46 WINE AND THE ART OF WINE TASTING. 



EARTHY TASTE (Terroso, It.; Terreux, Gout de terroir, Gout de pierre a 

 fusil, Fr.). By the term earthy a single definite taste must not be under- 

 stood, but divers flavors which are all in general disgusting or bad. 



In tasting, these flavors are perceived by the posterior part of the 

 mouth, and may have their origin in the soil, in the use of inappropriate 

 fertilizers, in the plants supporting the vines, or in the weeds infesting 

 the vineyard, etc. 



" The earthy taste is a vague term," writes Ottavi, and with justice, 

 for it is a taste which is not always very definite, resembling sometimes 

 earth, manure, flint, slate, nuts, willow, grass, etc. It is well known 

 that Aristolochia, Mercurialis, etc., if allowed to groAv in the vineyard, 

 communicate their flavor to the grapes, and therefore to the wine. 

 Pliny was not mistaken when he wrote: "In general, the vine takes up 

 with an astonishing facility the flavors of neighboring plants. The 

 grapes grown in the marshy soils of Padua have a taste of willow." 



Generally the earthy taste is not found in high-class or fine wines. I 

 say generally, because there are exceptions; for example, Chablis has a 

 slight flavor of flint, and yet it is a wine of a certain renown. 



Richelieu, speaking to Louis XV of a certain wine of Graves, said: 

 "// sent la pierre a fusil comme une vieille carabine" 



The flinty taste, writes Petit Lafitte, has something vinous and ener- 

 getic, which exactly recalls the sensation experienced by the olfactory 

 organs when a flint recently struck by the steel is held under the nose.* 



The diminution of the glycerine was also pointed out by Pasteur, who, besides, stated 

 that the tartaric acid did not dimmish. 



As the researches of Fritz have shown, many microbes are able to cause fermentation 

 of the glycerine ; thus, under the action of the Bacillus butylicus it is transformed into 

 butylic alcohol and butyric acid. 



Recently, B. Hass experimented with a view of ascertaining whether the bitter taste 

 was due to citric ether, as Miiller and other French chemists had supposed, or to some 

 resinous substance produced by changes of the aldehyde in presence of ammoniacal 

 compositions having their origin in the albuminoid matters of the wine. 



By exhausting a -wine which was afflicted with the bitter disease, and which he had 

 previously rendered alkaline with ether, he obtained a resin slightly soluble in water, 

 very soluble in alcohol and in acetic ether, insoluble in carbon bi-sulphide, turning 

 brown in contact with the alcohols, becoming greenish with ferric chloride, and having 

 the extremely bitter taste of the diseased wine. 



Hass has found by his experiments that the best way of curing a wine afflicted with 

 this malady, is by the use 01 oxidizing agents. Oxigenated water in small quantities is 

 inefficacious ; in larger quantities it destroys the bitter taste, but produces another not 

 less disgusting. The best results have been obtained by aeration. 



The wine is fortified by the addition of alcohol till it contains 13 per cent by -volume, 

 if of feeble character and liable to acetify. A current of air is then passed through the 

 wine for two hours, and the bitterness disappears completely. 



Filtration through pomace or cellulose has an excellent effect, the bitter substance 

 seeming to be removed by physical attraction. 



This disease may be said to have several stages. At first the wine is still clear, but 

 less fragrant, duller in color, and with a slight bitter taste. Later it acquires an odor 

 sui generis; the bitter taste increases, becoming piquant on account of the small quan- 

 tity of carbonic acid produced by the secondary fermentation which takes place. Finally 

 it loses its natural color, becoming brownish, with a tendency to blue; there has then 

 taken place a serious change in one of the principal components of the wine the 

 extractive matter and the wine has become an undrmkable liquid. 



* According to Doussieux, the earthy taste is due probably to the solution and evapora- 

 tion of a part of the mineral and metallic substances which are found in the soil of certain 

 vineyards. 



Petit Lafitte seems inclined to attribute the flinty taste to iron and alumina. 



Ladrey, on the other hand, accounts for it by the presence of much silica in the soil, 

 and many analyses show silica not only in the leaves and seeds of the vine, but also in 

 the wine. 



Joulie states that the flinty taste is due to the fact that pyroniac silica contains a bitu- 

 minous substance of organic origin, the peculiar taste of which is communicated to the 

 wine. 



It should also be remembered that the experiments of Thenard prove that silicate of 

 lime is much more soluble in water than was formerly believed. 



