CHURNING. 169 



butter about the size of pin-heads, and the individual circumstances 

 which influence the firmness and percentage of water in the texture 

 of the raw butter, are theoretically little understood. Up till now, 

 on this account, the rules for churning have been exclusively drawn 

 from practical experience alone. 



Butter of the best quality, and possessing the best keeping 

 properties, contains, as experience has shown, not more than 15 per 

 cent of water. It is neither soft nor oily, nor on the other hand 

 hard or friable, but possesses an average degree of softness and a 

 characteristic texture of grain, by which its origin from countless 

 quantities of individual globules and small lumps of hard fat can be 

 easily recognized under the microscope. Butter of this uniform quality 

 can only be obtained when churning is carried on neither too long 

 nor too short a time, and neither too slowly nor too quickly. The 

 best results are obtained when churning lasts for from thirty to forty- 

 five minutes, a period which is only limited by the exact violence 

 of the movement and the exact temperature of the liquid which is 

 being churned. Within certain narrow limits the violence of the 

 motion is in inverse proportion to the height of the temperature, so 

 that with a more or less powerful movement the same effect can be 

 produced as can be effected by a corresponding increase or decrease 

 of temperature. The art of making good butter from good ripe 

 milk or good ripe cream consists solely, for the above reasons, in so 

 regulating the temperature of the liquid for each individual churn, 

 and for the churns of different kinds, that the production of the raw 

 butter is effected in the prescribed time. Butter receives its texture 

 and its consistence in the churn during churning, and defects 

 which are produced during churning can be by no means sub- 

 sequently removed. 



The obstacles which retard the union or the coalescence of the butter 

 globules to form the lumps of fat are decreased with an increase in 

 the temperature of the fluid; and the more violent the motion, even to 

 such a degree that heat is produced, the more easily are they overcome. 

 It may be pointed out that where churning takes place too quickly, either 

 through too high a temperature or too violent a movement of the fluid, 

 the little lumps of raw butter do not separate out easily, but include, 

 besides the solidified fat, fatty globules which are in the liquid condition. 

 The author is further of opinion that the little lumps of fat take 

 up more butter-milk, in the form of small microscopic drops, the more 

 quickly they are formed. If the little lumps of butter contain liquid fat 



