398 THE OVERRUN 



Salt. The salt represents the next largest non-fatty con- 

 stituent of butter. The salt content of butter ranges from no 

 salt to about 4.5 per cent salt, averaging about 3 per cent. 



It is obvious that the more salt butter contains, other 

 factors being equal, the larger will be the overrun. Unsalted 

 butter, therefore, yields a much lower overrun than salted but- 

 ter, unless the legal moisture limit is exceeded or an abnormal 

 amount of curd is incorporated in the unsalted butter, both of 

 which practices are unlawful and would unfavorably affect the 

 keeping quality of the resulting butter. 



The difference in overrun between unsalted butter and 

 butter containing about 3 per cent salt is approximately 4.5 

 per cent. With the price of butter at 40 cents, the sale of un- 

 salted butter at the same price would cause the creamery to 

 sacrifice 1.8 cents on every pound of butter manufactured. In 

 other words, unsalted butter would have to be sold at a price 

 approximately 1.8 cents higher than salted butter in order to 

 secure the same returns for butterfat sold in the form of unsalted 

 butter as that sold in the form of salted butter. 



Curd. The curd content of butter is not generally consid- 

 ered a factor of consequence from the standpoint of overrun. 

 In properly made butter the curd content is small, averaging 

 about .7 of one per cent, and it is fairly constant. If butter were 

 not washed at all it would not exceed 1.5 per cent curd and 

 would average around 1 to 1.25 per cent. In properly washed 

 butter it is practically always below 1 per cent. In calculating 

 the overrun, the curd is usually figured to be 1 per cent, allow- 

 ing it to also represent the remaining traces of other non-fatty 

 constituents, the ash, milk sugar and acid. 



Efforts are made occasionally, however, to increase the over- 

 run by incorporating in butter, extraneous additional curd, in 

 the form of wet or dry casein, or skim milk powder. In such 

 cases the extraneous curd is added to the butter in the churn 

 with the salt and it is worked in during the regular process of 

 working. 



If the curd is so added, in form of starter, the increase of the 

 curd content in the butter is very slight and barely perceptible 

 by analysis, and there is no appreciable increase in the overrun. 



