The result of a complete fermentation is a dry wine; to produce which, the elements must all be nicely balanced, and the process conducted under favourable circumstances, with respect to temperature, tunning, stopping down, &c.
Two opposite practices prevail, in the manufacture of the same sort of wine; some wine-makers boiling the juices before fermentation, others conducting the whole process without boiling: the propriety or impropriety of these practices depends upon the quality of the juices to be vinified. Extractive matter is partially coagulable by heat; boiling therefore, by causing this matter to separate and to be deposited, tends to the production of a sweet wine. The extractive matter may also be precipitated by sulphuric acid gas, (burning in the cask a brimstone match as hereafter directed,) or by sulphuric acid itself, with which the soluble leaven forms an insoluble compound. Hence where the extractive matter is in excess, and where there is danger of fermentation going on too rapidly, boiling or sulphuring will be useful both to the wine and cider-maker, in checking or preventing fermentation. The superfluous extract thrown up in the course of fermentation as yeast, or deposited as lees, will, if remixed with the liquor, have the effect of continuing the fermentation: hence the utility of racking and fining, where it is in excess; and of re-union, where it is deficient. Artificial leaven or yeast, which contains the extractive principle in great abundance, affords a supply to those juices which are deficient in it, and without which they will not ferment. Natural leaven (i. e. extractive matter) is soluble in cold water, artificial leaven is not: during fermentation, therefore, the latter is always thrown off; so also is the greater part of the former, if the process be well conducted.
Most of the fruits of this country abound in malic acid; those that possess only a moderate quantity of it, however, afford excellent wine with the addition of sugar only; still better wine may be obtained by the further addition of the acid of tartar. Where the malic acid prevails so abundantly as to make its neutralization desirable. Dr. McCulloch, (to whom I am indebted for much of the information contained in this chapter,) recommends the coating of the insides of the fermenting vats with a white wash of hot caustic lime. I have neutralized the malic acid, by putting into the cask, after the sensible fermentation has been completed, about a pound of egg shells to every sixty gallons of wine.
The acid of tartar increases the fermenting power of fluids: half-ripe fruits possess it in greatest abundance; hence the vivacity of champagne and green gooseberry wine. It is most conveniently used in the state of supertartrate of potash or common cream of tartar: the common rough tartar is in some respects preferable, as its admixture of yeast assists in perfecting the fermentation.
All vegetables contain more or less of extractive matter; those that possess little may be assisted in their fermentation, by that process being conducted in wooden vessels, wood supplying the extractive principle to the liquor; the same juices therefore which would ferment very well in wood, would scarcely ferment at all in glass or earthenware.
The extractive matter and the sugar are seldom completely destroyed in any wines; the existence of the former is evinced, by the skinny matter frequently deposited upon the insides of the wine-bottles; the latter may be detected, by a nice palate, in the very driest of our wines; its predominance indicates an inferior wine.
From the preceding observations, my readers have probably anticipated my opinion of honey, in wine-making. I regard it merely as a substitute for sugar; and to those who approve of its flavour I recommend the following directions, which I have successfully followed for several years, having my home-made wines enriched with a considerable portion of foreign flavour.—Dissolve an ounce of cream of tartar in five gallons of boiling water; pour the solution off clear upon twenty pounds of fine honey, boil them together and remove the scum as it rises. Towards the end of the boiling, add an ounce of fine hops; about ten minutes afterwards, put the liquor into a tub to cool; when reduced to the temperature of about 60° Fahrenheit, add a slice of bread toasted and smeared over with a very little yeast; the smaller the quantity the better, for yeast invariably spoils the flavour of wines, and where there is a sufficiency of extractive matter in the ingredients employed, it should never be introduced. The liquor should now stand, and be stirred occasionally, till it carries a head, when it should be tunned and the cask filled up from time to time from the reserve, till the fermentation has nearly subsided. It should now be bunged down, leaving open a small peg-hole; in a few days this may also be closed, and in about twelve months the wine will be fit to bottle.
Many makers of both wine and cider have been unconsciously benefited from the acquisition of tartar by their liquor; it being a frequent practice to tun into an empty foreign wine cask, whose incrusted sides have supplied their wine or their cider with a portion of that necessary ingredient for perfect vinification.
It is a practice with some to add spices to their Mead during the fermentation, such as ginger, cloves, mace, rosemary, lemon-peel, &c. This is bad œconomy; a much smaller quantity will communicate the required flavour if the addition be made after the fermentation has ceased.