Chaps. 18-25.

Chap. 18. (16.)—The Uses of the Wild Vine. What Juices Are Naturally the Coldest of All.

I am not surprised, then, that for these many ages there have been invented almost innumerable varieties of artificial wines, of which I shall now make some mention; they are all of them employed for medicinal purposes. We have already stated in a former Book how omphacium, [B. xii. c..] which is used for unguents, is made. The liquor known as “œnanthinum” is made from the wild vine, [Or “labrusca.” “Œnanthinum” means “made of vine flowers.” The wild vine is not a distinct species from the cultivated vine: it is only a variety of it, known in botany as the Vitis silvestris labrusca of Tournefort. Fée thinks that as the must could only be used in autumn, when the wild vine was not flowering, the flowers of it must have been dried.] two pounds of the flowers of which are steeped in a cadus of must, and are then changed at the end of thirty days. In addition to this, the root and the husks of the grapes are employed in dressing leather. The grapes, too, a little after the blossom has gone off, are singularly efficacious as a specific for cooling the feverish heat of the body in certain maladies, being, it is said, of a nature remarkable for extreme coldness. A portion of these grapes wither away, in consequence of the heat, before the rest, which are thence called solstitial [“Solstitiales.” Because they withstand the heat of the solstice. Marcellus Empiricus calls them “caniculati,” because they bear the heat of the Dog-star.] grapes; indeed, the whole of them never attain maturity; if one of these grapes, in an unripe state, is given to a barn-door fowl to eat, it is productive of a dislike to grapes for the future. [Fée remarks that this assertion is quite erroneous.]

Chap. 19.—Sixty-Six Varieties of Artificial Wine.

The first of the artificial wines has wine for its basis; it is called “adynamon,” [From the Greek, meaning “without strength.” The mixture, Fée remarks, would appear to be neither potable nor wholesome.] and is made in the following manner. Twenty sextarii of white must are boiled down with half that quantity of water, until the amount of the water is lost by evaporation. Some persons mix with the must ten sextarii of sea-water and an equal quantity of rain-water, and leave the whole to evaporate in the sun for forty days. This beverage is given to invalids to whom it is apprehended that wine may prove injurious.

The next kind of artificial wine is that made of the ripe grain of millet; [See B. xviii. c. 24. A kind of beer might be made with it, Fée says; but this mixture must have been very unpalatable.] a pound and a quarter of it with the straw is steeped in two congii of must, and the mixture is poured off at the end of six months. We have already stated [See B. xiii. c..] how various kinds of wine are made from the tree, the shrub, and the herb, respectively known as the lotus.

From fruit, too, the following wines are made, to the list of which we shall only add some necessary explanations:—First of all, we find the fruit of the palm [A vinous drink may be made in the manner here stated; but the palm-wine of the peoples of Asia and Africa is only made of the fermented sap of the tree. See B. xiii. c..] employed for this purpose by the Parthians as well as the Indians, and, indeed, throughout all the countries of the East. A modius of the kind of ripe date called “chydææ” [He says “caryotæ,” and not chydææ, in B. xiii. c.. The modius was something more than our peck.] is added to three congii of water, and after being steeped for some time, they are subjected to pressure. Sycites [From the Greek σύκη, a “fig.” This wine was made, Fée thinks, from the produce of some variety of the sycamore. See B. xiii. c..] is a preparation similarly made from figs: some persons call it “palmiprimum,” [“Prime palm” apparently.] others, again, “catorchites:” if sweetness is not the maker’s object, instead of water there is added the same quantity of husk juice [Tortivum, probably: the second squeezing.] of grapes. Of the Cyprian fig [See B. xiii. c..] a very excellent vinegar, too, is made, and of that of Alexandria [See B. xiii. c..] a still superior.

A wine is made, too, of the pods of the Syrian carob, [See B. xiii. c..] of pears, and of all kinds of apples. That known as “rhoites” [From ῥόα, a “pomegranate.”] is made from pomegranates, and other varieties are prepared from cornels, medlars, sorb apples, dried mulberries, and pine-nuts [Dioscorides calls it “strobilites.” Fée says that they could be of no service in producing a vinous drink.] these last are left to steep in must, and are then pressed; the others produce a sweet liquor of themselves. We shall have occasion before long to show how Cato [See B. xv. c..] has pointed out the method of making myrtites: [Or “myrtle wine.”] the Greeks, however, adopt a different method in making it. They first boil tender sprigs of myrtle with the leaves on in white must, and after pounding them, boil down one pound of the mixture in three congii of must, until it is reduced to a couple of congii. The beverage that is prepared in this manner with the berries of wild myrtle is known as “myrtidanum;” [Myrtle will not make a wine, but simply a medicament, in which wine is the menstruum.] it will stain the hands.

