercial butter, instead of 400 x 1.20 = 480.0 

 lbs. commercial butter if no fat were lost. That is equal to a loss of 

 5.52 per cent, loss on the butter produced. 



If all the butter is packed in export boxes, 56^ to 56! lbs. are put 

 in each box and sold for 56 lbs., practically a loss of one per cent. 

 If a large amount is printed, which is the case in many factories, there is 

 generally a loss of 3 to 5 per cent, according to the method adopted. It 

 will average 3 per cent, although sometimes 56 lbs. can be got out of a 

 56I lb. box. If a factory prints 25 per cent, of its output, there is 3 

 per cent, loss on that which is equal to .75 per cent, on the whole out- 

 put, equal to 3. 40 11 lbs. and i per cent, on the remaining 75 per cent, or 

 .75 per cent, on the whole output equals 3.401 1 lbs. To state this clearly 

 we take 453.48 lbs. commercial butter: — 



Loss I to I lb. overweight per 56 lbs. box 



— 1 per cent, on f output ... ... 3.4011 lbs. 



Loss on i)rint butter, 3 per cent, on \ of 



output ... ... ... ... 3.401 1 



6.8022 lbs. 



This leaves 446.68 lbs. butter to receive payment for. or a loss of 1.58 

 per cent. That with the 5.52 per cent, lost above makes a total loss of 

 7.1 per cent., leaving an overrun of 12.9, practically 13 per cent, for dis- 

 tribution out of the original, or theoretical 20 per cent. 



The only difference between a factory receiving milk and one receiving 

 cream is that the former has a loss of 9 lbs. of fat in the skim milk which 

 would increase the overrun of the cream supply factory by i.i per cent. 



