PREFACE. 



The manufacture of cider is an important adjunct to fruit growing 

 in the United States. A well-made cider is a beverage which is appre- 

 ciated by all and one which is within the reach of ever}- possessor of 

 an orchard. Cider is also a beverage which mav l)e manufactured 

 without the supervision of the excise officials. It is thus an industry 

 which can be widely extended and whose development will make the 

 growing of fruits more prohtable. 



It is evident that the principles which underlie the conduct of the 

 fermentation of apple juice in order to secure a product of a definite 

 chemical composition also apply to the juices of other fruits, such as 

 pears and peaches, and thus a Inilletin of this description affects, in 

 general, the fruit interests of the country wherever the juices of fruits 

 are employed for potable purposes. 



Up to the present time the manufacture of cider in the United States 

 has been conducted largely by empirical methods. Little has been done 

 toward the study of the chemical composition of the fruits, the fresh 

 juices, the fermenting musts, or the finished products. What is true 

 of wines is also true of ciders and other fermented fruit juices, viz, 

 that their excellence and healthful ness are dei)endent entirely upon 

 their chemical composition. The changes which take place in fruit 

 juices during fermentation are essentially chemical, and are produced 

 by ferments, which in these instances ma}" be regarded as chemical 

 reagents. 



In order that the manufacture of cider maj^ be conducted in a more 

 systematic and scientific manner in this country, it was deemed desir- 

 able to study the best processes employed in foreign countries, espe- 

 ciall}^ in England, France, and Germany, which are the principal cider- 

 producing countries of the world. To this end, Mr. William R. Ahvood 

 was employed by the Secretary of Agriculture as a special agent to 

 act under the direction of the Chief of the Bureau of Chemistry, and 

 was detailed to study the actual processes of manufacture in the coun- 

 tries named, as well as to conduct extensive experiments here. Mr. 

 Alwood, in addition to collecting valuable information of a practical 

 nature, has also ))rought together the scattered chemical data found 

 in difficultly accessible reports and papers, so as to make them available 



for use. 



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