200 GRAPE CULTURE AND WINE-MAiaNG. 



and large parts of acids and salts being indicated by the taste, and 

 the mucilage weighing but little, the greater weight of the must 

 may be taken as a sure sign of the ^-reater quantity of sugar in 

 it ; consequently, of its greater value. To ascertain this correctly, 

 the must has only to be still sweety and ncft made cloudy by earthy, 

 yeasty, and thready parts, as these may hinder the proper sinking 

 of the instrument. The fluids we wish to weigh must also have 

 an equal degree of temperature, as heat expands bodies ; and a 

 like quantity consequently weighs less if warmer than a colder 

 one of the same contents. 



Mr. Berg says of the must of Wiirtemberg grapes that such as 

 weigh 1060 or less make a bad wine ; that of 1065 an inferior, but 

 drinkable ; and heavier, up to 1080, a better and better quality. 



If the specific gravity of the must amounts to 1060 or 1070, 

 the sugar gets, at the first proper fermentation, so dissolved that 

 the taste can hardly discern it. If the specific gravity rises to 

 1075, or still higher, the wine is only a little sweet ; if it rises 

 still more, to 1085 or 1090, a great quantity of sugar remains in 

 an undissolved state after the first fermentation, which is not 

 changed until later into alcohol by a continued still fermentation ; 

 the wine not only getting by it more durable, but also stronger, 

 provided it is kept in good casks. 



Besides the sugar, the other matters contained in the sweet 

 must, such as vegetable acids, mucilage, tannic acid, etc., seem 

 to add but little to its weight. As soon as the first turbulent 

 fermentation is passed, the specific gravity of the must sinks to 

 that of water, and grows lighter the more alcohol has been form- 

 ed. The weight of such alcoholic wines is usually only by 0.010 

 or 0.012 larger than that of water mixed in the like proportion 

 with alcohol. 



The Wine-Scale serves also to prove old wines under certain 

 precautions. Wines of equal color and the same vintage are 

 usually the richer in alcohol the lighter they are. Neckar wines, 

 for instance, of the vintage 1825, showed, after eight months, 



Specific gravity 993, alcoholic par.ts 11.2 per cent. 

 " " 994, " " 10.8 " " 



" " 997, " " 7.0 " " 



" 999, " " 6.4 " " 



Old wines have in proportion frequently a larger specific gravity 

 than newer ones, also dark colored ones more than light colored. 

 The alcohol is closely united to the other parts of the wine, and, 

 in order to obtain all of it out of a wine, usually more than two 

 thirds of the must has to be distilled over again. 



The Acid-Scale, 



This is constructed similar to the vinegar-scale. A narrow 

 tube, closed at its lower end, has near the bottom (which point is 

 marked by 0) division lines marked 1, 2, 3, etc. It is filled with 



