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.
Straw is frequently used in the sand, to admit of free passage of the fluid. The decomposition of the straw soon sets in, thereby imparting an unpleasant taste to the vinegar.
And in some instances, shells are mixed with the sand, which prevents it from becoming too densely embedded, which better enables the fluid to filter through it.
Persons preparing to engage in this business, can have a series of generators, one arranged above the other. A two or three story house will be necessary for this. The generators may be made of 120 gallon wine pipes, one resting on the other, and the barrels on each floor can be connected with each other by the aid of pipes; and after the chips have become thoroughly saturated with vinegar, the generators will only be required to be fed with the whiskey or alcoholic solution, which will be converted into vinegar on its first passage through the chips, though it may be necessary to pass the liquid through the generator until it does become sufficiently acetified.
Sulphuric acid is the most economical acid for adulterating vinegar, being from two and a half to three and a half cents per pound. The quantity of this acid to be added, will have to be governed by the palate. Sulphuric acid, diluted to the strength of common vinegar, leaves in the mouth a metallic, salty taste. This taste is removed by forming a weak solution of sulphuric acid and water, then reducing it to the strength of good vinegar by the addition of pure vinegar.
Analysis will prove that all of the different varieties of vinegar offered at the public auctions, are nothing more than dilute solutions of sulphuric acid; the fine acetic odor and taste being the result of the addition of a small portion of acetic acid or pure vinegar, such as that formed by the generators just described.
The operator will recollect that these "generators" possess no decolorizing properties, and hence, vinegar intended for white wine vinegar, should be made of colorless whiskey. That which is made from colored whiskey, is sold under the names of crab-apple vinegar, clarified cider vinegar, malt vinegar, etc., etc.
Vinegar containing excessive quantities of sulphuric acid, will sometimes leave a metallic taste, which can be corrected by adding a small quantity of the infusion of grains of paradise and pellitory. This metallic taste just alluded to, is sometimes perceptible upon the addition of minute quantities of sulphuric acid, and the taste is difficult of concealment. This is an evidence of impurities in the acid, and accordingly it should be rejected.
The infusions of pellitory and grains of paradise, are made by adding four ounces of bruised pellitory and one pound of the grains, ground to a powder, to three gallons of whiskey, and infusing for four days and then strain. This is used for giving a body to and for removing unpleasant tastes from vinegar. The manner in which this infusion should be used, will be left entirely to the judgment of the palate. This vinegar may be sufficiently " sharp," and be deficient in body; or a peculiar taste may exist from sulphuric acid. These objections will be removed upon the addition of a glassful of the infusion just mentioned, to every forty gallons of the vinegar.
The clear, or white wine vinegar, should always be sent into market in neat wine or brandy casks, of any kind; each head should be freshly plastered with plaster of Paris. This consists of mixing the plaster of Paris with water to the consistency of common mortar, and applying it to the heads of the barrels immediately.
Vinegar is colored with the same materials that liquors are. Colored vinegar has never acquired any celebrity, and is not much sought after by consumers. The operator will find the most remunerative investment in the manufacture of white wine vinegar. The generators having the sand filtering attachments, as described, will be enabled to produce an article of a fine color. Instances often arise that the water made use of, is rain water that has flowed from shingle roofs, and is of a dirty, yellowish color. Usually, this color disappears after being passed through the generator the second or third time, but when this fails to remove the color, it is usual to cover the false bottom of the generator to the depth of five inches, with rice, and then packing on this the usual quantities of sand, as before described. The liquid that has been filtered through rice, is beautifully transparent, but when the rice filtration is not practicable or cannot be made available without difficulty, this objectionable color in the vinegar will have to be concealed by coloring it with burned sugar, same as for cider vinegar. The novice will recollect to add the coloring in minute quantities, otherwise the vinegar might become too highly colored.
What has been said about adulterating vinegar, only applies to the cheap vinegar. Pure viuegar can be manufactured by the use of the generators, at such an astonishing low price, that adulteration would appear useless.
Colored and flavored vinegars have but recently appeared in commerce. They are usually made of sulphuric acid diluted with water, and colored to suit the fancy. The aromatizing articles consist of the oils of wintergreen, lemon, orange, almonds, vanilla, ambergris, oil of roses, etc., etc. Perfumed vinegars are generally colored, and are usually found in five to ten gallon kegs.
Adulterations of Vinegar. - The principal foreign substances which vinegar is liable to contain are sulphuric and sulphurous acids, certain acrid substances, copper and lead derived from improper vessels used in its manufacture; muriatic and nitric acids are but rarely present. Chloride of calcium will detect free sulphuric acid when boiled with the vinegar, without causing the least precipitate with the minute quantity of sulphates always present in the liquid. Chloride of barium is not a suitable test here, as it will cause a precipitate with these sulphates, when no free sulphuric acid is present. Sulphurous acids may be detected and estimated by first precipitating the sulphates and free sulphuric acid, by baryta water, next acting on the vinegar with arsenic acid, which converts sulphurous acid into sulphuric acid; and, finally, precipitating the newly-formed sulphuric acid by chloride of barium from the sulphuric acid in the last precipitate. Its equivalent of sulphurous acid is easily calculated. Muriatic acid may be discovered by adding to a distilled portion of the suspected vinegar a solution of nitrate of silver which will throw down a curdy white precipitate, if nitric acid be present - an improbable impurity. It may be detected by its producing a yellow color when boiled with indigo. The acrid substances usually introduced into vinegar are red pepper, long pepper, Guinea pepper, pelli-tory, and mustard. These may be detected by evaporating the vinegar to an extract, which will have an acrid, biting taste, if any one of these substances should be present.