310 MASSACHUSETTS AGRICULTURE. 



with the object in view, whether it be to obtain butter for 

 immediate use or for keeping. To avoid some of the results 

 which attend the working of fresh, sweet cream, the following 

 course is frequently pursued : — The cream is placed in suitable 

 vessels, and kept at a moderate temperature (54° to 5»° F.) 

 until it is rendered more compact, and at the same time acquires 

 a slight acid reaction, in consequence of which the milk-sugar 

 is effectually destroyed ; the watery liquid which settles under 

 the cream is carefully removed, and the cream churned at a 

 temperature of 54° F. All these, and also the succeeding 

 operations, tend simply to remove the fat globules as soon as 

 practicable from the remaining constituents of the milk — the 

 milk-sugar and casein in particular, and to accomplish this end 

 by means which do not decompose the fatty compounds. 



Now aside from the well-recognized beneficial influence of 

 good pasture and water, it is manifest that the fragrance and 

 sweetness of butter depend, to a large extent, if not entirely, 

 on an unimpaired neutral state of the various fatty compounds 

 of which the butter consists ; whatever induces changes in 

 these, is detrimental, and ought to be excluded. An unneces- 

 sary exposure to the air at a higher temperature than 58° to 60° 

 F., particularly as long as the casein and the sugar of milk are 

 not yet entirely removed, and the butter itself is still in a 

 spongy condition, reacts most seriously in that direction. As 

 soon as the churning has been finished, we endeavor to remove 

 the buttermilk and render the fresh butter compact and hard. 

 To accomplish this, salt is added, either in the form of a fine 

 granulated mass, or in a concentrated solution, — the amount 

 depending to some extent on the quantity of moisture in the 

 butter. The salt acts in various directions : it contracts the 

 butter, and thus causes a free discharge of the buttermilk ; it 

 dissolves the coagulated casein, and thereby aids to remove it ; 

 it fills the fat mass with a saturated saline solution, which ex- 

 cludes the air and serves as an antiseptic towards the small 

 quantity of casein, which a limited washing has left behind. 



Casein is what chemists call a nitrogenous compound; it 



is most remarkable on account of its disposition to break up 



into disagreeably smelling and tasting substances, and to impart 



its own instability to other more stable compounds; as, for 



nstance, butter. Pure butter is the most complicated natural 



