Unlike other spirits, the flavor profile of gin is carefully selected before production. With whiskey, mezcal, rum, vodka and other commercially produced spirits, flavor compounds mostly result from a combination of effects relating to fermentation, distilling and aging processes. A gin maker, by contrast, chooses a flavor profile more directly, deciding on particular botanicals and herbs to achieve a vision. To be classified as a gin, only juniper is required. To please the consumer, a gin’s profile is layered and balanced with other botanicals, like a fine perfume.
A Scent Shaped by History
Juniper berries were first used in Holland to flavor spirit in the 1500s, when Dutch apothecaries experimented with herbs to disguise the unpleasant taste of their rye-based medicines. Juniper grew everywhere, and its strong taste and gentle bitterness successfully masked the burn of the rye distillate. Juniper was considered an effective medicine in its own right and a cure-all for digestive issues.
In 1689, with the ascension of Dutchman William of Orange to the throne of England, a transformation in local drinking habits and distilling practices took place. The laws were changed so that a prospective distiller only needed to post a sign informing the public of the presence of a still, and after 10 days they could begin distilling as much as desired. Juniper was useful for masking the flavor of the rough corn distillate. Thanks to this early distilling renaissance, juniper-flavored spirit became synonymous with the idea of Englishness. John Watney in his book on gin, Mother’s Ruin, remarked that “drunkenness was not considered a vice at this time in history. Indeed, the consumption of strong beer was one of the great British virtues.” Introduced in this cultural climate, gin was quickly accepted and soon surpassed beer as the new drink of the working class.
This new gin would hardly resemble the gin of today. It was cheap and easy to take the raw spirit produced by larger operations and then flavor and redistill it. Unlike beer, gin could be sold anywhere. But without regulation the product was often lethal. The juniper in cheap gin was substituted with turpentine, a substance derived from tree resin more appropriately used as a natural solvent, and which is toxic when ingested. Like juniper, turpentine contains alpha-pinene and has a forest-fresh scent, but it lacks juniper’s medicinal qualities. Even the high-quality gin of the day would be unrecognizable as modern gin. It was usually high in alcohol, sweetened, and would not contain the other botanicals that make up the modern gin medley. Dutch genever bears more of a resemblance to this early gin, with a simple juniper profile and the focus on the base spirit.
The evolution of the flavor of modern gin can be mapped to the history of class conflict in England. Protests, regressions, temperance movements, tariffs and fashion led to a change in the public perception of gin. Regulation had made gin expensive and unattainable for the masses. The cocktail bar was imported from America, and the cocktails served were usually gin-based. Gin was the drink of choice to mix with tonic in the colonies. From the 1870s onward, gin’s reputation had changed. Gin was respectable and attracted a new market. “The distillers began to produce unsweetened, dry gin which appealed to a more sophisticated palate,” writes John Watney about this period. This was the birth of the London Dry style. New botanicals beyond juniper were included in formulas. In a sense, regulatory policies failed to erase gin and instead squeezed it into a new form.
A scent shaped by biology
Today, with the explosion of craft distilling and the infinite variety of gins on the market, the identity of gin is changing once more. This time, the obscure has become the norm, with all diversity of roots, fruits, barks and flowers found alongside juniper. Often these botanicals are locally sourced, and have never been seen in gin recipes before, like seaweed or parsnip. However, it is worth noting that even with so much experimentation, certain core botanicals are conserved. In a survey of over 500 craft and multinational gins from the website The Gin is In [theginisin.com], five botanicals were found in nearly all gins. The prevalence of juniper, coriander, angelica root, lemon peel and orange peel in this new world of experimentation indicates how critical a contribution these botanicals make to the flavor that we perceive as gin today.
In biology, “flavor fingerprint” is the term used to describe a signature volatile blend produced in the plant at a particular developmental stage, like nectar from a flower in bloom or the scent of a ripe fruit. For hungry animals, a flavor fingerprint is a signal of an appropriate food choice or a danger that should be avoided. The five gin botanicals are combined to make a flavor fingerprint recognized as gin.
