Under cookery I include those changes which may be obtained by simply exposing the wine to the action of the temperature of an ordinary cellar, or the higher temperature of ‘Pasteuring,’ to be presently described.
In the youthful days of chemistry the first of these methods of cookery was the only one available, and wine was kept by wine-merchants with purely commercial intent for a considerable number of years.
A little reflection will show that this simple and original cookery was very expensive, sufficiently so to legitimately explain the rise in market value from tenpence to five shillings or more per bottle.
Wine-merchants require a respectable profit on the capital they invest in their business—at least ten per cent. per annum on the prime cost of the wine laid down. Then there is the rental of cellars and offices, the establishment expenses—such as wages, sampling, sending out, advertising, losses by bad debts, &c.—to be added. The capital lying dead in the cellar demands compound interest. At ten per cent. the principal doubles in about seven and one-third years. Calling it seven years, to allow very meagrely for establishment expenses, we get the following result:
| £ | s. | d. | ||||||
| When | 7 | years old the | tenpenny | wine is worth | 0 | 1 | 8 | per bottle. |
| ” | 14 | ” | ” | ” | 0 | 3 | 4 | ” |
| ” | 21 | ” | ” | ” | 0 | 6 | 8 | ” |
| ” | 28 | ” | ” | ” | 0 | 13 | 4 | ” |
| ” | 35 | ” | ” | ” | 1 | 6 | 8 | ” |
Here, then, we have a fair commercial explanation of the high prices of old-fashioned old wines; or of what I may now call the traditional value of wine.
Of course, this is less when a man lays down his own wine in his own cellar, in obedience to the maxim, ‘Lay down good port in the days of your youth, and when you are old your friends will not forsake you.’ He may be satisfied with a much smaller rate of interest than the man engaged in business fairly demands. Still, when wine thus aged was thrown into the market, it competed with commercially cellared wine, and obtained remarkable prices, especially as it has a special value for ‘blending’ purposes, i.e. for mixing with newer wines and infecting them with its own senility.
But why do I say that now such values are traditional? Simply because the progress of chemistry has shown us how the changes resulting from years of cellarage may be effected by scientific cookery in a few hours or days. We are indebted to Pasteur for the most legitimate—I might say the only legitimate—method of doing this. The process is accordingly called ‘Pasteuring.’ It consists in simply heating the wine to the temperature of 60° C. = 140° Fahr., the temperature at which, as will be remembered, the visible changes in the cookery of animal food commences. It is worthy of note that this is also the exact temperature at which diastase acts most powerfully in converting starch into dextrin. Pasteuring is a process demanding considerable skill; no portion of the wine during its cookery must be raised above 140°, yet all must reach it; nor must it be exposed to the air.
The apparatus designed by Rossignol is one of the best suited for this purpose. It is a large metallic vat or boiler with air-tight cover and a false bottom, from which rises a trumpet-shaped tube through the middle of the vat, and passing through an air-tight fitting in the cover. The chamber formed by the false bottom is filled with water by means of this tube, the object being to prevent the wine at the lower part from being heated directly by the fire which is below the water chamber. A thermometer is also inserted air-tight in the lid, with its bulb half-way down the vat. To allow for expansion a tube is similarly fitted into the lid. This is bent syphon-like, and its lower end dipped into a flask containing wine or water, so that air or vapour may escape and bubble through, but none enter. Even in drawing off from the vat the wine is not allowed to flow through the air, but is conveyed by a pipe which bends down, and dips to the bottom of the barrel. The apparatus is bulky and expensive.
If heated with exposure to air, the wine acquires a flavour easily recognised as the ‘goût de cuit,’ or flavour of cooking. When Pasteur’s method is properly conducted the only changes effected are those which would be otherwise produced by age. I have heard of many failures made by English wine-merchants in their attempts at Pasteuring, and am not at all surprised, seeing how secretly and clumsily these attempts have been made.