How Slane whiskey is made
Slane is the first distillery Brown-Forman (of Jack Daniels fame) has built outside of the US, working with Conyngham family to create a purpose-designed production facility at Slane Castle in 2015. The whole process to turn Irish barley into Slane Irish Whiskey takes place in the part Capability Brown designed 18th-century castle stables which were restored as the distillery came to life.
From field to pot still - how Slane's barley becomes new make spirit
Inside the distillery, there are all wooden fermentation tanks, three hand-beaten copper pot stills and six-column stills. But before turning into liquid, some of the barley begins its life only a few hundred meters from the stables, grown on Slane's own estate.
Following in the tradition of Irish whiskies, Slane uses a mix of malted and unmalted barley. Common to other Irish whiskeys but very rare outside Ireland, the use of malted and unmalted barley stems from an ancient tax in the 1600s on malted barley. Ever cunning, Irish distillers learnt how to work around it, and in turn, discovered the benefits of using some unmalted barley in their mash.
Whilst delivering a sweet spice on the palate, unmalted barley also affects the texture of the whiskey, creating a richer and creamier mouthfeel as the liquid ages. Finding the perfect balance between malted and unmalted in a recipe is at the heart of every great Irish whiskey.
Much of the barley used is grown on the estate and benefits from the Conyngham family's focus on sustainability – more of which you can read on its own page – with crop rotation and reforestation across the farm's land. All other additional barley needed to produce the whiskey is sourced within Ireland.
Once Slane has its barley gathered, the process truly begins, starting with fermentation. Water comes from the ancient River Boyne, which runs alongside the distillery and through the heart of the estate. Again, sustainability measures were put in place from day one ensuring as little water as possible is used from the river and its native salmon population continue to make their way upstream uninterrupted. The final element to get things underway is of course yeast, and with that the fermentation process begins.
Slane ferments its wash in traditional wooden fermenters and allows this process to last long enough for complex flavours to develop – it's no rush or race to get this liquid into the stills and this patience is rewarded in the final whiskey.
The ferment, once finished, is triple distilled in both the purpose-built copper pot stills (partly designed by Alex Conyngham) and the column stills. This triple distillation is another hallmark of great Irish whiskies and creates a smooth character.
Ageing – Slane's three cask system
The distillate that runs off Slane's stills form the final distillation has a lot of its flavour and complex character there already, but if you tried it this would hardly be Slane Irish Whiskey. For that it must first be aged for a minimum of three years, and here is where Brown-Forman and the Conyngham decided to further build the profile of their whiskey.
Wanting to ensure Slane didn't only spend its time in ex-bourbon barrels, they opted for a three-barrel ageing system that made use of Brown-Forman's expertise in barrel making while also bringing in additional flavour. Firstly, they had new American oak barrels bespoke made for them in America with a specific level of heavy toasting and medium charring. Secondly, they also shipped over ex-Jack Daniel's barrels and lastly, slightly closer to home, they imported oloroso sherry-seasoned casks from Jerez in Spain.
This trademark three-barrel system gives the whiskey those traditional vanilla and charred oak notes alongside the more unique character of raisin and spice from the sherry and caramels, butterscotch and fruit from the ex-Tennessee whiskey. Blended by Slane's master blender, these flavours become the consistent taste that is Slane.