12. Filtration
Filtration By filtration, the gluten or yeast is separated from the juice of the grape. While the juice will pass through the filtering implements, the gluten will not, and, being thus separated, the necessary conditions of fermentation are destroyed.
Donavan, already quoted, states that, “if the juice be filtered and deprived of its gluten or ferment, the production of alcohol is impossible.” Dr. Ure says, as previously stated, that fermentation may be prevented “by the separation of the yeast either by the filter or by subsidence.” The ancient writers, when speaking of the removal of the vim, vi, vires, that is, the potency or fermentable power of the wine, use the following strong words: eunuchrum, castratum, effoeminatum—thus expressing the thoroughness of the process by which all fermentation was destroyed—Anti-Bacchus, p. 224. Plutarch, born a.d. 60, in his Symposium, says: “Wine is rendered old or feeble in strength when it is frequently filtered. The strength or spirit being thus excluded, the wine neither inflames the brain nor infests the mind and the passions, and is much more pleasant to drink”—Bible Com. p. 278. In this passage, we are instructed that the filter was not a mere strainer, such as the milkmaid uses, but was such an instrument as forced the elements of the grape-juice asunder, separating the gluten, and thus taking away the strength, the spirit, which inflames the head and infests the passions.
Pliny, liber xxiii. cap. 24, says: “Utilissimum (vinum) omnibus sacco viribus fractis. The most useful wine has all its force or strength broken by the filter”—Bible Commentary, pp. 168 and 211.
Others hold that the true rendering is: “For all the sick, the wine is most useful when its forces have been broken by the strainer.” This does not relieve the difficulty; for, when the forces of the wine, which is the alcohol, have been broken (fractis, from frango, to break in pieces, to dash to pieces), what then is left but the pure juice? The next sentence of Pliny clearly states that the vires or forces of the wine are produced by fermentation: “Meminerimus succum esse qui fervendo vires e musto sibi fecerit.” “We must bear in mind that there is a succus, which, by fermenting, would make to itself a vires out of the must.” The succus represents the gluten or yeast, the detention of which in the filter would effectually prevent all fermentation—Nott, Edition by F.R. Lees, p. 211. The strainer (saccus) separates the gluten; for in no other way can it break the forces, the fermenting power. Smith, in his Greek and Roman Antiquities, says: “The use of the saccus (filter), it was believed, diminished the strength of the liquor. For this reason it was employed by the dissipated in order that they might be able to swallow a greater quantity without becoming intoxicated.” Again: “A great quantity of sweet wines was manufactured by checking the fermentation.” Prof. C. Anthon makes a similar statement in his Dictionary of Greek and Roman Antiquities.
Again, Pliny: “Inveterari vina saccisque castrari.” “Wines were rendered old and castrated or deprived of all their vigor by filtering”—Nott, London Ed.
“Ut plus capiamus vini sacco frangimur vires;” that we may drink the more wine, we break in pieces, vires, the strength or spirit, sacco, by the filter. He adds that they practised various incentives to increase their thirst—Bible Commentary, p. 168. On the words of Horace, “vina liques,” Car. lib. i. ode ii., the Delphin Notes says: “Be careful to prepare for yourself wine percolated and defecated by the filter, and thus rendered sweet and more in accordance to nature and a female taste.” Again: “The ancients filtered and defecated their must repeatedly before they could have fermented; and thus the faeces which nourish the strength of the wine being taken away, they rendered the wine itself more liquid, weaker, lighter and sweeter, and more pleasant to drink”—Bible Commentary, p. 168, and Nott, London Edition, p. 79.
Captain Treat, in 1845, wrote: “When on the south coast of Italy, last Christmas, I enquired particularly about the wines in common use, and found that those esteemed the best were sweet and unintoxicating. The boiled juice of the grape is in common use in Sicily. The Calabrians keep their intoxicating and unintoxicating wines in separate apartments. The bottles were generally marked. From enquiries, I found that unfermented wines were esteemed the most. It was drunk mixed with water. Great pains were taken in the vintage season to have a good stock of it laid by. The grape-juice was filtered two or three times, and then bottled, and some put in casks and buried in the earth—some kept in water (to prevent fermentation)—Dr. Lees’ Works, vol. ii. p. 144.
Gluten is as indispensable to fermentation, whether vinous or acetous, as is sugar. It is a most insoluble body until it comes in contact with the oxygen of the atmosphere; but by frequent filtering of the newly-pressed juice, the gluten is separated from the juice, and thus fermentation prevented.