96 CLEARING OE 



But wine may, however, be rendered colourless by 

 saturating its free acids with a base. 



By overlooking this fact, namely, that the colouring 

 matter of wine is soluble in alcohol and water with 

 tartaric acid, many, and amongst them Batillac,* have 

 been led to entertain very erroneous views respecting 

 the nature of the actual colouring matter of wine, and 

 the theory of that discolouration of wine w r hich occurs 

 during clearing. 



Isinglass produces much greater discolouration in 

 wines which are poor in alcohol and tartaric acid, 

 than in others. Where, however, the object in view 

 in clarifying, is not so much the removal of tannic 

 acid and colouring matter, as the separation of such of 

 these particles as, being in a state of minute division, 

 do not readily sink, other means are resorted to. In 

 Spain, powdered marble is mixed with white wines, 

 and gypsum or sand is used in other countries. 

 In warm climates the use of albumen and isinglass is 

 generally avoided, inasmuch as a portion of these 

 substances might easily remain in the wine and 

 spoil it. Powdered gum arabic is then used as 

 a clarifier ; gum is imperfectly dissolved in weak 

 spirit, and such particles as still float in the wine are 

 precipitated with it. Of the means mentioned, only 

 albumen and isinglass act chemically upon the wdne, 

 the others are purely mechanical. A little dissolved 

 gum may easily remain in the wine, the viscidity of 



* Traite sur les Vins de la France, p. 34. 





