Originally, liqueurs consisted merely of the fermented juice of the grape, flavoured with various aromatic substances. The earliest liqueur 'on record is a mixture of wine, cinnamon, and honey, which was for a long period a very fashionable beverage, used on all occasions of festivity ; it is said to have been first prepared by Hippocrates. At a later period, other liqueurs were prepared by digesting in wine such herbs as hyssop, calamus root, and absinth, and were very popular in the tenth, eleventh, and twelfth centuries, under the generic name of " wine of herbs." The first liqueur which contained alcohol as its basis was simply brandy mixed with sugar ; it was more used as a medicine than as a beverage, and was known as "eau divine." The Italians were the first to employ alcohol to extract the flavouring and aromatic principles of plants and flowers, in order to produce agreeable and perfumed liqueurs. These were called " liquori," and were exported largely into other countries, and into France in particular. Shortly afterwards they wore manufactured and sold in Paris by Italian compounders on a larger scale. At the beginning of the last century, the Americans introduced their famous ratafla from cedrat, which they called crime des barbade4 ; and about the same time curagoa first made its appearance in Amsterdam, and anisette in Bordeaux. Since emu they have multiplied enormously, many of them being named after the inventor. Most are obtained by steeping in pure brandy or spirit different fruits or aromatic herbs, and submitting the resulting liquid to distillation. Cochineal, caramel, indigo, and other colouring matters are used to colour liqueurs, and they are also sweetened with sugar. Tho manufacture of these liqueurs constitutes tho trade of the " compounder " or " liquorist." Some liqueurs are prepared simply by steeping the ingredients in proof spirit for a length of time, without having recourse to distillation ; but these do not possess the Sue delicate flavour of the other class, and they are of small importance.
The first process in the manufacture is the solution in alcohol of the particular aromatic substances which are to supply the required flavour and aroma. The spirit employed for this purpose must be of the very best and purest quality. Rectified spirit of wine is, owing to its freedom from flavour, best adapted for the use of the liquorist. The ingredients are usually well bruised, and, in some cases, ground to powder. Immediately after this, they aro placed in the spirit, and the whole is constantly agitated for a longer or shorter period, as the case may demand ; generally, the time occupied is from five days to a fortnight. The distillation is carried on in any ordinary copper still, provided with a suitable condensing arrangement. Salt is sometimes added to the ingredients in the still. The products of distillation are brought to the requisite strength by the addition of pure soft water, or of the syrup used for sweetening. The sugar used must be of the finest quality, and is added in the form of a thin, clear syrup, after the spirit has been clarified or filtered, but never beforo. If great care has been bestowed upon the selection of the materials, and upon the subsequent operations, the liqueur, when made, will be perfectly clear and bright. Occasionally, however, they may appear clouded or milky; when this is the case, it is necessary to add a little white of egg, or of a solution of alum in water. These are termed "finings," and are generally effectual in removing cloudiness, and rendering the spirit clear and transparent.
Careful attention must be paid to the amount of flavouring matter added to the spirit. A very slight excess not only renders the liqueur disagreeably high-flavoured, but the excess of essential oil induces a milkiness also, which is extremely difficult to get rid of. It should be borne in mind that whenever the quantity required is uncertain, too little should be added at the outset, as the correct flavour may readily be imparted afterwards by the addition of a little more flavouring.
The process of distilling when applied to liqueurs must be very carefully attended to. The still should be thoroughly cleansed before each operation, and the coil well rinsed with hot water in order to remove the flavour left by the last distillation. When conducted over a naked fire, the still must be placed on an iron grating which rests on the furnace, to prevent the ingredients from adhering to the bottom of the still and becoming burnt, thereby imparting an ompyrcumatic flavour to the products. The boiler of the still should be only about two-thirds full, and the plants employed, especially if they be dried, should be cut up as small as possible, in order to prevent them from swelliug. All joints should be carefully closed with a paste made of flour and water, over which is placed a strong band of paper or linen, so as to cover the joint completely and closely. Heat is then applied, at first gradually, and afterwards increased as the operation proceeds; on the appearance of the first few drops, it is well to moderate the heat slightly for a few moments. Great care is requisite in the management of the fire in order to produce a regular and even flow of liquid from the coil ; if the fire be pushed too rapidly, the fsiuts will come over and an empyreumatic flavour will thereby be produced in the spirit ; which flavour is highly objectionable. The water in the cooler must be changed frequently.
Distillation over an open fire, although it progresses with more rapidity, has the disadvantage of altering the product more or less, owing to the unequal distribution of the heat. Distillation over a water-bath is conducted in precisely the same way, but it does not require so much atten tion. The boiler is placed on the furnace—the grating previously used being removed— and is half filled with water. The water-bath containing the various ingredients is then fixed in its place, the joists are carefully luted, and heat is applied. The products obtained by this method are much purer, and possess a far more delicate flavour, owing to their perfect freedom from empyreuma, than the products of distillation over an open fire. But perhaps the best method in use is that of distillation by steam, which is conducted in the following way the steam boiler three-fourths full of water, and boil. When the correct pressure is indicated by the steam-gauge, admit a small jet of steam to the still so as to heat the contents at first gently; the cock may afterwards be opened to the full extent. The still is managed precisely as in the previous operations. This method is employed only in the large liqueur manufactories owing to the expense of erecting boilers, &c., hut, when once established, the process is preferable to any other for economy of fuel, facility of working, and quality of the product. The following is a list of plants which should always be distilled by steam :— Absinth. Fennel. Mclilot. Rose.