Whiskey. What’s Wood Got To Do With It?

Whiskey.

What’s Wood Got To Do With It?

Cooper Ger Buckley with a stave secure in his "horse"

“You can take whiskey out of wood but you can never take the wood out of whiskey.” This was a quote in the sales literature when, a year or two back, Irish Distillers launched their Cooper’s Croze (one of a trio that also included the Distiller’s Safe and the Blender’s Dog).The influence of oak can be seen in the Croze through it’s vanilla sweetness, rich fruit flavours, floral and spice notes.  

Last week I had the privilege of seeing Ger Buckley, the master working cooper at Irish Distillers HQ in Midleton, in action, a bottle of the Croze he produced in the background and a croze in his hands. A croze? Ger has used a croze all his working life. He uses it to cut the grove along the top of the staves to hold the head (the circular cover) in place.

It is an old and simple tool, just like his other key implements, the hammer and the driver (both heavy), the carving axe (bevelled on just one side) and the adze (a shaping axe). The hammer, the axe and the adze are ancient tools, sacred tools in some cultures around the world.

Ger with croze in hand

Remember, there is no measuring in the cooperage, all done by eye, but each barrel or cask has a related compass. Other tools include the dog (used to insert the reed that makes a seal between upright and horizontal) and the horse and a stationery plane.

Our opening sentence indicates the importance of wood in the whiskey making process. Ger will say that it accounts for more than fifty per cent of the input to the final bottle and many distillers will agree with him.

Ger, a 5th generation cooper, had (up to a month ago) only ever used white oak. Very recently though, in Irish Distillers’ new innovative series Method and Madness, one of the whiskeys was finished in a Sweet Chestnut Cask.

The three basic tools: adze, hammer,  and axe

Both the American bourbon barrels and the Spanish Sherry butts are made from white oak but each performs very differently. Vanilla and caramel are among the flavours that the American version contributes while dark fruits (such as plum) and sherry flavours come from the European cask.

Recently, for the Midleton Dair Ghaelach whiskey, Irish oak, from ten trees, was used. The cooper told us that it is very sweet (there is sugar in oak!), chocolate too and vanilla, closer to the US than Spain. 

“Did you know that we once supplied staves to Spain?” said Ger. “Up to the 17th century, Ireland was covered in oak forests… the English, who took a lot for their naval forces, are often blamed for the decline..but we ourselves didn’t renew.”   

Ger collapses cask and re-assembles it, all in a few minutes, talking all the time!

Oak coverage here “is on the up again”. And the hope is to get it up to about 17% which is the European normal. “Not just oak though,” warned Ger. “We need bio diversity.”

And this diversity within the forest is good not just for the wood and its creatures but also for the distilleries, and anyone else who needs good timber. “We are looking for a large beam of oak.” And that is achieved by planting other species, beech for instance, close to the oak which then is forced to expand straight up and grow as a beam!

Oak for the cooperage is the most expensive. There must be no defects. The method of sawing, called quarter sawing, also leads to waste but it doubles the strength of the wood.

Ciaran O’Donovan makes a point about oak in the Whiskey Academy.

Good and all as the oak is, it is not perfect. Leaks do arise and most of these can be repaired quickly and without too much loss. But no one had yet found a solution to evaporation. It is about 2% in Ireland, about 30,000 bottles of Jameson a day! That is not too bad, compared to hot climates. In Tennessee it can reach 7%. All around the world, whether the distillery is producing brandy, whiskey or rum, the angels get their share!

Ciaran O’Donovan. of the Irish Whiskey Academy, who led our group in the 2-day immersion in all things whiskey, also filled us in on the importance of the wood (of oak in particular) saying 60% of the flavour comes from it. Did you know that Irish Distillers bring in about 140,000 barrels (with their internal surfaces charred) from America each year, swamping the few thousand Sherry butts (toasted internal surfaces) that come from Spain each November.

Just one corner of one warehouse

By the way, these butts belong to IDL from the very start. They buy them in the north of Spain; they are then taken down to the south, to Jerez and filled with sherry; after a few years they arrive in Midleton. Interestingly, when they come they will have up to five litres of sherry inside! Ciaran called the sherry barrel a "work of art" compared to the bourbon equivalent which, by comparison, has a lot of mechanisation in its production.

The butts (500l) add colour and tannin and flavours of dried fruit, nut, fig, even Christmas cake. The once-used bourbon barrels (200l) are empty! They have been especially sourced by three companies in the US and must be top class. Key flavours here are toasted wood, sweetness and vanilla.

IDL also source casks from other countries: Port pipes from Portugal, drums from Madeira, casks from Malaga (Green Spot 12 yo), casks from Marsala in Sicily, and wine barriques from Bordeaux (Green Spot Leoville Barton).

This comes with a disc of oak in the gift box

And the Irish oak? Well, we did get a chance to taste the Midleton Dair Ghaelach, matured in Bourbon casks and finished in Irish oak, a “project at its beginning”. It has a lovely nose, unique colours, vanilla and sweetness are prominent. 

IDL also import a small amount of Virgin oak from America’s Ozark Mountains and it is used, for example, in Jameson Gold Reserve, very sparingly in Barry Crockett Legacy. We came across it also when tasting a Pot Still 8 year old (where it was the only wood used). Ciaran indicated that while it may not be used on its own “it will improve a blend. Lots of uses for it here.”

In the cask, the young spirits will have a strong distillate character. The longer it spends in the cask, the greater the influence of the wood, and the more complex it becomes. The task for the distiller is to strike a balance between the two. I reckon they get it spot (excuse the pun) on most of the time in Midleton.