Kitabı oku: «The Art of Preserving All Kinds of Animal and Vegetable Substances for Several Years, 2nd ed.», sayfa 2

§ II.
Description of my Rooms set apart for carrying on the Process on a large Scale. ⁵

My laboratory consists of four apartments. The first of these is furnished with all kinds of kitchen utensils, stoves, and other apparatus, necessary for dressing the animal substances to be preserved, as well as with a kettle for broth, gravy, &c. containing 180 French pints, raised on brick work. This kettle is provided with a pot to be put within it, pierced with holes like a skimmer, with divisions for holding various kinds of meat and poultry. This pot can be put into and taken out of the kettle with ease. The kettle is provided with a wide cock, to which is fitted, within, a little rose, like that of a watering-pot, covered with a piece of boulting-cloth. In this way I can procure broth or gravy quite clear, and ready to be put into bottles.

The second apartment is appropriated to the preparing of milk, cream, and whey.

The third is used for corking and tying the bottles and vessels, and putting them into bags.

The fourth is furnished with three large copper boilers, placed upon stones raised on brick work. These boilers are all furnished with a stout lid, fitted, to rest upon the vessels within. Each boiler is furnished with a wide cock below, in order to let out the water at a proper time. These large boilers are destined to receive, generally, all the objects intended to be preserved, in order to apply the action of heat to them in a suitable manner; and thus they constitute so many water-baths.⁶

The utensils which furnish the third apartment for the preparatory process consist of

1. Rows of bottle-racks round the room.

2. A reel for the iron wire, to be used for binding the necks of the bottles and other vessels. (Fig. 1.)

3. Shears and pincers for tying on the corks. (Fig. 6.)

4. Machine for twisting the iron-wire after it has been divided and cut to a proper length. (Fig. 2.)

5. Two instruments forming a lever, and used for compressing, and as it were biting the corks. (Fig. 3.)

6. A bottle-boot or block, standing on three legs, and provided with a strong bat for corking. (Fig. 5.)

7. A stool standing on five legs, for tying on the corks. (Fig. 4.)

8. A sufficient quantity of linen bags, for covering the bottles and other vessels.

9. Two stools covered with leather and stuffed with hay, in order to shake the bottles upon them, and in that way force a greater number of peas and other small substances into the bottles.

10. A press for the juice of plants, fruits, and herbs; with pans, vessels, sieves, and every thing else that belongs to it.

Besides my laboratory, consisting of these articles, I have fitted up three apartments.

The first, for preparing vegetables: it is furnished with dressers all round.

The second, for storing up and preparing all kinds of fruit.

The third is a cellar, furnished with bottle racks, for rinsing and setting by the bottles and other vessels, as in a store-house.

I have the precaution to keep the bottles and other vessels I may want, ready rinsed at hand. I am also supplied with an assortment of corks, compressed and bit in the instrument already described. When every preparation is thus made, the process is half done.

The principle by which all alimentary substances are preserved and kept fresh, is invariable in its effects. The result in particular experiments, depends upon the fitness of each individual application of the principle to the substance which is to be preserved, according to its peculiar qualities; but in every case, the exclusion of air is a precaution of the utmost importance to the success of the operation: and in order to deprive alimentary substances of contact with the air, a perfect knowledge of bottles and the vessels to be used, of corks and corking, is requisite.

§ III.
Of Bottles and Vessels

I chose glass, as being the matter most impenetrable by air, and have not ventured to make any experiment with a vessel made of any other substance. The ordinary bottles have generally necks too small and ill made; they are also too weak to resist the blows from the bat and the action of the fire: I, therefore, caused bottles to be made for my especial use, with wider necks, and those necks made with a projecting rim, or ring, on the interior surface, placed below, and resembling, in form, the rim which is at the top of the exterior surface of the necks of bottles. My object was, that when the cork had been forced into the neck of the bottle, three-fourths of its length, in the manner already described, it should be compressed in the middle. In this manner the bottle is perfectly corked on the outside as well as within. It thus opposes an obstacle to the swelling, or expansion, which arises from the operation of heat upon the substance enclosed within the bottle. This mode of forming the neck of the bottle is so much the more indispensable, as I have repeatedly known the swelling to be so strong, as to push out corks of three or four lines in length, though confined by two iron wires crossed. The bottles and vessels should be made of a tough substance [de matière liante], the former having the weight of twenty-five or twenty-six ounces for each litre⁷ that the bottle contains. The glass ought to be of equal thickness in every part, or it is liable to break in the water-bath. The form of the Champagne bottle is most convenient; it is the handsomest as well as the strongest, and is of the best shape for packing up.

