Just as juniper trees stay the test of time and can live to be hundreds of years old, juniper berries have been an enduring flavor in the repertoire of distillers through the centuries.
Liquids present challenges to archaeologists, as they leave only fleeting traces, so knowledge of ancient brewing practices is limited. One of the oldest known uses of juniper in fermented beverages was deduced from a remnant of Bronze Age brewing technology, a bronze strainer found in Southern Zealand, Denmark. Analysis of residues on it found traces of terpenes characteristic of juniper: fenchol, terpineol and junipene, indicating that juniper was one ingredient in the hybrid mixture of fermented berries and honey, which was a popular drink more than 3,000 years ago in Nordic countries. Out of the panopoly of beverage alcohols that use juniper as a flavor, Portuguese Aguardente de Zimbro, Polish piwo grzane (mulled beer) and Dutch and Belgian jenever are currently regaining popularity.
Jenever is the juniper-flavored spirit that spawned gin. Juniper was one of the flavorings added to jenever to render the distilled malt wine more palatable. In the 17th century, when William III ruled England, he taxed beer and cider to encourage imports of jenever from his Dutch homeland. In subsequent response to demand for juniper-flavored spirits, English distillers started making their own version of a predominantly juniper-flavored spirit called gin, which has become one of the major spirits in trade.
There are 67 recognized species of juniper, which have a wide variety of uses, from fence posts to medicines and incense. Common juniper (Juniperus communis) has dominated the beverage trade, as its berries are used for their flavor. For the plant’s purpose, the fleshy berries serve to encourage its spread by birds that eat the berries and subsequently deposit the seeds contained within the berries elsewhere. This has helped to make common juniper the conifer with the widest distribution across the world. It has numerous subspecies that are adapted to a variety of habitats—from sand dunes, limestone barrens and sphagnum bogs in North America, to Mediterranean mountains and rocky slopes in Scotland. In the early days of distilling with juniper, Scotland shipped juniper berries to the Netherlands. For many decades juniper from Tuscany was esteemed as the best juniper for gin. Recently juniper from the eastern Mediterranean has been gaining recognition, in particular juniper from Macedonia and Albania.
Provenance exerts a significant influence on the aroma profile of botanicals. The makers of Origin Gin have been exploring this by using only juniper from specific places as flavorings for separate batches. This provides the opportunity to compare the flavor of juniper in relation to terroir from rainy and cool Meppel in the Netherlands to warmer Arezzo in Italy. Science concurs with the perception that its growing region influences juniper flavor. Levels of the principal volatile components in juniper leaves and berries vary in relation to geographical factors such as altitude and latitude. This is because chemicals produced by plants in response to environmental factors—including those influenced by geography—are what we experience as flavor and aroma.
With more than 100 volatile compounds present in juniper berries, not only provenance but also processing method can change the flavor of the end product. The dominant volatile component of common juniper berries is α-pinene, which has the pine-woody aroma found in gin. Other volatile components present in smaller quantities that also have aromas described as woody are bornyl acetate, terpineols and β-myrcene. Juniper berries also contain other elements such as limonene, which adds a citrus aroma. Cold distillation of juniper retains a fresher and greener aroma than when juniper is distilled at higher temperatures. Juniper berries can be treated as a robust ingredient and macerated for a couple of days before distillation. Well-macerated juniper berries’ heavy tones can be balanced by other botanicals or by incorporating juniper that is more lightly treated by adding it to the still just before distillation or vapor distilling it in a basket within the still.
Much of the juniper used to make gin is wild juniper. However, some distilleries elect to grow their own. Roger Jorgensen grows juniper in South Africa to make his eponymous gin. Noting the pressures on juniper supplies from increasing demand, and the spread of fungus-like pathogen Phytophthora austrocedrae making juniper a more expensive ingredient, Jorgensen said growing his own juniper offers security for the future. He added, “Juniper is ideally suited to the Western Cape. We have that Mediterranean climate, great soils, it is a long-lived plant and also pretty to behold.” Roger also finds the flavor of his homegrown juniper preferable. “I get to pick fresh when I need berries, and the taste is very superior to the dried product traded on the world spice market. The dried berry is duller and tastes flat. I keep samples of the best grade dry berries imported from Italy and let visitors judge for themselves. Ours are always the preferred berry. They taste bright and citrusy.”
Even with so much variation in flavor possible with just one species of juniper, it is worth looking at other species of juniper as an ingredient. Some juniper species are known as too toxic for human consumption. Savine (Juniperus sabina) is considered poisonous because it contains high levels of sabinene, sabinyl acetate and sabinol. Redberry juniper (Juniperus pinchotii) and mountain cedar (Juniperus asheii) are known to cause gastrointestinal distress in grazing animals and therefore deemed unsuitable for human consumption.
There are 16 different species of juniper native or naturalized in the United States. Not all of these species are suitable for use in gin. Arizona juniper (Juniperus arizonica) is only found in Arizona and New Mexico, as well as in Sonora in Mexico. Collecting its berries is not a conservation concern, as it readily resprouts from trees cut down or stumps killed by fire and is even considered a pest plant in grasslands. Arizona juniper is not generally known as edible, though people do use its wood for fence posts. Western juniper (Juniperus occidentalis) grows in California, Nevada, Oregon and Washington, and is used in several gins, including Crater Lake Gin by Oregon-based Bendistillery. Potentially another 10 juniper species native to the United States could be used in distilled beverages, as they have a history of use as food plants and are abundant enough for collection of berries for commercial use to be sustainable.
For example, Eastern red cedar (Juniperus virginiana), the eastern counterpart of western juniper, can be found across the eastern states along the Atlantic coast from Maine to northern Florida and inland from the northern Great Plains to eastern Texas. Its timber is used to make red cedar oil. There are an assortment of references to Eastern red cedar berries as edible, spanning records of traditional plant uses by Native Americans to contemporary foragers trying local plants. At the Pine Mountain Settlement School in Kentucky, I saw a sample of Eastern red cedar berries in the edible plant collection of Ellwood J. Carr, a self-taught botanist who was interested not just in plant identification but also in their uses. One of the ways he learned about plant uses was exchanging goods from his store for local medicinal and edible plants. He acknowledged that a lot of these plants were used by European settlers and Native Americans. Eastern red cedar berries share characteristics with common juniper (Juniperus communis), but Eastern red cedar berries have an aroma and flavor that is mellower, as they lack some of the rougher tones of common juniper and are sweeter. Technically, both common juniper and Eastern red cedar berries contain chemicals that are considered toxic, although the plants are not necessarily poisonous. Like most edible plants, common juniper and Eastern red cedar fall on a continuum spanning food-medicine-drug-poison, depending on the quantity consumed. Much as common juniper has been found edible and within acceptable levels of toxicity, it is possible that Eastern red cedar is a candidate for gin and other distilled beverages which will add a flavor of seashore trees and soft lowland forests. In order to use Eastern red cedar or any other juniper species other than common juniper (Juniperus communis) in a gin, it is recommended that the distillate obtained from distilling alcohol with the berries be tested to ascertain which volatile organic components pass through the process, in what amounts, and whether any of them would present a concern for health.
Even only a brief exploration of juniper diversity reveals that a staple aromatic used in distilling has a much wider range of possibilities as an ingredient, all of which offer opportunities for distillers seeking to differentiate their juniper products from others not only through the way juniper is sourced and processed but also by incorporating local varieties of juniper.