THE DIFFICULTIES OF FERMENTATION, 67 



barrel. In its earlier stages, however, fermentation can scarcely be 

 too active if it is not too long continued ; and all that need be said 

 for the management here, is that everything should be done to cool 

 the temperature ; the windows of the Cider house should be thrown 

 open, wet cloths thrown over the barrels, and water sprinkled about 

 to cause evaporation. 



Dilatory Fermentation. — This is a much more frequent and 

 troublesome difficulty, when cold weather sets in suddenly, as it so 

 often does in late autumn ; though it is more often caused by juice 

 of an inferior quality. If, however, it is simply a matter of tem- 

 perature, and if the tight closing up of the cider house is not 

 sufficient, the introduction of one or two small stoves will be the 

 best remedy. The fermentation may also be aided by drawing two 

 or three gallons of juice from the cask, warming it up to 70° (not 

 higher), and returning it again to the cask, and stirring up the 

 contents freely. The French recommend this stirring up to be done 

 frequently, with a long rod of birch twigs, introduced through the 

 bung hole. There is a fancy sometimes followed of adding a little 

 old Cider or Perry to the cask, and some go so far as to add a little 

 ordinary yeast from malt liquor, but these proceedings are somewhat 

 doubtful and rarely required. 



Persistent Fermentation. — The first fermentation will some- 

 times continue to go on in a subdued form, after its active stage is 

 over. This is called "fretting fermentation." It is the great diffi- 

 culty to be encountered with juices of inferior quality ; whether this 

 may arise from bad varieties of Apples and Pears, imperfect man- 

 agement of the fruit, or from the indifferent nature of the soil on 

 which the trees have been grown. The French chemists have had 

 much experience in the endeavour to remedy this difficulty, and 

 have obtained an amount of success that demands special notice. 

 They have established the fact that juices of an inferior character 

 are deficient not only in Glucose, but also in Tannin, and Mucilage. 

 When the first fermentation is over, they rack into a cask filled with 

 Sulphuric Acid fumes ; they add half a pound of extract of Catechu 



