Colouring. Wines are as commonly doctored in their colour as their flavour. A fawn-yellow and golden-sherry yellow are given by means of tincture or infusion of saffron, turmeric, or safflower, followed by a little spirit colouring, to prevent the colour being too lively. All shades of amber and fawn, to deep brown and brandy colour, are given by burnt sugar. Cochineal (either alone or with a little alum) gives a pink colour; beet-root and red sanders give a red colour; the extracts of rhatany and logwood, and the juice of elderberries, bilberries, &c., give a port-wine colour.
Crusting. To make port wine form a crust on the inside of the bottles, a spoonful of powdered catechu, or 1⁄2 a spoonful of finely powdered cream of tartar, is added to each bottle before corking it, after which the whole is well agitated. It is also a common practice to put the crust on the bottle before putting the wine into it, by employing a hot saturated solution of red tartar, thickened with gum and some powdered tartar.
Deacetification. This is effected by the
cautious addition of either salt of tartar or carbonate of soda. Wine so treated soon gets insipid by exposure and age; and, without care, the colour of red wines is thus frequently spoiled.
Deacidification. See Detartarization (below).
Decanting. This only refers to small quantities of wine, ready for consumption. In decanting wine, care must be taken not to shake or disturb the crust when moving it about or drawing the cork, particularly of port wine. Never decant wine without a wine-strainer, with some clean fine cambric in it, to prevent the crust and bits of cork going into the decanter. In decanting port wine, do not drain it too close; as there are generally two thirds of a wine-glassful of thick dregs in each bottle, which ought to be rejected. In white wine there is not much settling; but it should nevertheless be poured off very slowly, the bottle being raised gradually.
Decolouring. The colour of wine is precipitated by age and by exposure to the light. It is also artificially removed by the action of skimmed milk, lime water, milk of lime, and fresh burnt charcoal. Wine merchants avail themselves of this property for the purpose of whitening wines that have acquired a brown colour from the cask, or which are esteemed pale; and also for turning ‘pricked’ red or dark-coloured wines into white wines, in which a small degree of acidity is not so much perceived. In this way brown sherry is commonly converted into pale or gold-coloured sherry. For the latter purpose, 2 to 3 pints of skimmed milk are usually sufficient; but to decolour red wine 2 to 3 quarts or more will be required, according to the nature and intensity of the colour, or the shades of paleness desired. Charcoal is seldom used, as it removes the flavour as well as colour, but a little milk of lime may sometimes be advantageously substituted for milk, when the wine has much acidity, more particularly for red wines, which may even be rendered quite colourless by it.
Detartarization. Rhenish wines, even of the most propitious growths, and in the best condition, besides their tartar, contain a certain quantity of free tartaric acid, on the presence of which many of their leading properties depend. The excess of tartar is gradually deposited during the first years of the vatting, the sides of the vessels becoming more and more encrusted with it; but, owing to the continual addition of new wine and other causes, the liquid often gains such an excess of free tartaric acid as to acquire the faculty of redissolving the deposited tartar, which thus again disappears after a certain period. The taste and flavour of the wine are thus exalted, but the excess of acid makes the wine less agreeable in use, and probably less wholesome. Amateurs and manufacturers should therefore welcome a means of taking away the free
tartaric acid without altering, in any respect, the quality of the wine. This is pure neutral tartrate of potash. When this salt, in concentrated solution, is added to such a fluid as the above, the free acid combines with the neutral salt, and separates from the liquid under the form of the sparingly soluble bitartrate of potash. “If to 100 parts of a wine which contains one part of free tartaric acid we add 11⁄2 part of neutral tartrate of potash, there will separate on repose at 70° to 75° Fahr., 2 parts of crystallised tartar; and the wine will then contain only 1⁄2 part of tartar dissolved, in which there are only ·2 part of the original free acid; ·8 part of the original free acid having been withdrawn from the wine.” (Liebig’s ‘Annalen.’) This method is particularly applicable to recent must and to wines which do not contain much free acetic acid; but when this last is the case, so much acetate of potash is formed as occasionally to vitiate the taste of the liquor.
Fining. Wine is clarified in a similar manner to beer. White wines are usually fined by isinglass, in the proportion of about 11⁄2 oz. (dissolved in 11⁄2 pint of water, and thinned with some of the wine) to the hogshead. Red wines are generally fined with the whites of eggs, in the proportion of 15 to 20 to the pipe. Sometimes hartshorn shavings, or pale sweet glue, is substituted for isinglass.