botanical is the generic term used to describe the plants or their parts (including fruits, leaves, flowers, roots, seeds, and barks) or other organic substances that are used to flavor spirits. Historically, botanicals were used for their curative properties, as well as to act as adjunct flavorings to improve the taste of medicinal distillates. Medieval monasteries cultivated extensive gardens of medicinal plants, and monks drew heavily on them in making early European spirits. See
Botanicals contain complex, volatile organic chemical compounds in the form of concentrated hydrophobic liquids, or “essential oils,” as they are known. Essential oils are stored in the oil cells, glands, or vessels of the plant, where they act as powerful attractors of insects, to ensure pollination, or as chemical defenses to stop the plant being eaten by a predator, or as warning signals to other plants that there is a predator about. These essential oils also contain the plant’s aromas and flavors.
Growing regions and the climate and soil conditions that come with them play a large part in the sensory profile of an essential oil. Since photosynthesis is responsible for the formation of the hydrocarbons that make up the oils, a change in hours or intensity of sunlight can create a change in the balance of their component compounds. The soil the plant grows in yields the other elements that go into the oils, such as sulfur and nitrogen. A change in terroir can make the same botanical—juniper berries, for example—much more or much less aromatic.
Essential oils are commonly extracted via steam distillation, cold pressing, and solvent extraction or maceration, where they are steeped in high-proof alcohol. Essential oils are not normally miscible in water; the ethanol acts as the solvent and hence carrier of flavor. Generally, spirit producers use steam distillation, cold or hot steeping (macerating), or a combination thereof, to extract the essential oils and chemically attach them to ethanol to form a flavored spirit. However, any spirit that comes into contact with a natural substance uses organic chemical compounds to some degree, whether that be the pinene flavors from juniper berries or vanillin flavors produced by oak casks.
See also gin; phenols; and terpenes.
Williams, David G. Chemistry of essential oils, 2nd ed. Weymouth, UK: Micelle, 2008.
By: Sean Harrison