The mixing is usually effected in gigantic vats holding at times as many as 12,000 gallons each, and having fan-shaped appliances inside, which, on being worked by handles, ensure a complete amalgamation of the wine. This process of marrying wine on a gigantic scale is technically known as making the _cuvée_. Usually four-fifths of wine from black grapes are tempered by one-fifth of the juice of white ones. It is necessary that the first should comprise a more or less powerful dash of the finer growths both of the Mountain of Reims and of the River, while, as regards the latter, one or other of the delicate vintages of the Côte d’Avize is essential to the perfect _cuvée_. The aim is to combine and develop the special qualities of the respective crûs, body and vinosity being secured by the red vintages of Bouzy and Verzenay, softness and roundness by those of Ay and Dizy, and lightness, delicacy, and effervescence by the white growths of Avize and Cramant. The proportions are never absolute, but vary according to the manufacturer’s style of wine and the taste of the countries which form his principal markets. The wine at this period being imperfectly fermented and crude, the reader may imagine the delicacy and discrimination of palate requisite to judge of the flavour, finesse, and bouquet which the _cuvée_ is likely eventually to develop. These, however, are not the only matters to be considered. There is, above everything, the effervescence, which depends upon the quantity of carbonic acid gas the wine contains, and this, in turn, upon the amount of its natural saccharine. If the gas be present in excess, there will be a shattering of bottles and a flooding of cellars; and if there be a paucity the corks will refuse to pop, and the wine to sparkle aright in the glass. Therefore the amount of saccharine in the _cuvée_ has to be accurately ascertained by means of a glucometer; and if it fails to reach the required standard, the deficiency is made up by the addition of the purest sugar-candy. If, on the other hand, there be an excess of saccharine, the only thing to be done is to defer the final blending and bottling until the superfluous saccharine matter has been absorbed by fermentation in the cask. The _cuvée_ completed, the blended wine, now resembling in taste and colour an ordinary acrid white wine, and giving to the uninitiated palate no promise of the exquisite delicacy and aroma it is destined to develop, is drawn off again into casks for further treatment. This comprises fining with some gelatinous substance, and, as a precaution against ropiness and other maladies, liquid tannin is at the same time frequently added to supply the place of the natural tannin which has departed from the wine with its reddish hue at the epoch of its first fermentation.