198 BUTTER-MAKING. 



and thus prevents the fat which is at the surface from coming 

 in direct contact with the flavoring substances formed at the 

 bottom. If the surface layer of fat and casein were exposed 

 to favorable conditions, the point might be made that the sur- 

 face exposure is more desirable than if the fat were in a state 

 of perfect emulsion with the rest of the constituents of cream. 

 But such is not the case. The layer of fat and curdled casein, 

 when allowed to form at the surface, is likely to be contami- 

 nated with putrefactive organisms. Especially is this so if 

 the cream is allowed to stand in such a condition very long 

 in a warm ill- ventilated room. If the constituents of cream 

 are kept well mixed by stirring, the lactic acid checks the 

 development of putrefactive germs, which may accumulate at 

 the surface; the cream is ripened more evenly, and the flavor- 

 ing substances have the best facilities of coming in contact 

 with and being absorbed by the fat. 



The authors have noticed that high-scoring contest butter 

 is usually made from cream which has been stirred judiciously 

 at intervals. The most notable prize winners have stayed up 

 with their cream all night, or part of the night, to watch the 

 ripening process, and to stir the cream occasionally. It would 

 not be practical to advise this method, but cream should re- 

 ceive a judicious amount of stirring at intervals during the day, 

 and if it is allowed to stand over night, it should be stirred 

 the last thing in the evening before retiring. 



NATURAL AND ARTIFICIAL RIPENING. 



Cream-ripening as a whole, as practiced to-day, may be 

 divided into two groups: viz., (1) Natural, and (2) Artificial. 



Natural. Natural cream-ripening consists in letting the 

 raw cream stand at a certain temperature until it is sour, then 

 cooling it to the churning temperature. This method used to 

 be practiced nearly altogether, but now experimental and 

 practical evidence prove that this is not the method by which 

 the best butter can be produced. Natural ripening may, or 



