The cork crisis: Why screw top bottles are the future

Every body knows that no product of the arts varies so much as wine; that different countries, and sometimes the different provinces of the same country, produce different wines.

These differences, no doubt, must be attributed chiefly to the climate in which the vineyard is situated—to its culture—the quantity of sugar contained in the grape juice—the manufacture of the wine; or the mode of suffering its fermentation to be accomplished.

If the grapes be gathered unripe, the wine abounds with acid; but if the fruit be gathered ripe, the wine will be rich. When the proportion of sugar in the grape is sufficient, and the fermentation complete, the wine is perfect and generous.

If the quantity of sugar be too large, part of it remains undecomposed, as the fermentation is languid, and the wine is sweet and luscious; if, on the contrary, it contains, even when full ripe, only a small portion of sugar, the wine is thin and weak; and if it be bottled before the fermentation be completed, part of the sugar remains undecomposed, the fermentation will go on slowly in the bottle, and, on drawing the cork, the wine sparkles in the glass; as, for example, Champagne. Such wines are not sufficiently mature. When the must is separated from the husk of the red grape before it is fermented, the wine has little or no colour: these are called white wines.

If, on the contrary, the husks are allowed to remain in the must while the fermentation is going on, the alcohol dissolves the colouring matter of the husks, and the wine is coloured: such are called redwines. Hence white wines are often prepared from [Pg 91]red grapes, the liquor being drawn off before it has acquired the red colour; for the skin of the grape only gives the colour. Besides in these principal circumstances, wines vary much in flavour.

All wines contain one common and identical principle, from which their similar effects are produced; namely, brandy or alcohol.

It is especially by the different proportions of brandy contained in wines, that they differ most from one another. When wine is distilled, the alcohol readily separates. The spirit thus obtained is well known under the name of brandy.

All wines contain also a free acid; hence they turn blue tincture of cabbage, red. The acid found in the greatest abundance in grape wines, is tartaric acid. Every wine contains likewise a portion of super-tartrate of potash, and extractive matter, derived from the juice of the grape. These substances deposit slowly in the vessel in which they are kept. To this is owing the improvement of wine from age. Those wines which effervesce or froth, when poured into a glass, contain also carbonic acid, to which their briskness is owing. The peculiar flavour and odour of different kinds of wines probably depend upon the presence of a volatile oil, so small in quantity that it cannot be separated.

The strength of all wines depends upon the quantity of alcohol or brandy which they contain. Mr. Brande, and Gay-Lussac, have proved, by very decisive experiments, that all wines contain brandy or alcohol ready formed. The following is the process discovered by Mr. Brande, for ascertaining the quantity of spirit, or brandy, contained in different sorts of wine.

The great deficiency in these wines, independent of the flavour, which chiefly originates, not from the juice, but from the seeds and husks of the fruits, is the excess of acid, which is but imperfectly concealed by the addition of sugar. This is owing, [Pg 97]chiefly, as Dr. Macculloch remarks, to the tartaric acid existing in the grape juice in the state of super-tartrate of potash, which is in part decomposed during the fermentation, and the rest becomes gradually precipitated; whilst the malic acid exists in the currant and gooseberry juice in the form of malate of potash; which salt does not appear to suffer a decomposition during the fermentation of the wine; and, by its greater solubility, is retained in the wine. Hence Dr. Macculloch recommends the addition of super-tartrate of potash, in the manufacture of British wines. They also contain a much larger proportion of mucilage than wines made from grapes. The juice of the gooseberry contains some portion of tartaric acid; hence it is better suited for the production of what is called English Champagne, than any other fruit of this country.

I have been assured by several bakers, on whose testimony I can rely, that the small profit attached to the bakers' trade, [Pg 100]and the bad quality of the flour, induces the generality of the London bakers to use alum in the making of their bread.

The smallest quantity of alum that can be employed with effect to produce a white, light, and porous bread, from an inferior kind of flour, I have my own baker's authority to state, is from three to four ounces to a sack of flour, weighing 240 pounds. The alum is either mixed well in the form of powder, with a quantity of flour previously made into a liquid paste with water, and then incorporated with the dough; or the alum is dissolved in the water employed for mixing up the whole quantity of the flour for making the dough.

Let us suppose that the baker intends to convert five bushels, or a sack of flour, into loaves with the least adulteration practised. He pours the flour into the kneading trough, and sifts it through a fine wire sieve, which makes it lie very light, and serves to separate any impurities with which the flour may be mixed. Two ounces of alum are then dissolved in about a quart of boiling water, and the solution poured into the seasoning-tub. Four or five pounds of salt are likewise put into the tub, and a pailful of hot-water. When this mixture has cooled down to the temperature of about [Pg 101]84°, three or four pints of yeast are added; the whole is mixed, strained through the seasoning sieve, emptied into a hole in the flour, and mixed up with the requisite portion of it to the consistence of a thick batter. Some dry flour is then sprinkled over the top, and it is covered up with cloths.