To truly appreciate gin, understanding juniper is key.
Its role is as integral to gin as casks are to whisky, grapes to wine, and the dilution of ice to bartending. You can’t have gin without juniper berries.
By law, juniper not only has to be included in gin but it should also be the predominant flavour. Rightly so – the very name ‘Gin’ stems from ‘genièvre’ in French or ‘jenever’ in Dutch, both signifying juniper.
Here’s everything you need to know, from juniper trees, berries and beyond…
The botany of juniper
Juniper trees, of which there are almost 70 species depending on the taxonomy, are typically low-maintenance, evergreen plants of varying sizes and shapes. These hardy shrubs, which thrive in many Northern Hemisphere countries, do particularly well in soils with acidic pH, but can also tolerate less acidic conditions.
Common juniper trees possesses one of the most extensive geographic ranges of any woody plant. Its habitat stretches from Western Alaska, throughout Canada and the Northern USA, to the coastal regions of Greenland, Iceland, Europe, Northern Asia, and Japan. It even has a presence in North Africa and India. It’s everywhere!
Elevation doesn’t deter juniper either; it’s been found at heights of up to 3,500 metres.
Interestingly, juniper trees are dioecious, meaning there are distinct male and female plants. Male flowers release pollen in the spring, which is dispersed by the wind. Female flowers eventually grow into berry-like cones, ripening from green to a dark, blue-purple colour over 18 months.
Despite all juniper species growing berries, most are considered too bitter to eat. Try one and you’ll see why! Juniperus Communis is the variety specified by EU Law as being legally required in gin production. (see more on Gin Rules here). Other countries / regions do not specify the variety, simply using the word juniper – a fact that producers are leveraging to fantastic effect.
Juniper seeds usually require two winters of dormancy before sprouting. Thereafter, it’s slow-growing as a species, but in optimal conditions, it can grow 25-30cms a year.
Terroir and alternative species
As you would expect from a plant that grows in so many places, the concept of ‘terroir’ can be applied to juniper. The soil, climate, and conditions in which a juniper tree grows influences the taste of gin.
Macedonian crops are different to Italian, which is different to Croatian and so on.
Gin distillers are very particular as to which they select, and how they maintain year on year consistency. They work closely with professional botanical suppliers for a reliable, high-quality supply.
While it would be nice to think that a self generated supply might be possible, in most parts of the world juniper bushes have faced a dramatic decline due to pastoral farming and overgrazing, rendering self-sustaining populations difficult to maintain.
Argentinian producers in Patagonia are a notable exception to this, so too are some of the smaller producers in Scandinavia. That said, most will state that once their scale reaches a certain point, it will no longer be plausible to sustainably source 100% locally.
Beyond Communis
Some producers don’t stop at just using Juniperus communis either. Certain U.S. distilleries have started experimenting with ‘New World’ juniper species like Juniperus occidentalis. The same goes for producers based in Formentera, Palma, India and Australia.
There have been American gins that use the variant is Juniperus Deppeana, or Alligator Juniper. The variety got it’s name because its dark grey-brown bark, unusually hard and cracked into small square patterns, resembles an alligator’s skin. Meanwhile, and perhaps most well-known is the African Gin, Procera, that uses its namesake variety.
Each of these varieties add a different element to the flavour profile and showcase just how wide-ranging juniper can be.
Most of these commercial gin bottlings use local varieties in conjunction to communis as to not flout the EU rules or challenge the drinkers expectations too far. However, with the rise of gin in Asia and Mexico, expect this to evolve over the years ahead.
Flavour aside, more often than not, producers also use alternative varieties in small doses due to the fact that they are locally foraged (limited availability). It’s not just that they only want to add an extra dimension, not replace communis altogether – it’s also because they simply aren’t able to do it consistently.
What flavours does juniper give gin?
Even though it’s only one botanical, juniper berries give off an array of flavour.
The predominant one is piney, forest like notes stemming from the hydrocarbon Alpha-pinene, which makes up between 40 and 45% of the aroma molecules in juniper.
The second most prevalent molecule is another hydrocarbon called Sabinene (around 5-15%). Additional molecules include Lemonene (4-5%), Farnesene, contributing a floral note (around 5%), and Borneol, with its woody notes (around 5%), to name a few.
While drinkers never need to know what compounds make up flavour profiles, it’s interesting to delve into. It shows just how many different elements combine together and why distillers are so specific about their source. Each molecule introduces unique aromas and flavours that, depending on their overall percentages, combine to produce slight variations in the final profile.
Where it grows and the conditions it is in changes the percentages of everything…
New frontiers for juniper in gin
Despite the growing use of alternate juniper species and co-inclusions of them, the majority of the innovation is around how its processed and distilled.
Exemplifying the full spectrum of juniper, Hepple Gin uses junipers from three different regions: Macedonia, Italy, and the Hepple Estate. Each adds a unique twist to the gin, creating a cocktail of juniper berry nuances.
More interestingly, Hepple also showcases innovative production methods in how it extracts flavour. Some is distilled in a traditional pot method. Other juniper is distilled through modern a vacuum distillation. Lastly, they use supercritical extraction to process some of the juniper. Three different techniques applied to three different sources.
They remain on the extreme edge of what producers do, but they show the two factors at play. The source of the juniper berries and the way they are processed are both as important as each other.
Other distillers doing equally ambitious and progressive distilling techniques are Oxley and Conte De Grasse.
Smoked Gin?
Another growing field of experimentation is imbuing smoke into juniper, which then get’s transferred over during distillation.
An example is Fisher’s Smoked Gin, that suspends the botanicals in a traditional Smokehouse. This infuses the smoke into the juniper prior to maceration. Meanwhile, Citadelle’s Saison de Witch is a gin crafted using juniper that had been smoked on fire pit. In a similar use of fire, the Limited edition Tarquin’s Gins Tan Ha Mor and Treth Ha Mog, employed a similar method using a beach barbeque to imbue smoke and char into the juniper.
Beyond using juniper berries, distillers are also exploring the usage of juniper wood for ageing gin. It was a practice pioneered by Blackwater Distillery in Ireland and perfected by Jon Hillgren of Hernö in Sweden.
While juniper wood casks pose a challenge due to their porous nature (and that many juniper trees are small in their nature), the results are truly exceptional. Gins aged in juniper casks have a resinous depth and unique sappy character – delicious on many levels.
Juniper is the soul of Gin
In conclusion, juniper is not just a mandatory ingredient in gin; it is its soul. From the varied species and the concept of terroir influencing flavour profiles, to innovative processing methods and the exploration of new frontiers, juniper remains central to gin’s identity and evolution.
Its versatility and complexity underscore the spirit’s uniqueness, demonstrating why gin continues to captivate connoisseurs and casual drinkers alike.
As we have seen, the world of gin is as rich and diverse as the juniper itself, a testament to the ingenuity and passion of distillers worldwide in their pursuit of perfection.
