328 The Frtjit and Cider Institute. [sept., 



ing alcoholic fermentation. Thus, for instance, Foxwhelp 

 apples yield a cider which possesses a distinctive flavour, due 

 solely to the apple, yet if one may rely on the evidence of 

 experienced cider-makers, unnoticeable in the apple itself or in 

 the juice prior to fermentation. Flavour, in this sense, is pro- 

 bably the most important factor to be considered when estimat- 

 ing the value of a variety. The third factor above-mentioned, 

 the rate of fermentation, is of very considerable importance from 

 the practical point of view, and appears hitherto to have been 

 neglected. It determines the nature of the cider from the point 

 of view of sweetness or of dryness. It has been recognised for 

 a long time that some ciders naturally remain sweet almost 

 indefinitely, while others ferment to dryness in the course 

 of a few weeks unless prevented by artificial means, such as the 

 use of preservatives — a practice, generally speaking, not to be 

 encouraged — or by filtration. The cause of such variations has 

 been determined in the laboratory at the Institute. It does not 

 appear to be the case that one particular variety of apple will 

 invariably yield a juice which ferments either slowly or rapidly ; 

 but, at the same time, there seems to be some relation between 

 the rate of fermentation and the nature of the variety, since 

 certain kinds show a tendency, as a rule, either towards slow or 

 rapid fermentation. 



Other factors, however, in addition to that of variety, are 

 undoubtedly of influence in determining the rate of fermenta- 

 tion, and it is hoped that further experiments during the 

 coming season will reveal the effects of the soil, the season, 

 the degree of ripeness, and other agencies in this direction. It 

 has been commonly supposed that a comparatively large per- 

 centage of tannin is responsible for the slow fermentation in 

 many instances, but it has been found in these experiments 

 that the percentage of tannin bears no relation whatever to the 

 rate of fermentation. One of the great aims of the modern 

 cider-maker is to obtain control over the fermentation, so that 

 he may check it at any desired point. To this end the use of 

 the filter has been introduced, but although this causes a 

 cessation of fermentation for a time, yet in many cases the 

 interval is very short, and the fermentation is renewed as 

 actively as before. The reason for this rapid fermentation 



