436 AMERICAN GRAPE CULTURE. 



out going into detail, the rule may be briefly 

 stated thus : rich musts are benefited by, and 

 even require, a freer admission of air and a high- 

 er temperature than light and meager musts can 

 endure. Thorough fermentation is indispensa- 

 ble for making wholesome wine ; not necessa- 

 rily the conversion of all the sugar into alcohol, 

 but the conversion or deposition of all the yeast 

 or ferment with which the must is charged. 

 This is one of the prime conditions of that 

 " fineness" which is so essential for health as well 

 as enjoyment, that it may be said that no wine 

 can be good without it. 



The temperature under which fermentation 

 takes place actively, ranges from about sixty- 

 five to one hundred degrees, and the quantity 

 of sugar decomposed decreases as the tempera- 

 ture falls below seventy ; in other words, thor- 

 ough fermentation requires at least seventy 

 degrees of temperature. When it is much 

 above eighty, there is danger that fermentation 

 will go on too rapidly, even to the destruction 

 of the wine, if the must is not rich in sugar, 

 and also free from the destructive elements 

 that belong to unripeness in the fruit. 



Wine has heretofore been commonly treated 

 of as something without life, indeed, but unlike 



