Return of the native

Return of the native

Irish Distillers are helping to revive the country’s oak trees

Whisky Learning | 27 Mar 2020 | Issue 166 | By Rob Allanson

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When you come to think about it, the spirit we all love, whisky or whiskey, whatever your spelling preference, has to be up there with some of the ultimate slow foods we have. And I mean the blends too.

Take a couple of minutes to ponder this: peat takes a seriously long time to be created, the barley takes at least a year to get from ground to the mashtun, then maturation can be anything from a year upwards. Of course, you also have to take the oak into account.

Trees are darned magnificent things. I struggle to think of a world without some form of tree-like being. Where would New England be without its fall colours? Would Robin Hood be the same if he lived in the middle of a city? Also, where would we all be without the green lung of the rainforest? From a tiny seed grow these giants in all shapes, sizes and colours, and for us whisky lovers it is the mighty oak in its various guises that provides most of the magic for our chosen tipple.

I often say when doing tastings that casks are like children: they don’t do what you expect most of the time. In fact, you can put two together in a warehouse that were filled on the same day and end up with two different whiskies. Now I know that a lot of that can be explained by science, but Mother Nature still has her hand, and influence, in there too.

Usually, when we are talking about oak it’s either from the US or Europe, generally Spain or France, so when the chance to try something with native oak comes along, jump at the chance. There’s a lot of playing about with oak varieties (see Becky Paskin’s piece on Chinquapin oak in this edition), and even experiments where the distiller has effectivetly picked a tree to turn into a cask. That’s where we are with the latest release from Midleton Very Rare Knockrath Forest, the third release in the Dair Ghaelach collection.

A lot can be explained by science, but Mother Nature still has her hand, and influence, in there too


The project first emerged back in 2015, with the launch of Midleton Dair Ghaelach – the culmination of some 10 years of work by Irish Distillers’ Midleton Masters. Ever keen to innovate and create unique and exemplary whiskeys, the team decided to explore the possibility of maturing Irish whiskey in native oak. Led by master of maturation Kevin O’Gorman, master cooper Ger Buckley and master blender Billy Leighton, the company set out to source sustainable Irish oak from estates throughout Ireland to produce a series of whiskeys, each with their own individual history and taste profile, that could be traced back to the specific tree from which the oak cask was made.

The theory is that, similar to Scotland, there must have been some reliance on casks made of native oak at one time, but logging and mass deforestation of the island country ended that long ago. This heavy logging turned Ireland into one of the most deforested countries in Europe. By the 1970s, forest cover was down to just four per cent of the entire island’s territory.

The lack of trees forced a variety of industries, including an Irish whiskey industry that dominated the world trade of the liquid in the 19th century, to import timber in order to meet its constant needs. Until now. The last time Irish oak was a staple of Irish whiskey was at least a century ago and the distillery’s records reveal the purchase of new Irish oak as far back as the 1820s, but nothing more recently.

“Until we started this project, Irish oak had not been used to mature whiskey for well over 100 years,” says Kevin O’Gorman, Midleton’s master of maturation. “Today, thanks to sustainable practices, we can harvest small volumes and trace each bottle right back to the very oak tree that helped create it.”

This gives the whisky an interesting tag, that it is truly Irish: including Irish barley, Irish oak and Irish water. This will appeal to those of a collecting mindset and, if you can still get your hands on the previous editions, one should start with 2015’s Grinsell’s Wood edition. This was the first expression in the collection and matured in barrels made with Irish oak grown on the Ballaghtobin Estate in County Kilkenny. The second edition appeared in 2017, Bluebell Forest, created using oak from the Castle Blunden Estate in County Kilkenny. For this third edition, the Midleton team headed to County Wicklow and selected the Knockrath Estate in the ancient Vale of Clara, where oak has grown for more than 150 years, set against an idyllic landscape of mountains and lakes.
The story goes that members of the Brabazon family have been the stewards of Knockrath Forest since the 16th century and they continue to sustainably manage the trees from one season to the next. As a quick aside: under their guardianship, the Knockrath Estate became one of the first sites where the iconic Great Spotted Woodpecker set up residence on its return to Ireland following years in exile.

