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ilizing ]\v heat, one can sow yeasts into the must as desired, and thus 

 bring- about a fermentation at will, but the cooked taste contributed 

 to the must by heating- is difficult if not impossible to overcome. 

 Heating or pasteurizing to check fermentation or insure keeping of 

 cider is also just as faulty, and is never necessary in a properly man- 

 aged cellar, unless one desires to preserve a partially fermented cider. 

 For this purpose pasteurization at 60 to 70^ C. is practicable with goods 

 which have sufficiently fermented in bottles to become sparkling. 



THE USE OF SPECIAL YEASTS. 



Having brought the fresh must into the casks or vats for fermenta- 

 tion, the modern cider maker has to consider not only the temperature 

 of the must and of the room and the various other conditions already 

 discussed, but also another question of very great importance: Shall 

 the fermentation be left to the organisms normally present on the 

 fruit and those which may at the time of grinding and pressing enter 

 the must from contact with the air, the machinery, and the vessels? 

 Every cider maker knows that under proper temperature conditions 

 fermentation will quickly ensue after the juice has been placed in a 

 receptacle. But the operator untrained in the scientific phases of this 

 subject may not know how readily numerous undesirable organisms 

 gain access to the fruit juice. These objectionable organisms are sure 

 to be present upon the fruit, and especiall}^ so if unclean and unsound 

 fruit is used. Or they may be present in parts of the machinery, 

 especially if any parts have been left vmcleaned after previous usage; 

 and, what is perhaps still more important, these organisms may be 

 present in great number in unclean barrels, casks, or other vessels. 



The numerous organisms (microscopic plants), both useful and harm- 

 ful, which grow readily in fruit must can not be discussed here. 

 Suffice it to sa}' that the quality of the resultant product de])ends ujpon 

 whether desirahle or undesirable or<jan!srn8 gain the mastery in the must 

 dwring in itial fermentation. 



In order to insure the ascendency of the true yeasts in the early 

 stages, and thus giye them the control of the entire process of fer- 

 mentation, there has recently been developed the practice of sowing 

 the must with pure cultures of yeasts. Very often now special races 

 of yeasts are used in order to secure certain desired qualities of 

 bouquet, etc., in the finished product. This practice is based upon the 

 same principles as those which induce the good housewife to employ 

 a proper yeast culture to make bread for the table. 



The discussion of this question in its various phases will not be 

 undertaken here, but it should ))e noted that the practice of using 

 pure and special cultures of yeast is becoming more and more common 

 in foreign countries. In Germany practically all the important fac- 

 tories visited employ these cultures, which are obtained in small flasks 



