The dose varies according to the degree of the aroma, from 2 to 10 centilitres per hectolitre (⅛ to ⅚ of a gill, or 5.4 to 27 fluidrams to 26.4 gals.)
Gillyflower, or Stockgilly.—The essential oil of this flower may be extracted by pressure, by maceration, or by distillation, and is found in commerce. To make the bouquet, the oil is used, or the concentrated essence, which is produced by the distillation of the bruised flowers with alcohol of 85 per cent., in the proportion of 300 grammes of the flowers to 5 litres of alcohol (10½ oz. to 5¼ quarts). In the absence of an alembic, the aroma may be extracted by infusion, as in the case of iris, by macerating 100 grammes of the bruised flowers to 1 litre of alcohol of 85 per cent. (3½ oz. to a quart) for eight days, and filtering. Gillyflower is rarely used alone; but by adding a very small quantity of it to iris, a good effect is produced, and the perfume becomes more intimately mixed with the wine, for the oil of gillyflower is heavier than water; but this aroma should never predominate, and is best for old wines without bouquet.
Vine Flowers are gathered and the petals infused in alcohol of 85 per cent., in the proportion of 100 grammes of flowers to 5 litres of alcohol (3½ oz. to 5¼ quarts). After macerating for eight days, it is distilled in a water bath. This aroma, which is very volatile, is used in the dose of 5 centilitres to a hectolitre (13.5 fluidrams to 26.4 gals.)
Mignonette.—The perfume of the mignonette, like that of many other flowers, is obtained by picking the flowers from their stems, bruising them, and placing them upon layers of cotton or pieces of linen impregnated with fresh oil, or other sweet fats; oil of ben is preferred. The flowers are renewed every four hours, till the cotton or the cloth is charged with perfume. The oil or fat is removed by pressure or otherwise, and the essential oil is dissolved out with alcohol of 85 per cent., which is afterwards separated from the fixed oil, and filtered. The extract of mignonette so obtained is employed in the proportion of 1 to 5 centilitres to a hectolitre (2.7 to 13.5 fluidrams to 26.4 gals.) but oftener it is mixed with other perfumes.
Nutmeg is employed in the form of spirit distilled from the nuts over the fire, 500 grammes of nuts to 10 litres of alcohol (1 lb. to 10½ quarts), or in the form of a tincture made with the same proportions of nuts and alcohol, or a small quantity of the essential oil is mixed with other aromatic substances. This preparation, particularly the tincture or the distilled spirit, has a good effect. Being heavier than water, it assists the mixture.
Bitter Almonds and Fruit Pits.—Their oil is found in commerce, and its aroma is due to the hydrocyanic (prussic) acid contained in it, which is poisonous, and therefore the oil should be employed in the smallest doses.
Sassafras.—The essential oil is extracted from the wood and bark by distillation, and can be purchased in the market. It is heavier than wine, and fixes the lighter perfumes. It is used only secondarily, and in very small quantities.
Other Aromas have been tried, but they can only be used as auxiliary to the three first named, iris, gillyflower, and strawberry, because their odors differ essentially from the natural bouquet of mellow wines.
Effects.—These preparations give wines a bouquet or aroma which partakes of the substances employed, but they do not give the distinctive flavor (séve) which characterizes fine wines, and the result only flatters the sense of smell. These perfumes are very volatile, and it does not require a very delicate or a much experienced palate to distinguish them from the natural bouquet of wine, and persons of delicate sensibilities are disturbed by them, if too pronounced.
When a wine has been artificially perfumed, it still preserves its taste and earthy flavor; it has simply changed its odor. Taste it without smelling, and its distinctive flavor will be recognized. Mr. Boireau says that, notwithstanding the contrary announcements of interested manufacturers, they are not preserved like the natural bouquets and flavors, but, little by little, they become enfeebled, and are volatilized with time.