§ IV.
Of Corks

Economy in corks is generally very unwise, as in order to save a very trifle in the price of cork, a risk is incurred of losing the valuable commodity it is intended to preserve. As corking is made use of in order to preserve and meliorate certain articles, by depriving them of all contact with the air, too much attention cannot be given to the good quality of the cork, which should be of eighteen or twenty lines in length and of the finest quality. Experience has so fully satisfied me on this point, that I never make use of any but superfine corks: these are, in the end, the cheapest. I further take the precaution of compressing, and, as it were, biting the cork, three-fourths of its length, by means of the instrument already described (fig. 3), beginning at the small end. The cork is rendered more supple; the pores of the cork are brought closer; it is somewhat lengthened, and its thickness is so much diminished at the extremity which is put into the mouth of the bottle, that a large cork may be made to enter a very moderate opening. The action of the heat within the vessel is such, that the cork swells within, and the corking is thus rendered perfect.

§ V.
Of Corking

After what has been just said, the absolute necessity will be apparent of having good bottles, with a projecting rim of equal thickness all round within the neck. Excellent superfine corks are also indispensable, which have been compressed in the instrument three quarters of their length.

Before I cork, I take care that the bottles containing liquor are filled only up to within three inches of the outer rim, lest they should burst from the bubbling and swelling occasioned by the application of heat to the water. When the bottles contain vegetables, fruit, &c. they may be filled up to within two inches of the rim.

I place the full bottle upon the bottle-boot already mentioned, before which I seat myself. This apparatus is to be supplied with a strong wooden bat, a small pot full of water, and a sharp knife, greased with a little suet or soap, for cutting off the tops of the corks, which ought never to be raised much above the head of the bottles. These arrangements being made, I place the bottle-boot between my legs, and taking a cork of fit size, I dip one half of it into the little pot of water, in order to facilitate its entrance; and having wiped the end, I then put it to the mouth of the bottle, at the same time turning it round. I hold it in this position with my left hand, which I keep steady, that the bottle may stand upright. I take the bat in my right hand, in order to drive in the cork by force of blows.

When I find, at the first or second blow of the bat, that the cork has somewhat entered, I take my hand from the cork in order to hold with it the neck of the bottle, which I fix firmly and upright upon the bottle-boot; and by dint of repeated blows, I continue to drive in my cork three-fourths of its length. The quarter of the cork which remains above the bottle, after having refused to yield any further to the redoubled blows of the bat, assures me, in the first place, that the bottle is completely corked, and this same residue serves also to hold the double crossed iron wire which is necessary to bind fast the cork, that it may be able to resist the action of heat on the water-bath. I must repeat again, that too much attention cannot be given to the corking: no circumstance however minute ought to be neglected, in order to effect the rigorous exclusion of the air from the substance to be preserved; air being a most destructive agent, and the one which is most sedulously to be counteracted in the course of the process.⁸

The bottles being well stopped up, I then fasten the cork down with a couple of iron wires crossed: this is an easy operation, and any one can do it, who has once seen it done.

I then put each bottle in a bag of canvass or coarse linen cloth, made for the purpose, sufficiently large to wrap up the whole of the bottle up to the very cork. These bags are made in the shape of a muff, open alike at both ends: one of these ends is drawn with a string running in a gutter, leaving an opening of about the width of a crown piece; the other end is provided with a couple of small strings, in order to tye the bag round the neck of the bottle.

By means of these bags, I can dispense with the use of hay or straw in packing up the bottles in the water-bath; and, whenever any one of them breaks, the fragments are preserved in the bag. I am spared a great deal of trouble and a number of inconveniences which I had formerly to sustain, in picking up the pieces of the bottle out of the straw or hay I then made use of.

After having spoken of bottles, their form and quality; of stoppers, and the length of the fine cork of which they ought to be composed; of the corking and tying; of bags, their form and utility; I proceed to give an idea of vessels with large necks, that is, glass jars, which I make use of for preserving solid and bulky substances, such as poultry, game, meat, fish, &c.

These jars have necks of two, three, or four inches diameter, and are of a larger or small size; like bottles, they are furnished with a projecting rim, not only in order to strengthen the neck, but also for receiving the iron wire destined to bind the corks. I have not yet been able to procure from the glass-houses a similar projecting rim in the interior of the neck of these jars, as I have in that of the bottles. The completely corking up these vessels, is, from this circumstance, rendered more difficult, and demands especial care.

