CREAM RIPENING. 73 



uninformed as yet. Undesirable fermentations are 

 supposed to be retarded in cream and a process 

 of purification established by the development of 

 pure lactic acid' fermentation in cream. 



94. Fundamental principles involved. Cream ripen- 

 ing is a process of handling cream by which lactic 

 acid fermentation is allowed to develop to a degree 

 suitable to the American standard for sour cream 

 butter. This fermentation may be the result of the 

 natural ripening of cream or it may be brought 

 about by the introduction of a pure lactic acid 

 culture. The process called natural ripening of 

 cream is gradually giving place to the artificial 

 ripening of cream by means of the addition of a 

 pure lactic ferment culture. The principles involved 

 in the ripening of cream are the same now as they 

 ever were. There is a difEerence in the methods used 

 which is the result of study of the science and art 

 of practical butter-making. 



95. The physical condition of cream is changed by 

 the process of ripening. Sweet cream is smooth, 

 thin, and of a velvety nature, unless very rich, while 

 soured or ripened cream of the same richness as 

 unripened cream, is much thicker and its flavor is 

 rather coarse. The casein in sweet cream cannot be 

 seen with the naked eye while in soured cream it is 

 coagulated into fine particles by the action of lactic 

 acid. During the souring process the color of the 

 cream changes from a more or less yellowish tint 

 to a whitish shade with a peculiar shiny or glossy 

 surface. 