Among the garden plants we find wines made of the following kinds: the radish, asparagus, cunila, origanum, parsley-seed, abrotonum, [Artemisia abrotonum of Linnæus.] wild mint, rue, [Ruta graveolens of Linnæus.] catmint, [Nepeta cataria of Linnæus.] wild thyme, [Thymus serpyllum of Linnæus.] and horehound. [Marrubium vulgare of Linnæus.] A couple of handfuls of these ingredients are put into a cadus of must, as also one sextarius of sapa, [Grape-juice boiled down to one-third.] and half a sextarius of sea-water. A wine is made of the naphew [Brassica napus of Linnæus.] turnip by adding two drachms of naphew to two sextarii of must. A wine is made also from the roots of squills. [Scilla marina of Linnæus.] Among the flowers, that of the rose furnishes a wine: the leaves are put in a linen cloth and then pounded, after which they are thrown into must with a small weight attached to make them sink to the bottom, the proportion being forty drachms of leaves to twenty sextarii of must; the vessel in which it is kept must not be opened before the end of three months. A wine, too, is made of Gallic nard, [Nardus Gallicus, or Valeriana Celtica of Linnæus. See B. xii. c..] and another kind of the wild [Nardus silvestris or baccaris.] variety of that plant.

I find, also, that various kinds of aromatites [Aromatic wines.] are prepared, differing but very little in their mode of composition from that of the unguents, being made in the first instance, as I have already stated, [In c. of this Book.] of myrrh, and then at a later period of Celtic nard, [Valeriana Celtica.] calamus, and aspalathus, [Convolvulus scoparius of Linnæus.] of which cakes are made, and are then thrown into either must or sweet wine. Others, again, make these wines of calamus, scented rush, [Andropogon schœnanthus of Linnæus.] costus, [Costus Indicus of Linnæus.] Syrian nard, [Andropogon nardus of Linnæus.] amomum, [See B. xiii. c..] cassia, [See B. xii. c..] cinnamon, saffron, [Crocus sativus of Linnæus.] palm-dates, and foal-foot, [Asarum Europæum of Linnæus.] all of which are made up into cakes in a similar manner. Other persons, again, put half a pound of nard and malobathrum [See B. xii. c..] to two congii of must; and it is in this manner that at the present day, with the addition of pepper and honey, the wines are made by some known as confection wines, [Condita.] and by others as peppered [Piperata.] wines. We find mention made of nectarites also, a beverage extracted from a herb known to some as “helenion,” [Inula helenium of Linnæus. See B. xxi. c. 91.] to others as “Medica,” [Medicago sativa of Linnæus.] and to others, again, as symphyton, [Symphytum officinale of Linnæus, being all different varieties.] Idæa, Orestion, or nectaria, the root of which is added in the proportion of forty drachms to six sextarii of must, being first similarly placed in a linen cloth.

As to other kinds of herbs, we find wormwood wine, [“Absinthites” made of the Artemisia Pontica of Linnæus. A medicinal wine is still prepared with wormwood; and “apsinthe,” a liqueur much esteemed in France, is made from it.] made of Pontic wormwood in the proportion of one pound to forty sextarii of must, which is then boiled down until it is reduced to one third, or else of slips of wormwood put in wine. In a similar manner, hyssop wine [Hyssopites.] is made of Cilician hyssop, [Hyssopites officinalis of Linnæus.] by adding three ounces of it to two congii of must, or else by pounding three ounces of hyssop, and adding them to one congius of must. Both of these wines may be made also in another method, by sowing these plants around the roots of vines. It is in this manner, too, that Cato tells us how to make hellebore [Helleborites.] wine from black hellebore; and a similar method is used for making scammony [Scammonites.] wine. The vine has a remarkable propensity [Fée says that this is not the fact; and queries whether the vulgar notion still entertained on this subject, may not be traced up to our author. It is a not uncommon belief that roses smell all the sweeter if onions are planted near them.] of contracting the flavour of any plant that may happen to be growing near it; and hence it is that in the marshy lands of Patavium, the grape has the peculiar flavour of the willow. So, in like manner, we find at Thasos hellebore planted among the vines, or else wild cucumber, or scammony; the wine that is produced from these vines is known by the name of “phthorium,” it being productive of abortion.