Juniper is an ancient coniferous plant, a member of the cypress family. Today, the common species Juniperus communis is one of the most highly distributed trees in the world. Many locations claim their own distinct variety. The little blue “berries” it produces are actually not fruit at all, but fleshy female seed cones. These pungent products of plant reproduction give gin its identity. The flavor of the berry is wonderfully complex and can vary from region to region. The piney, woody quality of the volatile compound alpha-pinene defines juniper and is always present in significant concentrations. Other such compounds include the musky, ripe and earthy myrcene; spicy, woody germacrene and floral terpineol.
Other botanicals complement the complex flavors found in juniper. Consider coriander, the seed of the cilantro plant. The aroma of the seeds is distinct from that of the familiar cilantro herb. The scent of the seeds is mostly composed of linalool, which has an intoxicating floral, fresh and citrusy flavor—think natural soaps and household cleaning items, or lavender. The second biggest component of coriander essential oil is alpha-pinene, the same compound present in juniper. Coriander complements and enforces the perception of juniper in gin, while adding something new. Coriander also contains significant amounts of terpinolene, which contributes to a citrusy, floral-fresh character. When tasting gin, the citrus components from citrus peel, notably limonene, can be detected up front, whereas the terpinolene from coriander carries a certain brightness at the finish and helps complete the experience.
Angelica is a relative of coriander, as well as fennel and carrot, and there is a family resemblance. The aroma profile of angelica root again contains a high percentage of alpha-pinene, which marries nicely with coriander and juniper. But angelica is important to the balance of gin as well as many herbal liqueurs and bitters, maybe for the reason that it contributes to the base notes of the flavor, as well as adding to its top notes. Angelica is savory and earthy, citrusy and sharp all at once. Chemically, the essential oil can contain, along with alpha-pinene, high quantities of citrusy limonene; woody, peppery sabinene; tangy, musky, and carroty cymene and minty, citrusy and herbal phellandrene. Angelica is thought of as a binding agent or fixative, but without much scientific evidence its binding and balancing effect on flavor remains anecdotal. (See “The Fixative Effect” by Aaron Knoll.)
Most imbibers can readily detect the scent of limonene, a major component in the essential oils found in orange and lemon peel. It is present in the other botanicals in lesser quantities; it especially shines in the orange peel. Linalool is found in larger concentrations in lemon peel, making lemon oil brighter and more floral. Other components include familiar terpinolene, alpha-pinene, myrcene, sabinene and compounds unique to citrus peels, like fruity octanal and hexanal, which smells like freshly cut grass.
Looking at the scent compounds that compose this volatile blend, these five core gin botanicals fit together as a whole and complement one another chemically. These five botanicals are associated through chemical composition even if we perceive them as smelling completely different. Their volatile compounds overlap in different proportions and together create a balanced, complex aroma.
A scent known to our ancestors
For millions of years, animals and plants have evolved side by side and have developed an intricate relationship mediated by the volatile compounds in scent. Plants cannot move and so produce chemicals to interact with the world. Animals have chemical receptors in the nose which send signals to the brain indicating scent and appropriate action.
Compounds like limonene, alpha-pinene and linalool did not evolve to affect processes inside the plant, but rather evolved to increase chances of survival through interaction with the environment. Gin has evolved in distillers’ hands toward a more appealing flavor fingerprint. It is no accident that these gin plants, with their long usage in human medicine, interact with our mammalian systems. These signals can in fact directly stimulate the brain to produce or regulate neurotransmitter levels or gene expression. Essentially, gin makers synthesize a man-made flavor fingerprint, or volatile blend, as a positive signal to consumers. The core components of gin have been selected over the years to maximize appeal, and the spirit has evolved to take advantage of our fondness for a good scent.
The flavor fingerprint of gin is familiar to someone who has experienced it before. The effect of distilled juniper, coriander, angelica root and citrus peel is generally pleasurable and attractive, but past experience and negative association can create a different perception. Gin’s flavor fingerprint involves a lot more than juniper. Beloved gin, shaped by history and biology, centuries of cultural and political reform, ideas about medicine, nationality and class, the span of human evolution — all embedded in your next dry Martini.