My Country Living part II: the barrel-making process

This week’s My Country Living features cooper Killian O’Mahony from Co Cork.

He works for Irish Distillers in Midleton Distillery, inspecting and repairing barrels used for whiskey maturation.

The barrel, he explains to Irish Country Living, plays a huge role in developing whiskey’s characteristics. The process of making the correct barrel starts from planting the tree.

In Midleton they mainly use second-fill American oak barrels.

In his own words, Killian shares a little more about the barrel making process:

"I’ve a serious interest in what the barrel actually does, the different compounds and the connection between wood types and imparting their characteristics on to the whiskey itself.

"The barrel-making process is vital from day one to the end product, the whiskey you’re making. It doesn’t start when you’ve the timber ready to make into barrels. It starts from an acorn, it starts from when the tree is growing.

"To harvest an oak tree into a barrel, depending on whether it’s European oak or American oak, would be 90 to 110 years before you can harvest it."

"It’s quite a bit of patience and quite a bit of time, but over that time the tree has to grow in a specific way. It has to be almost managed and nurtured, because if you get twisting in the tree as it’s growing, you’re giving way to grains.

"What you’re trying to do is control the grain, so that it runs up and down the tree throughout its life. Then when it comes to harvesting the timber, again you're controlling the grain in such a way that it’s running 90 degrees basically, up and down the barrel.

"The rings in a tree that we would use to count the age are like little micro tubes running up and down carrying nutrients around it. So we’re trying to get them running up and down the barrel, because if they were running from outside to in, the whiskey would filter out of the barrel.

"Even down to that early, early stage, down to the felling, every step of the way has a final impact on the whiskey.

"When it gets to the actual barrel-making process itself, the American oak barrels are obviously made in America, for the bourbon industry. But bourbon has to be matured in a virgin American oak barrel. So it can literally only be used once, after they’ve been used for three years in the States, they’re sent over to us and we use it then, about 150,000 a year.

Charring

"Making the barrel, there’s a charring process. When we’re bending the barrel into shape, we’re doing a thing called charring. That’s using fire and water to bend the timber.

"In using the fire you char the inside of it, so you kind of blacken it. But what you’re doing is you’re opening up and almost cracking the timber on the inside, blistering it so the spirit can enter in and out.

"You’re also cooking the compounds in the oak and they break down into things like lignin and tannins.

What you’re doing is you’re opening up and almost cracking the timber on the inside, blistering it so the spirit can enter in and out

"When the whiskey finally meets the wood, it goes into the warehouse for maturation. Through the seasons the whiskey is expanding and contracting. When it’s expanding it’s literally entering into the oak itself, and when it’s contracting the compounds change the colour of it and mature the flavour of it.

"It changes everything about it. It goes in as new make spirit and then, however many years later, it’s whiskey, because the wood has imparted all of its characteristics on it.

"It’s such a lengthy in-depth process that starts from day one, growing the tree to cutting the tree and charring the timber, all that goes into the final product in the bottles."

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