396 THS OVERRUN 



the amount of fat that is required to make one pound of butter, 

 the more butter can be made from a given amount of fat, and 

 the larger, therefore, will be the overrun., Consequently, the 

 composition of the butter is the fundamental factor that con- 

 trols the overrun. Other factors which influence the overrun 

 are the accuracy of weights and tests of cream, butterfat 

 shortages of cream routes and cream stations, the number and 

 amount of mechanical losses of butterfat, such as loss of 

 fat in the skim milk, in the buttermilk and through factory leaks, 

 and accuracy of weights and tests of butter. 



Effect of Composition of Butter on Overrun. Of the non- 

 fatty constituents of butter, that control the overrun, the moist- 

 ure, salt and curd are the only ingredients that need be consid- 

 ered and the relative amount of which is large enough and is 

 sufficiently variable to materially affect the overrun. The other 

 non-fatty constituents, the ash, milk sugar and acid, all 

 together total less than .5 of one per cent, they are practically 

 constant and are not materially affected by the process of manu- 

 facture under all normal conditions. 



Moisture. The moisture exerts the greatest influence of 

 the non-fatty constituents, on the overrun. It is present in 

 larger amounts than all the other non-fatty constituents com- 

 bined and it is the most variable. Its maximum limit in the 

 United States is fixed by a ruling of the Internal Revenue De- 

 partment below 16 per cent. According to this ruling butter con- 

 taining 16 per cent moisture or over is no longer legal butter, 

 but is classed as adulterated butter. 



Under all reasonable conditions of manufacture and of 

 raw material, the moisture content of butter will not exceed 16 

 per cent. There are times and conditions, however, when but- 

 ter has an inherent tendency to naturally hold more moisture. 

 This is especially the case in early summer when the cows are 

 turned from dry feed to succulent pasture, and on account of 

 their ravenous appetite for green feed they consume a great 

 abundance of it. This causes the butterfat to have a low melt- 

 ing point and to be abnormally soft. In this soft condition it 

 mixes readily with water and has the power to retain relatively 

 large quantities of it. With intelligent control of the churn- 

 ing temperature and careful adjustment of the process of work- 



