[ 9 ] 



II. A Treatife on the Cultivation of th* Fine, and the Method 

 of making iV'uus. 



[Continued from Vol. IX. p. 342. J 



IIL General Precepts refpecling the Art of managing 

 Fermentation, 



VV HEN the grapes have acquired the proper degree of 

 maturity, if the atmofphere be not too cold, and if the vintage 

 be of the proper volume, fermentation has no need of aid or 

 attittance. But thefe conditions, without which it is impof- 

 lible to have a good refult, are not always united, and it be- 

 longs to art, in order to obtain a good fermentation, to com- 

 bine all thefe favourable circumltances^ and to remove every 

 thing prejudicial. 



The faults of fermentation arife naturally from the quality 

 of the grapes, which is the iubjeel of it; and from the tem- 

 perature of the air, which may be confidcred as a very pow- 

 erful auxiliary. 



Grapes may not contain a fufTiciency of fugar to produce a 

 fufficient formation of alcohol : and this vice may be owing 

 to the grapes not having attained to maturity, or to the fugar 

 being diluted in too considerable a quantity of water; or be- 

 caufe fugar, by the nature of the climate, cannot fuffi- 

 ciently develop itfelf. In all cafes there are two ways of 

 correcting the vice which exifts in the nature of the grapes; 

 the flrft confiiis in conveying into the muft that principle 

 which it wants : a proper addition of fugar prefents to fer- 

 mentation the materials necefiary for the formation of al- 

 cohol, and the deficiency of nature is fupplied by art. The 

 antients, it appears, were acquainted with this procefs, fince 

 they mixed honey with the muft which they caufed to fer- 

 ment. At prcfent, direct experiments have been made on 

 this fubject; but I mall confine myfelf to tranferibe here the 

 remits of thofe made by Macquer. 



" In the month of October 1776 I procured from a garden 

 at Paris a quantity of the white grapes called pincau and 

 metier fufficient to make from twenty-five to thirty quarts of 

 wine. They were wafte grapes, and taken, purpofely, in a 

 bad ftate of maturity, that there might be no hopes of 

 making potable wine from them : in nearly about a half of 

 them, fingle grapes and even whole clutters were fo green 

 that their acidity was infupportable. Without taking any 

 other precaution than to feparate what were putrid, I caufed 

 the reft to be bruifed with the iialks, and the juice to be 



exprefled 