Wines are made, too, of other herbs, the nature of which will be mentioned in their respective places, the stœchas [Lavendula stœchas of Linnæus. See B. xxvii. c. 107.] for instance, the root of gentian, [Gentiana lutea of Linnæus. See B. xxv. c. 34. Gentian wine is still made.] tragoriganum, [Thymus tragoriganum of Linnæus. See B. xx. c. 68.] dittany, [Origanum dictamnus of Linnæus. See B. xxv. c. 63.] foal-foot, [Asarum Europæum of Linnæus. See B. xii. c..] daucus, [Query, if not carrot? See B. xxv. c. 64.] elelisphacus, [A variety of salvia or sage: it will be mentioned again, further on.] panax, [Laserpitium hirsutum of Linnæus. See B. xxv. cc. 11, 12, and 13.] acorus, [Acorus calamus of Linnæus. See B. xxv. c. 100.] conyza, [See B. xxi. c. 32.] thyme, [See B. xxi. c. 31.] mandragore, [Atrapora mandragora of Linnæus. This wine would act as a narcotic poison, it would appear.] and sweet rush. [Andropogon schœnanthus of Linnæus. See B. xxi. c. 72.] We find the names mentioned, also, of scyzinum, [The origin and meaning of these names are unknown.] itæomelis, and lectisphagites, compounds of which the receipt is now lost.

The wines that are made from the shrubs are mostly extracted from the two kinds of cedar, [See B. xii. c.. Juniperus Lycia, and Juniperus Phœnicea of Linnæus.] the cypress, [Cupressus sempervirens of Linnæus.] the laurel, [Laurus nobilis of Linnæus. See B. xv. c..] the juniper, [Juniperus communis of Linnæus.] the terebinth, [See B. xiii. c.. The Pistacia terebinthus of Linnæus.] and in Gaul the lentisk. [See B. xii. c.. The Pistacia lentiscus of Linnæus.] To make these wines, they boil either the berries or the new wood of the shrub in must. They employ, also, the wood of the dwarf olive, [“Chamelæa.” The Granium Cnidium, Daphne Cnidium, and Daphne cneorum of Linnæus. See B. xiii. c.. Venomous plants, which, taken internally, would be productive of dangerous results.] the ground-pine, [Chamæpitrys. The Teucrium chamæpitrys of Linnæus. See B. xxv. c. 20.] and the germander [Chamædrys. The Teucrium chamædrys of Linnæus. See B. xxiv. c. 80. Dioscorides mentions most of these so-called wines.] for a similar purpose, adding at the same time ten drachms of the flower to a congius of must.

Chap. 20. (17.)—Hydromeli, or Melicraton.

There is a wine also made solely of honey and water. [Mead, or metheglin. See B. xxii. c. 51.] For this purpose it is recommended that rain-water [There is no ground, Fée says, for this recommendation.] should be kept for a period of five years. Those who shew greater skill, content themselves with taking the water just after it has fallen, and boiling it down to one third, to which they then add one third in quantity of old honey, and keep the mixture exposed to the rays of a hot sun [Stoves are now used for this purpose.] for forty days after the rising of the Dog-star; others, however, rack it off in the course of ten days, and tightly cork the vessels in which it is kept. This beverage is known as “hydromeli,” and with age acquires the flavour of wine. It is nowhere more highly esteemed than in Phrygia. [“Hydromēlum,” on the other hand, made of water and apples, was the same as our modern cider.]

Chap. 21.—Oxymeli.

