The methods pursued with regard to the elimination or retention of the grape stalks vary in different parts of the Continent.  The most careful vignerons remove the stalks in the case of the finest growths of Burgundy; but in the making of champagne, and also in the Rheingau, from which part come the famous Hock wines, the stalks are allowed to remain.  In the Medoc districts, which produce the finest clarets, the stalks are likewise put into the fermentation vat; but this is considered to be a great mistake, since a long time elapses before the astringent taste of the wine subsides.  With the far-famed Red Hermitage wine of France, too, the stalks are permitted to pass into the vat, and in the case of sherry and port, as well, the stalks all take part in the fermentation, though it is believed that better results would be obtained by their removal.  But in all these old wine-producing countries of Europe the same customs have been followed from time immemorial, and they are not likely to be altered at present.

THE MAKING OF THE WINE—­THE MUST ITSELF.

The must—­that is, the juice expressed from the grape, but in which (juice) fermentation has not yet taken place—­is a fluid of very complex composition.  It is made up of a variety of ingredients, with which it is necessary to become familiar in order to follow, during the process of fermentation, its change into wine.  We find, therefore, that a large part of the must consists of water; this serves to dissolve the other constituents, and to dilute them to the required extent.  For instance, the sugar in the must needs to be considerably diluted for the purposes of fermentation.  In too concentrated a form it actually prevents it, as we see when fruits are preserved in syrup.

Next to water, sugar is the material which exists in the largest proportions in the must; it is, however, that peculiar kind of sugar termed “glucose,” which may be described as uncrystallisable sugar, and as consisting of half grape sugar and half fruit sugar.  It possesses the property of being able to ferment, which cane or crystallisable sugar cannot do, unless, indeed, it first be changed into glucose.  Now, it is a curious fact that although cane sugar can be transformed into glucose, yet the latter form of sugar has never, so far, been changed into cane or crystallisable sugar.  As Mr. J.A.  Despeissis points out, the invention of a process that would achieve this would be worth more than all the mines of New South Wales put together.

In the process of fermentation the glucose is broken up into a number of substances, which differ entirely from it; and as these different bodies are very important they deserve much attention.  Under the influence of fermentation glucose undergoes a great change, of which the principal products are alcohol and carbonic acid gas.  The alcohol is, of course, the one predominant feature in wine; and according to the amount of alcohol which wine contains, so it varies in strength.