Known for its cool summers and heavy rainfall, the climate of County Wicklow impacts the density and porosity of the oak. This, in addition to a lighter toasting of the wood and combination of distillates, results in some very subtle flavour differences between Dair Ghaelach Knockrath Forest and its predecessors, Grinsell’s Wood and Bluebell Forest editions.

Once felled, the carefully harvested trees were shipped from the estate to the Maderbar sawmills in Baralla, Northwest Spain, where they were traditionally quarter-sawn into staves for barrel manufacturing and transferred to the Antonio Páez Lobato cooperage in Jerez. After a 15-month drying process, the staves were worked into barrels and given a light toasting before returning to Ireland.

Back at Midleton Distillery, the virgin oak casks were filled with Irish pot still whiskeys ranging in age from 13 to 26 years and left to do their stuff. Following two further years maturing in the Irish oak, the casks were regularly checked until the team felt the whiskey had the perfect balance of flavour, aroma and wood contribution, and ready for bottling.

Compared to other regional oaks, Irish oak is less dense and therefore happens to be more open in its structure. The wood also holds greater levels of some lignin derivative compounds, such as vanillin and vanillic acid, and more furfural than other oaks, magnified by the fact IDL used it as virgin oak – all those flavours are packed in there waiting to be released.

Billy Leighton adds that using native oak has fostered an awareness and appreciation among whiskey lovers that there is even a subtle difference between trees which contributes to a whiskey’s flavour. “This is truly a taste of Ireland in a glass; the barley, water, oak and, indeed, craftspeople at the heart of this expression are all home-grown, making us extremely proud to share this latest expression,” he continues.

So what can we expect from the current harvest of special trees? There are seven individual oaks that make up the current collection and, overall, I would say that if you are expecting serious wood domination here, think again. While there is a definite strong oak note to the whiskeys, there are subtle differences to each tree. Yes, you have that wonderfully spicy, oily pot still backbone that you would expect from Midleton, but that careful aging gives each whiskey a different shade to it.

Delving into the collection makes you wonder what might be coming next; each time you think Irish Distillers has reached a certain peak, it defies your expectations again. Tasting this new whiskey makes me curious about what else is going on in Cork, and also in other distilleries where similar experiments are taking place; one thinks specifically of Buffalo Trace and Woodford Reserve in the US, Glenmorangie in Scotland and a batch of other distilleries that are known to tinker with wood.

Midleton Very Rare Knockrath Forest Tree by tree



1. Straight off the top this is super complex stuff. A mix of linseed oil, toasted oak and warm brown sugar. It is well balanced, with some exotic fruit notes coming through, mandarin, guava and lychee. Pears poached in cider too.

2. Initially this is super sweet, golden syrup. It also seems a little shy until you add a drop of water. It’s like the clouds part and all the sweetness has been waiting to be released. Toasted marshmallows with melting dark chocolate, brown sugar syrup, roasted and candied hazelnuts.

3. More potstill character to this one coming through with seriously dense, fig and date like notes abound. There’s a real oily, almost malt extract and fatty quality, if there was smoke you would say bacon rind. Stewed prunes and dark treacle toffee sweets, sticky and moreish.

4. A really mixed spice bag with this one, peppery, a little chilli kick and then the sweet fatness of bbq prawns in their shells. Then waves of sweetness, tinged with a bitter edge, marmalade without orange rinds. There’s also plenty of orchard fruits lurking here too. Be gentle with any water as it seems to back down the intensity and the vibrancy.

5. Like walking into a florist’s shop eating candyfloss, it’s all heady floral notes and spun sugar sweetness. Packets of pistachio-laden Turkish delight, sweet and nutty. A little water pumps up the sweetness but also a nutty, woody quality too.

6. A huge and complex character here. A wood-panelled room after the polishing team have finished work. Oily, with beeswax wrappers and church incense. This slowly gives into chocolate walnut whips and just on-the-turn oranges.

7. Really reminds me of waxed paper packets of Pontefract cakes with a little salt edge. Then it moves to salt caramel ice cream. Finishes with a serious herbal apothecary note.

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