Vinegar [See B. xxiii. c. 9.] even has been mixed with honey; nothing, in fact, has been left untried by man. To this mixture the name of oxymeli has been given; it is compounded of ten pounds of honey, five semi-sextarii of old vinegar, one pound of sea-salt, and five sextarii of rain-water. This is boiled gently till the mixture has bubbled in the pot some ten times, [“Subfervefactis.” “Just come on the boil.”] after which it is drawn off, and kept till it is old; [The oxymel of modern times contains no salt, and is only used as a medicament.] all these wines, however, are condemned [As drinks, no doubt; and with good reason, as to most of them.] by Themison, an author of high authority. And really, by Hercules! the use of them does appear to be somewhat forced, [Coactus.] unless, indeed, we are ready to maintain that these aromatic wines are so many compounds taught us by Nature, as well as those that are manufactured of perfumes, or that shrubs and plants have been generated only for the purpose of being swallowed in drink. However, all these particulars, when known, are curious and interesting, and show how successfully the human intellect has pried into every secret.

None of these wines, however, will keep beyond a year, [Our medicinal wines will mostly keep longer than this, owing probably to the difference in the mode of making the real wines that form their basis.] with the sole exception of those which we have spoken of as requiring age; many of these, indeed, there can be no doubt, do not improve after being kept so little as thirty days.

Chap. 22. (18.)—Twelve Kinds of Wine with Miraculous Properties.

There are some miraculous properties, too, in certain wines. It is said that in Arcadia there is a wine grown which is productive of fruitfulness [There is little doubt that this is fabulous: wine taken in excess, we know, is productive of loss of the senses, frenzy in the shape of delirium tremens.] in women, and of madness in men; while in Achaia, and more especially in the vicinity of Carynia, there is a wine which causes abortion; an effect which is equally produced if a woman in a state of pregnancy happens only to eat a grape of the vine from which it is grown, although in taste it is in no way different from ordinary grapes: again, it is confidently asserted that those who drink the wine of Trœzen never bear children. Thasos, it is said, produces two varieties of wine with quite opposite properties. By one kind sleep is produced, [This is not unlikely; for, as Fée remarks, the red wines, containing a large proportion of alcohol, act upon the brain and promote sleep, while the white wines, charged with carbonic gas, are productive of wakefulness.] by the other it is prevented. There is also in the same island a vine known as the “theriaca,” [Or healing vine. See B. xxiii. c. 11.] the wine and grapes of which are a cure for the bites of serpents. The libanian vine [“Libanios.” Probably incense was put in this wine, to produce the flavour.] also produces a wine with the smell of frankincense, with which they make libations to the gods, while, on the other hand, the produce of that known as “aspendios,” [From ἀ, “not,” and σπένδειν, “to make libation.”] is banished from all the altars: it is said, too, that this last vine is never touched by any bird.

The Egyptians call by the name of “Thasian,” [See c. of this Book. It was introduced, probably, from Thasos.] a certain grape of that country, remarkable for its sweetness and its laxative qualities. On the other hand, there is in Lycia a certain grape which proves astringent to the stomach when relaxed. Egypt has a wine, too, known as “ecbolas,” [From ἐκβάλλω, “to eject.”] which is productive of abortion. There are some wines, which at the rising of the Dog-star change their nature in the wine-lofts [Apothecis.] where they are kept, and afterwards recover [He alludes to the working of wines in periods of extreme heat; also in the spring.] their original quality. The same is the case, too, with wines when carried across the seas: those that are able to withstand the motion of the waves, appear afterwards to be twice as old [Of our modern wines, Madeira and Bourdeaux improve by being carried across sea. Burgundy, if any thing, deteriorates, by the diminution of its bouquet.] as they really are.

Chap. 23. (19.)—What Wines It Is Not Lawful to Use in the Sacred Rites.

As religion is the great basis of the ordinary usages of life, I shall here remark that it is considered improper to offer libations to the gods with any wines which are the produce of an unpruned vine, or of one that has been struck by lightning, or near to which a dead man has been hung, or of grapes that have been trodden out by sore feet, or made of must from husks that have been cut, [After the grapes had been trodden and pressed, the husks were taken out and their edges cut, and then again subjected to pressure: the result was known as “tortivum,” or “circumcisivum,” a wine of very inferior quality.] or from grapes that have been polluted by the fall of any unclean thing upon them. The Greek wines are excluded also from the sacred ministrations, because they contain a portion of water.

The vine itself is sometimes eaten; the tops of the shoots [He alludes to the young shoots, which have an agreeable acidity, owing to acetic and tartaric acids.] are taken off and boiled, and are then pickled in vinegar [Acetic acid; the result, no doubt, of the faulty mode of manufacture universally prevalent; their wines contained evidently but little alcohol.] and brine.

