[411] ] Loivre is about seven miles from Reims on the road to Laon.
[412] ] It is calculated that wine, the grape sugar in which yields ten per cent of alcohol, according to the average in Champagne, would, if bottled immediately after pressing, produce enough carbonic acid gas to develop a pressure of thirty-two atmospheres. But such a pressure is never developed, as the wine is not bottled directly it leaves the press; besides which no bottle could stand it. From four to six atmospheres insure a lively explosion and a brisk creamy foam. It is necessary, therefore, that fermentation should have been carried on till at least three-fourths of the sugar have been converted into alcohol and carbonic acid gas before the wine is drawn off for bottling, for even the very best bottles burst under a pressure of eight atmospheres.
A few words on the origin and development of the effervescent properties of Champagne will not be out of place here. These are due, as already explained, to the presence of a large quantity of carbonic acid gas, the evolution of which has been prevented by the bottling of the wine prior to the end of the alcoholic fermentation. The source of carbonic acid gas exists in all wines, and they may be all rendered sparkling by the same method of treatment. Still, no effervescent wine can compare with the finest growths of the Champagne, for these possess the especial property of retaining a large portion of their sugar during, and even after, fermentation; besides which, the soil imparts a native bouquet that no other wine can match.
Carbonic acid gas is one of the two products of the fermentation of grape sugar, the other being alcohol. In wine fermented in casks it rises to the surface, and escapes through the bunghole left open for the purpose. The case is different with wine fermenting in bottles tightly secured by corks. Part of the gas developed rises into the chamber or vacant space left in the bottle, where, mingling with the atmospheric air, it exercises a constantly increasing pressure on the surface of the wine. This pressure at length becomes so strong as to keep all the gas subsequently formed dissolved in the wine itself, which it saturates, as it were, and thereby converts into sparkling wine. Upon the bottle being opened, the gas accumulated in the chamber rushes into the air, producing a slight explosion, or pop, and freeing from pressure the gas which had remained dissolved in the wine, and which in turn escapes in the shape of numberless tiny bubbles, forming the foam so pleasing to the eye on rising to the surface.
Sometimes on opening a bottle of Champagne the pop is loud, but the effervescence feeble and transitory; and, on the other hand, there is merely a slight explosion, and yet the wine froths and sparkles vigorously and continuously. The two bottles may contain the same quantity of gas, but in the one there is more in the chamber and less dissolved in the wine, and hence the loud pop and slight sparkle; while in the other the pressure is low, and the explosion consequently slighter, but there is more gas in the wine itself, and the effervescence is proportionately greater and more lasting. In the former case the wine has received the addition of, or has contained from the outset, some matter calculated to diminish its power of dissolving carbonic acid gas, and is unsuitable for making good sparkling wine. The nature of the effervescence is one of the best tests of the quality of the wine. Gas naturally dissolved does not all escape at once on the removal of the pressure, but, on the contrary, about two-thirds of it are retained by the viscidity of the wine. The better and more natural the wine, the more intimately the carbonic acid gas remains dissolved in it, and the finer its bubbles.
The form of the glass out of which Champagne is drunk has an influence on its effervescence. The wine sparkles far better in a glass terminating in a point, like the old-fashioned flûte, or the modern goblet or patera, with a hollow stem, than in one with a rounded bottom. The reason is that any point formed around the liquid, as instanced in the pointed bottoms of these glasses, or in the liquid, as may be proved by putting the end of a pointed glass rod into the wine, favours the disengagement of the gas. Powder of any kind presents a number of tiny points, and hence the dropping of a little powdered sugar into Champagne excites effervescence. Porous bodies like bread-crumbs produce the same effect. Even dust has a similar action; and the wine will froth better in a badly-wiped glass than in one perfectly clean, though it would hardly do to put forward such an excuse as this for using dirty goblets.
The lively pop of the cork is less esteemed in England than in certain circles in France, where many hosts would be sadly disappointed if the wine they put before their guests did not go off with a loud bang, causing the ladies to scream and the gentlemen to laugh. A brisk foam, too, is absolutely necessary for the prestige of the wine, and ‘grand mousseux’ is a quality much sought after by the general public on the other side of the Channel. It is not rare to meet with wines of a high class in which the removal of the cork produces a loud explosion; but unfortunately the brisk report and sharp but transitory rush of foam are features easily imparted by artificial means. The ordinary white wines of Lorraine and other provinces receive a certain addition of spirit and liqueur, and are then artificially charged with carbonic acid gas obtained from carbonate of lime, chalk, and similar materials, after the fashion in which soda-water is made. These wines, sold as Champagne, eject their corks with a loud pop, but three-fourths of the carbonic acid gas escape at the same time, and the wine soon becomes flat and dead; whereas a naturally sparkling wine of good quality left open for three hours and then recorked will be found fresh and drinkable the next day.
Both the explosion and the subsequent effervescence are aided by a high temperature, which assists the development of the gas. Cold has the opposite effect, and iced wine neither pops nor sparkles. It, however, retains, if genuine, the whole of the carbonic acid gas held dissolved, which is not the case with the imitations spoken of.
Were it not that the question has been seriously started on more than one occasion, and only solved to the satisfaction of the questioner by a chemico-anatomical explanation, it would hardly be worth while touching upon the supposed hurtfulness of the carbonic acid gas contained in sparkling wines. The fact of accidents frequently occurring in breweries, distilleries, wine-presses, &c., from the accumulation of this gas, to breathe which for a few seconds is mortal, has led some people to wonder how Champagne, whilst containing so large a proportion of it, can be swallowed with impunity. The gas, however, which produces fatal results when inhaled into the lungs, by depriving the blood of the oxygen which it should find there, has in the stomach a beneficial effect, serving to promote digestion. In drinking Champagne it is conveyed direct to this latter region, so that no danger whatever exists, any more than in the mineral waters.—Mainly condensed from E. J. Mauméné’s Traité du Travail des Vins.
[413] ] For a long time the most erroneous ideas as to the cause of such breakage and the means of preventing it prevailed. Tasting, which was most relied on for ascertaining how far fermentation had gone, could not be depended upon with accuracy, though the rule of thumb laid down by some makers was that the time to bottle with the least risk of breakage was when the sweet taste had disappeared, and vinous flavour developed itself. The aerometers subsequently introduced failed to answer the purpose, because the saccharine matter was not the only thing capable of influencing them. The result usually was either the bottling of a must so full of effervescence as to break the bottles, or of wine already completely fermented and incapable of effervescing at all.