CHEMISTRY. 181 



Champagne. 



If wine be bottled before the fermentation is com- 

 pleted, part of the sugar remains undecomposed, the 

 fermentation will go on slowly in the bottle, and, on 

 drawing the cork, the wine sparkles in the glass, as, 

 for example, in Champagne. 



In Champagne wines the red are generally inferior, 

 because the species of fermentation required to ex- 

 tract the colour, dissipates part of the flavour. 



White and Red Wines. 



When the must is separated from the husk of the 

 red grape before it is fermented, the wine has little or 

 no colour : such are white wines. 



If, on the contrary, the husks are allowed to re- 

 main in the must while the fermentation is going on, 

 the alcohol generated dissolves the colouring matter 

 of the husks, and the wine is coloured: such are 

 called red wines. 



Hence white wines are often prepared from red 

 grapes, the liquor being drawn off before it has 

 acquired the red colour ; for it is only the skin of the 

 grape that gives the colour. 



Pure wine is a compound of water, alcohol, acid, 

 colour, vegetable extract, and sugar. The gradual 

 conversion of the ingredient last mentioned, the chief 

 operation that goes on in bottled wines, is the cause 

 of the change that they undergo. Heats and the agi- 

 tation of a voyage accelerate the imperceptible fer- 

 mentation, and ripen wines more speedily. 



Diluted alcohol, when inclosed in a bladder, be- 

 comes greatly concentrated; the watery particles 

 escaping, and the spirit remaining almost pure. It 

 has been suggested to take advantage of this process, 

 by closing the mouths of bottles with bladder instead 

 of cork. 



