220 THE AMERICAN FARMER. 



the cream is allowed to sour before churning, and curdy or caseous matter becomes mixed 

 with the butter, which soon gives it a rancid taste. 



In sweet cream, the hydrate of casein is less readily formed than in sour cream, hence 

 sweet cream requires more churning than the sour. The practice of churning milk, instead 

 of letting it stand for the cream to rise, is followed in some countries. Although very good 

 butter may be made in this manner, it requires much more labor, and the method of first 

 raising the cream is much to be preferred. 



Churning. Butter is the fatty substance extracted from the milk, and churning is the 

 operation in the manufacture of butter by which these fatty particles are separated from the 

 other constituents. By the churning process, by which means the whole mass of cream or 

 milk is kept constantly agitated, the fat or butter globules are caused to unite in larger 

 particles, and finally to separate entirely from the watery liquid, called buttermilk. As to 

 what is actually taking place at the formation of the butter in the churn, chemists differ. It 

 was the old hypothesis, and that advanced by Romanet, that each globule of fat suspended 

 in the milk serum was enclosed in a very thin membrane, and that by the -agitation or 

 concussion produced in the churning process, these membranes burst, or were torn open, 

 causing the butter grains to adhere together until a final separation of the fat globules, and 

 the watery portion was accomplished. 



The action being nearly alike on all the globules, the membranes enclosing them 

 would all break throughout the whole mass about the same instant. It was also supposed by 

 some, that acid in the cream caused the membrane to be dissolved or weakened sooner, and 

 for this reason butter was produced from sour cream sooner than from sweet. The existence 

 of the membrane of casein, or some albuminous matter, has however never been proved, 

 and the theory is being abandoned by the best chemists of the present day in both Europe 

 and this country, the present supposition being that the butter globules are simply suspended 

 in the milk serum without any membraneous covering whatever. 



Prof. Freytag, of Germany, holds to the opinion that the butter globules, although not 

 surrounded by a solid membrane, are, however, enclosed in a thin sheet of matters formed by 

 the commingling and condensing of casein, albumen, and milk sugar. 



Dr. Soghlet, of Vienna, after many experiments, arrived at the conclusion that the fat 

 in the milk must exist in a liquid or melted state, since the globules would keep their regular 

 globular form, even when cooling the cream to the freezing point of water, and that by 

 shaking or the agitation of the churning process these butter globules are made to thicken. 



Dr. Storck, of Denmark, after considerable investigation, with various microscopic 

 examinations at different stages in the mechanical process of churning, has advanced the 

 theory that the formation of butter in the churn is commenced by the agglutination of the 

 minute fat globules contained in the milk, but is completed by conglutination of the fat 

 globules in this state by means of a peculiar substance known to chemists as hydrate ot 

 casein, produced by the churning process. Which of the many theories respecting churning 

 is the correct one, or whether some entirely new theory yet to be advanced will supersede 

 them all, remains to be determined; yet we believe the old one concerning a membraneous 

 covering should be entirely set aside. &quot;We shall not attempt to decide where so many 

 chemists disagree. Neither is it of so much importance that farmers and dairymen should 

 understand the scientific reasons for the phenomena accompanying the mechanical process of 

 churning, as it is to know the best methods of doing it, and of attaining the highest possible 

 results in the manufacture of the butter product. 



One of the most important implements in the manufacture of butter is the churn. In the 

 rectangular churn the butter globules are caused to unite by the concussion of the whole 

 mass of cream against the sides of the churn, and the globules against each other, as it 

 revolves, no dashes or paddles being used. These churns are well adapted for use in cream 

 eries and large or small dairies, being fitted with cranks at both ends, and so arranged that 

 a pulley can be attached for connecting with power, if desired. 