Chap. 24.—How Must Is Usually Prepared.

It will be as well now to make some mention of the methods used in preparing wines; indeed, several of the Greeks have written separate treatises on this subject, and have made a complete art of it, such, for instance, as Euphronius, Aristomachus, Commiades, and Hicesius. The people of Africa are in the habit of neutralizing such acidity [See B. xxiii. c. 24, and B. xxxvi. c. 48.] as may be found with gypsum, and in some parts with lime. The people of Greece, on the other hand, impart briskness to their wines when too flat, with potters’ earth, pounded marble, salt, or sea-water; while in Italy, again, brown pitch is used for that purpose in some parts, and it is the universal practice both there as well as in the adjoining provinces to season their new wines with resin: sometimes, too, they season them with old wine-lees or vinegar. [A process very likely, as Fée remarks, to turn the wines speedily to vinegar.] They make various medicaments, also, for this purpose with the must itself. They boil it down till it becomes quite sweet, and has lost a considerable portion of its strength; though thus prepared, they say it will never last beyond a single year. In some places they boil down the must till it becomes sapa, [Down to one-third. This practice of using boiled grape-juice as a seasoning, is still followed in Spain in making some of the liqueurs; but it is not generally recommended.] and then mix it with their wines for the purpose of modifying their harshness. Both for these kinds of wines, as, indeed, all others, they always employ vessels which have themselves received an inner coat of pitch; the method of preparing them will be set forth in a succeeding Book. [B. xvi. c..]

Chap. 25. (20.)—Pitch and Resin.

Of the trees from which pitch and resin distil, there are some which grow in the East, and others in Europe: the province of Asia, [Asia Minor, namely.] which lies between the two, has also some of both kinds. In the East, the very best commodity of this kind, and of the finest quality, is that produced by the terebinth, [B. xiii. c..] and, next to it, that from the lentisk, [B. xii. c..] which is also known as the mastich. The next in quality to these is the juice of the cypress, [It produces but a very minute quantity of resin, which is no longer an article of commerce.] being of a more acrid flavour than any other. All the above juices are liquid and of a resinous nature only, but that of the cedar [See B. xiii. c., and B. xvi. c.. Not the cedar of Lebanon, probably, which only gives a very small quantity of resin, but one of the junipers.] is comparatively thick, and of a proper consistency for making pitch. The Arabian resin [Fée suggests that this may have been the resin of the Arabian terebinth.] is of a pale colour, has an acrid smell, and its fumes are stifling to those employed in boiling it. That of Judæa is of a harder nature, and has a stronger smell than that from the terebinth [See B. xxiv. c. 22.] even. The Syrian [Perhaps from the Pistacia terebinthus of Linnæus.] resin has all the appearance of Attic honey, but that of Cyprus is superior to any other; it is the colour of honey, and is of a soft, fleshy nature. The resin of Colophon [This was made from the terebinth: but the modern resin of Colophon is extracted from varieties of the coniferæ.] is yellower than the other varieties, but when pounded it turns white; it has a stifling smell, for which reason the perfumers do not employ it. That prepared in Asia from the produce of the pitch-tree is very white, and is known by the name of “spagas.”

All the resins are soluble in oil; [See B. xxiv. c. 22.] some persons are of opinion also that potters’ chalk may be so dissolved: [Earths are not soluble in oils.] I feel ashamed [As being a mark of extreme effeminacy.] to avow that the principal esteem in which the resins are held among us is as depilatories for taking the hair off men’s bodies.

The method used for seasoning wines is to sprinkle pitch in the must during the first fermentation, which never lasts beyond nine days at the most, so that a bouquet is imparted to the wine, [The greater the quantity of alcohol, the more resin the wine would be able to hold in solution.] with, in some degree, its own peculiar piquancy of flavour. It is generally considered, that this is done most effectually by the use of raw flower [See B. xvi. c..] of resin, which imparts a considerable degree of briskness to wine: while, on the other hand, it is thought that crapula [“Crapula” properly means head-ache, and what is not uncommonly known as “seediness.” Resined wine was thought to be productive of these effects, and hence obtained the name. This kind of wine was used itself, as we see above, in seasoning the other kinds. Fée remarks, that in reality resins have no such effect as imparting body to weak wines.] itself, if mixed, tends to mitigate the harshness of the wine and subdue its asperity, and when the wine is thin and flat, to give it additional strength and body. It is in Liguria more particularly, and the districts in the vicinity of the Padus, that the utility is recognized of mixing crapula with the must, in doing which the following rule is adopted: with wines of a strong and generous nature they mix a larger quantity, while with those that are poor and thin they use it more sparingly. There are some who would have the wine seasoned with both crapula and flower of resin at the same time. [The whole of this passage is hopelessly corrupt, and we can only guess at the meaning.] Pitch too, when used for this purpose, has much the same properties as must when so employed.

