This section is from the book "The Manufacture Of Liquors, Wines, And Cordials, Without The Aid Of Distillation", by Pierre Lacour. Also available from Amazon: Manufacture of Liquors, Wines, and Cordials, Without the Aid of Distillation.
This comprehends the preparation of the vessels for the production of vinegar.
Any vessel in the form of a barrel or cistern will answer for a generator. Thus tubs, kegs, whiskey or wine barrels, can be rendered available for this purpose. The operator will recollect that the more extended the surface is for the action of the fluid, the greater the benefit.
We will suppose the vessel to be packed is a wine pipe, of the capacity of one hundred and twenty gallons. It should be provided with a false bottom, composed of any kind of wood that will not yield a taste to the vinegar. This bottom should be secured about fifteen inches above the main bottom. The space thus formed is merely a reservoir for the vinegar, and its size should be controlled by the discharging capacities of the faucet, or stop cock.
This false bottom should be pierced with quarter-inch auger holes, allowing one hole to each square inch of the heading. The stop cock or faucet should be inserted about one inch above the main bottom; the false bottom is then to be covered with one layer of gunny bagging. This is to prevent any particles from filtering through the false bottom. About twelve inches above the false bottom, bore a one inch hole in every stave, following a horizontal line, that is, following the direction of one of the hoops round the barrel. In large generators, these holes should be four feet apart, lengthwise of the cistern. Thus a generator twenty feet high, would require five circles of these holes, each circle being four feet apart. It has just been stated that one hole should be inserted in every stave. This is not imperatively necessary; the holes are usually from four to eight inches apart.
The success of the whole process depends entirely upon the free circulation of the air throughout the generator. These holes allow a free passage for the air, which passes off at the top, in this manner: from four to eight canes of one or two inches in diameter, and from twelve to twenty inches in length: the joints should be removed from the inside, thus forming hollow tubes. These canes are intended to establish a current of air from the holes on the side, to these canes at the top of the generator. The canes project one inch above the false head, while the other extremity penetrates the contents of the generator.
Glass tubes are employed, instead of the canes just alluded to, but they are rarely found, and the cane ones will answer every purpose.
The next process consists in packing or charging the generators; and this consists in simply filling the generator to within four or six inches of the top, with beech chips and shavings. These two articles are to be of no peculiar shape; as they fall from the axe and plane, under ordinary circumstances, are the kind that are made use of. The chips and shavings should not be packed too solid or densely, as this would prevent the free circulation of the air; neither should the chips be packed too solid, in the vicinity of the holes in the sides of the generator.
The generator being filled as described, a head is to be fitted, and is to rest on the chips. This head is to be made in the same manner as the false bottom, viz. in having one hole to every square inch of the head. Each one of these holes is to have a piece of packthread, two or three inches in length, unravelled at one end, and with a knot tied on the other end. This knot prevents the packthread from slipping, or being forced through the holes, and the other end being unravelled, assists in a degree in minutely separating the particles that form the liquid that is to be acetified. The liquid by falling on this head spreads uniformly throughout the mass of chips.
The next step in the process consists in acetifying the chips, etc. This consists in passing pure vinegar through the generator, until every chip and shaving is perfectly saturated with vinegar. This object will be fully obtained by pouring and repouring the vinegar as fast as it runs through, some eight or ten times.
It is highly essential that the vinegar used in acetifying the chips, should be pure, or free, at least, from the mineral acids. The most common adulteration of sulphuric acid can be detected by saturating strips of glazed writing paper with the vinegar. If when the paper becomes dry and is of a purplish color, it will denote sulphuric acid. For the detection of the usual adulterations of vinegar, look under the proper head.
The last step in the process consists in preparing the liquid that is to be converted into vinegar. To forty gallons of rain water, add twelve gallons of proof whiskey, and one and a half pints of honey. This mixture is allowed to fall from a cock in the barrel that contains it on to the head of the generator, and by the aid of the holes in the head, this liquid becomes uniformly divided over and throughout the chips.
The particles of fluid becoming so minutely divided, is the cause of the rapid acetification.
This liquid escapes at the cock at the bottom of the generator. The liquid will have to be passed through the generator several times, before the aceti-fication will be complete, which will occupy from twenty-four to thirty-six hours. After the generator has been in use for a short time, the use of the honey maybe dispensed with in the alcoholic solution.
It would be difficult to explain why beech wood chips are required in the process. The chips of oak, ash, etc., have been used, but with indifferent success. Beech wood can be found in the form of " billets of wood," or plank, in every city of the Union. They need no other preparation but being cut to the ordinary size of common chips.
If the vinegar should pass from the generator not perfectly clear or transparent, this will be effected by placing a bed of white sand on the false bottom, to the depth of fifteen inches. This sand will of course have to be packed in before the chips are, in the following order: first, to prevent the sand from falling through the holes in the false bottom, cover it with a layer of gunny bagging, then lay on a bed of sand to the depth of five inches, then cover this with two layers of gunny bagging, and this with five inches of sand, and so on until the whole of the sand is laid in. The sand thus packed, will admit of a free passage for the vinegar.