WINE AND THE ART OF WINE TASTING. 



45 



in old and decrepit wines. This second bitterness, due perhaps more to 

 chemical reactions than to the action of ferments, is only relatively an 

 ill, as the wine can be consumed before it reaches complete decrepitude. 



Tasteur holds that even this second bitterness, which Vergnette 

 Lamotte lays to the account of decrepitude, is caused by the same or- 

 ganism which determines the first kind. 



This organism may remain inert for a longer or shorter period, till in 

 the course of aging the wine presents the necessary favorable conditions 

 for its development. 



In conclusion, I will say that the bitter taste is a somewhat serious 

 defect; a defect which may be more or less marked, as it may be transi- 

 tory or permanent.* 



* The bitter taste in wine may be the consequence of imperfect maturity of the grapes, 

 owing either to an unpropitious season, or to the damage caused by insect or crypto- 

 gamic pests; or it may be the consequence of a secondary fermentation, caused by a 

 micro-organism, i. e., the "bitter ferment," which determines the formation of those 

 substances which impart this taste to the wine. In the latter case we have a true 

 disease. 



When the bitterness is due to the principles which have passed from the grapes and 

 stems into the wine, then with time and successive finings and rackings it will disappear. 

 This is explained by the supposition that the nitrogenous substances become impreg- 

 nated with the bitter principles, and thus, when the former are precipitated, they carry 

 along with them the latter, the wine in this way losing this defect. 



The bitter taste, if very pronounced, may not disappear after the first rackings, in which 

 case the wine should be fined with gelatine or white of egg. 



If the wine be weak, the coagulation of the albumen may be facilitated by the addi- 

 tion of alcohol. 



According to the quality of the wine, it may be given a light clarification with the 

 whites of three or four eggs per hectolitre, or a more energetic treatment with 25 grammes 

 of gelatine. 



Such a treatment not being found sufficient, recourse must be had to the use of olive 

 oil of good quality; of this the dose to be used is one half litre per hectolitre. The oil 

 is poured into the wine, the whole thoroughly stirred, and then allowed to rest; the oil 

 separates from the wine, and carries with it the substances which have caused the bit- 

 terness. 



Directly after racking a wine with access of air, it will sometimes become slightly 

 bitter; this seems to be caused by the action of the oxygen of the air upon substances 

 contained in the wine; later the bitterness disappears, owing very probably to the rapid 

 oxidation which causes these substances to precipitate. In this way M. Mona explains 

 how bitter wines in bottles can, with time, lose this defect. 



Formerly various opinions were held regarding this malady, because, in all probability, 

 people failed to distinguish between bitterness proper and the malady due to tartaric 

 fermentation, or "la pousse.'' 



Thus De Blassis attributed it to changes of the salts, especially of bi-tartrate of potash; 

 Machard to an invisible action of the fermentative principle, decomposing the last rem- 

 nants of sugar and salts in the wine; Leboeuf to an abnormal fermentation, which 

 produced, sometimes, citric ether, which has a bitter taste; Vergnette Lamotte to a 

 secondary fomentation, caused by a parasitic vegetation, which decomposed the wine in 

 consuming the coloring matter; Neubauer found that the quantity of tannin and of 

 coloring matter diminished with the progress of the malady. Finally Pasteur, after the 

 studv of many bitter wines, has demonstrated that this malady is caused by the action 



_( * * ii i j_ i _ j_i j j j *j : J.T . 



the Bordelais. He adds that this malady presents many diversities in its development, 

 according to the origin and the nature of the wine, but that all wines are subject to it. 



Ducleaux, in 1873, determined the volatile acids of bitter wines, the following being 

 the result of his analyses : 



The increase of total acidity in the sick wine being greater than could be accounted 

 for by the formation of acetic acid at the expense of the alcohol, it must be attributed 

 to the fermentation of the glycerine, which, in fact, had diminished. 