I met with another obstacle in the cork itself, from its thinness (more especially when the cork was very fine), and also from its ascending pores being against the grain. I was therefore obliged to form stoppers of three or four pieces of cork, from twenty to twenty-four lines in length, placed together the way of the grain, the pores of the cork being placed horizontally, by means of isinglass prepared in the following manner.

I melted over the fire four drams of well beaten isinglass, in eight ounces of water: when melted, I caused it to run through fine linen; and then put it again over the fire in order to reduce it to one third of its volume. After which I added an ounce of good full-proof brandy. I then left the whole on the fire till it became reduced to about three ounces. I then put the glue thus prepared in a little pot over live coals, and took care to warm my pieces of cork. I then slightly smeared over the pieces of cork with a brush, in order to glue them together. When the pieces composing the stopper were well fixed and glued together, I then fixed a tight thread to the two extremities of the stopper, in order to keep the pieces together, and let them dry, either in the sun or in a gentle heat for about a fortnight. At the end of this time I took a cork-maker’s knife and cut my stoppers of a proper shape; and having always fitted them to the mouth of the jar, they have never proved defective.

Having corked my jars, and driven in the stopper by means of the bat, the bottles being always placed upright in the bottle-boot, I made use of a compound luting. This luting (communicated to me by Mr. Bardel) is made of quick lime, which is slaked in the air by being sprinkled with water, till it becomes reduced to a powder. The powder to be kept in this state in corked bottles ready for use. This lime mixed with a cheese made of skimmed milk (fromage à la pie), and formed to the thickness of paste, produces a luting which hardens rapidly, and which withstands the heat of boiling water.

I besmear the whole of the outside of the stopper with this luting, and I cover the edge of the jar with hemp and strips of linen placed above and close to the stopper, and hanging down to the rim.

Farther, that the iron wire may have force enough to keep down the stopper, I put a piece of cork seven or eight lines high, and sixteen or eighteen lines in diameter, in the middle of the large stopper which is itself too big to allow the wire to have any effect upon it. By means of this second cork, placed in the middle of the large stopper, I am able to make the wire take a proper hold of the cork and give due strength and solidity to the stopper.

When every thing has thus been foreseen and prepared, and, above all things, well corked, tied, and wrapped up in bags, there remains nothing to be done, but to apply the preserving principle, that is, heat, to the substances duly arranged, and this is the most easy part of the operation.

I place all the vessels, bottles or jars, upright in a boiler, which I then fill with cold water up to the necks of the vessels; I then cover the boiler with its lid, which is made to rest upon the vessels. I cover the upper part of the lid with a piece of wet linen, in order that the sides of the lid may exactly fit, and all evaporation from the water-bath be impeded as much as possible.

When the boiler has been thus filled and adjusted, I light the fire beneath. When the water-bath begins to boil, I take care to maintain the same degree of heat for the greater or less quantity of time required by the substances exposed to its influence. When this time has elapsed, I then instantly put out the fire by means of a coal extinguisher (étouffoir).

After the fire has been put out a quarter of an hour, I let out the water of the bath by means of the cock; after the water has been withdrawn half an hour, I uncover the boiler, and I do not take out the bottles till one or two hours after the uncovering; and this terminates the operation.

The next day, or a fortnight afterwards, for that is immaterial, I place my bottles on shelves, as I do wine, in a cool and shady place. If I purpose sending them a great distance, I think it worth while to pitch them before I place them on the shelves; otherwise this last operation is not absolutely necessary. I have now by me, bottles which have been three years lying under a stair-case, the substances contained in which retain as much flavour as if they were just prepared, and yet they were never pitched.

We have just seen, from all that has been said, that alimentary substances, in order to be preserved, should be, without exception, subjected to the application of heat in a water-bath; after being rigorously excluded from all contact with the air, in the manner, and with the precautions already indicated.

The preserving principle is, as I have already observed, invariable in its effects. Thus every loss I have sustained from any of the articles being spoiled, had no other cause than an erroneous application of the principle, or some negligence or omission in the preparatory process already pointed out. It sometimes happens to me even now, that my operations do not perfectly succeed; but no man makes experiments in any of the arts, or in any branch of natural philosophy, without being liable to disappointment. Nor can any one, therefore, who is employed in such a process as mine, flatter himself that he may not sometimes find his commodities spoiled from some defect in a vessel, or in the interior of a cork. But in fact, when due attention is given, these losses seldom take place.