The Wine Press and the Cellar: A Manual for the Wine-Maker and the Cellar-Man

by Emmet H. Rixford

In Using the Substances, it is always best to experiment with a small quantity of wine, being careful to employ a dose proportioned to the extent of the degree of acidity. Thus, to a quart of wine add 15 or 20 grains of carbonate of magnesia (1 or 2 grammes per litre), little by little, shaking the bottle the while; again, but only when the wine is badly pricked, slack a suitable quantity of quicklime in water, and let it settle till the surface water becomes clear. Then add to the wine which has already received the carbonate of magnesia, 5 or 6 fluidrams of the lime water (2 centilitres), and shake the mixture; then pour in 2 or 3 fluidrams of alcohol (1 centilitre), and finally clarify it with albumen, using fresh milk in preference, from 1½ to 3 fluidrams to a quart (½ to 1 centilitre to a litre); cork the bottle, shake it well, and let it rest for three or four days, when by comparing the sample treated with the pricked wine, the effect will be seen.

This treatment varies according to the nature of the wine. If it is green and pricked, add 15 grains (1 gramme per litre) of tartrate of potassium to the magnesia; and if the wine has a dull color, after having added the milk, put in about 3 grains (22 centigrammes) of gelatine dissolved in about a fluidram (½ centilitre) of water; if the wine is turbid and hard to clarify, add a little more than a grain (8 centigrammes) of tannin in powder, before putting in the milk and gelatine.

Of course, the same proportion should be used in operating upon a larger quantity of wine.

If carbonate of magnesium, which is preferable to all others, cannot be obtained, the dose of lime water may be doubled, and in default of lime, powdered chalk, or marble and vine ash may be used, but with great prudence, and in smaller proportions, or solutions of the sub-carbonates of potash and soda. Great care should be exercised as to the quantity of the latter used, and they should not be employed in treating wine slightly attacked.

Mr. Boireau prefers the carbonate of magnesium to any other alkaline substance, because it affects the color less, and does not give bitterness to the pricked wines, nor render them unwholesome, as do the salts formed by alkalies with a potash, lime, or soda base. In medicine, carbonate of magnesium is used to correct sourness of the stomach (so also, we might add, is carbonate of sodium). For the same reason, decanted lime water is preferred to the sub-carbonate of lime, employed in the form of marble dust and powdered chalk; nevertheless, lime water in large doses makes a wine weak and bitter.

Brandy is added to these wines in order to replace the alcohol lost in the production of acetic acid. The preference given to milk for fining is founded upon the fact that it is alkaline, and therefore assists in removing the acid flavor of the wine while clarifying it. It is alkaline, however, only when it is fresh; skim-milk a day old is acid, and should not be used. Finally, the tartrate and carbonate of potassium employed to treat green and pricked wines, are used to neutralize the tartaric acid, and gelatine and tannin to facilitate the clarification and the precipitation of acid ferments.

Wines whose acid has been neutralized should be clarified, and then racked as soon as perfectly clear, according to the methods pointed out.

The acetic acid being formed at the expense of alcohol, the more acid the less alcohol, and hence the necessity of adding spirit, or, if the acidity is not too pronounced, of mixing with a full-bodied but ordinary wine; but those wines should not be kept, as they always retain acid principles, become dry, and turn again at the least contact with the air. If they are very bad, and their alcoholic strength much enfeebled, they had better be made into vinegar.

Machard’s Treatment.—Machard says that the most successful treatment for sour wine employed by him, is that founded upon the affinity of vegetable substances for acids, and that he has succeeded beyond his hopes in completely removing the acid from a wine which was so sour that it could not be drank without seriously disagreeing with the person drinking it. This is his method of proceeding.

He formed a long chaplet, six feet or so in length, by cutting carrots into short, thin pieces, and stringing them on a cord. This he suspended in the wine through the bung for six weeks, and at the end of the time he did not find the least trace of acetic acid, thereby accomplishing what he had for a long time in vain attempted. He says that this is the only treatment that succeeded with him, and he confidently recommends it to others. But he advises that the carrots be left in the wine at least a month and a half, protecting the wine from the air. And he says that there is no danger of injuring the wine by long contact with the carrots, or by using a large quantity of them.