In some places, the must is subject to a spontaneous fermentation a second time: when this unfortunately happens it loses all its flavour, and then receives the name of “vappa,” [We have already stated that “vappa” is properly vinegar, which has been exposed to the air and has lost its flavour. In this fresh chemical change, which he calls a second fermentation, the wine becomes vinegar; and probably in the cases he mentions, for some peculiar reason, its speedy transition to “vappa” could not be arrested.] a word which is applied as an opprobrious appellation even to worthless men of degenerate spirit: in vinegar, on the other hand, notwithstanding its tart and acrid taste, there are very considerable virtues, and without it we should miss many of the comforts [Mixed with water, it was the “posca,” or common drink of the Roman soldiers; and it was used extensively both by Greeks and Romans in their cooking, and at meals.] of civilized life.

In addition to what we have already stated, the treatment and preparation of wines are the object of such remarkable attention, that we find some persons employing ashes, and others gypsum and other substances of which we have already [In c..] spoken, for the purpose of improving its condition: the ashes, [By the mixture of ashes, Fée says, the wines would lose their colour, and have a detestable alkaline flavour.] however, of the shoots of vines or of the wood of the quercus, are in general preferred for this purpose. It is recommended also, to take sea-water far out at sea, and to keep it in reserve, [A perfect absurdity, Fée remarks.] to be employed for this purpose: at all events, it ought to be taken up in the night and during the summer solstice, while the north-east wind is blowing; but if taken at the time of the vintage, it should be boiled before being used.

The pitch most highly esteemed in Italy for preparing vessels for storing wine, is that which comes from Bruttium. It is made from the resin that distils from the pitch-tree; that which is used in Spain is held in but little esteem, being the produce of the wild pine; it is bitter, dry, and of a disagreeable smell. While speaking of the wild trees in a succeeding Book, [B. xvi. cc..] we shall make mention of the different varieties of pitch, and the methods used in preparing it. The defects in resin, besides those which [Bitterness, driness, and a disagreeable smell.] we have already mentioned, are a certain degree of acridity, or a peculiar smoky flavour, while the great fault in pitch is the being over-burnt. The ordinary test of its goodness is a certain luminous appearance when broken to pieces; it ought to stick, too, to the teeth, with a pleasant, tart flavour.

In Asia, the pitch which is most esteemed is that of Mount Ida, in Greece of Pieria; but Virgil [Georg. ii. 498.] gives the preference to the Narycian [See B. iv. c. 12.] pitch. The more careful makers mix with the wine black mastich, which comes from Pontus, [See B. xii. c..] and resembles bitumen in appearance, as also iris [See B. xxi. c. 19.] -root and oil. As to coating the vessels with wax, it has been found that the wine is apt to turn acid: [Bees’ wax, Fée remarks, would not have this effect, but vinegar vessels would.] it is a better plan to put wine in vessels that have held vinegar, than in those which have previously contained sweet wine or mulsum. Cato [De Re Rust. c. 23.] recommends that wines should be got up— concinnari is his word—by putting of lie-ashes boiled down with defrutum, one-fortieth part to the culeus, or else a pound and a half of salt, with pounded marble as well: he makes mention of sulphur also, but only gives the very last place to resin. When the fermentation of the wine is coming to an end, he recommends the addition of the must to which he gives the name of “tortivum,” [The second “squeezings.”] meaning that which is pressed out the very last of all. For the purpose of colouring wine we also add certain substances as a sort of pigment, and these have a tendency to give it a body as well. By such poisonous sophistications is this beverage compelled to suit our tastes, and then we are surprised that it is injurious in its effects!

It is a proof that wine is beginning to turn bad, if a plate of lead, on being put in it, changes its colour. [If the wine is turning to vinegar, subacetate of lead will be formed.]