The whisky virgin

How does a cask’s background impact whisky?


All Scotch must be matured for at least three years in an oak cask, but the often complex history of that vessel can greatly influence the spirit’s flavour, as The Whisky Virgin discovers.

Assorted casks in a warehouse
Barrel breakdown: The Whisky Virgin wraps his head around different cask types

Tripping through the whisky-verse this last year or so, I’ve learned that if you want to make Scotch whisky you need grains, water and yeast. What I only got wise to recently is that this modest shopping list of fixings will only get you part of the way – without ageing your product in a barrel, all you’ve got is spirit. It was on a recent trip to Campbeltown in Scotland’s western extremities that I was reliably informed that if you want to evolve that spirit into whisky you need to let it level up in an oak cask for at least three years. Simple? You better believe it isn’t. Turns out the backstory of a cask can have a big impact on what kind of whisky you wind up with.

Now I’d heard chat about Sherry and Bourbon casks but I didn’t realise that whisky flavour had so much to do with wood. But what can I tell about how a dram is going to taste from the kind of oak it used to live in? Does cask type really matter, or is it just to add a bit of colour and give the whisky cartels something nice to write about on their boxes? And more to the point, will I be able to grasp all the different types of wood in the world without resorting to double entendre to elicit cheap laughs?

US rules: Bourbon distillers like Woodford Reserve must age their whiskey in charred virgin oak casks

I feel like I remember from my Bourbon adventures on Thanksgiving that a lot of used American oak barrels come to Scotland for a second chance at usefulness. Something to do with American whiskey makers having to use new oak – which makes their spirit all sweet and vanilla-y – while their Scottish cousins prefer a cask that’s been around the block and been mellowed by experience. What I didn’t know before this month’s drinking research is that as much as 90% of the barrels in Scotland come direct from the US-of-A. They arrive in the land of Scot bringing flavours of butter, vanilla and coconut, and strong ideas about the role of centralised government. Turns out every time I had my nose in a dram and sniffed some vanilla it probably came from a Bourbon cask.

Word on the street is that the second big player in whisky wood is the Sherry cask, made of Spanish oak and turned sweet and tasty on the inside by the official wine of tapas. I got to knocking down a few Spanish-accented drams in the name of research and I reckon they tend to be on the richer side of things. Some were sweet, fruity and a little nutty – like your nana – and others were salty, dry and smelled a little like cigars – like my nana. Bottom line is, if I fancy something a little thicker and ‘digestif-y’ when I’m doing some ‘drammage’, it could be that Sherry cask hooch is what I need. Good to know.

Versatile wood: Brewers also often use oak casks to condition their ales

Ex-Sherry and Bourbon casks might be home to the majority of Scotland’s ageing whisky stocks but apparently that is by no means the whole oaky picture. Turns out the booze business worldwide uses oak to add flavour and complexity to all kinds of spirits, wines and beers. Creative whisky makers looking for fresh moves to drop on the Scotch-swilling public are apparently looking all over for interesting oak to vary up the game. Rumour has it, Port pipes from Portugal, Cognac barrels from France and IPA casks from England are all being shipped up to Scotland to house would-be whisky and change its flavour.

The crazy part is that whisky slingers look like they’re having a lot of fun using multiple cask types in single expressions. At my local whisky den I found a GlenDronach 12-year-old, aged in two types of Sherry casks for extra flavour; a Balvenie DoubleWood, which starts out in American oak but then gets poured into Sherry casks to ‘finish’ it off; and a Springbank 21-year-old – about 70:30 rum cask to Bourbon cask, all mixed together like some kind of beautiful internationalist metaphor.

I even managed to cop a slurp of cutting-edge, genre-bending whisky from Glen Moray aged in casks flavoured with cider. Sounds weird? It was a little. But one sniff of apple-scented Scotch and I was in there like a wasp at a picnic. If you fancy something sweet and autumnal that tastes a little bit like a Halloween party getting out of hand then I can totally recommend it.

During my research session I think I also discovered a kind of oak arms race going on where different brands were fronting about how many cask types were used in making their signature brews. Auchentoshan Three Wood sounds good, right? But Jura Seven Wood? Simple maths tells us that’s got to be more than double the woody deliciousness, right? I even heard a rumour that Jura scientists are working on eight-wood technology that will render Seven Wood obsolete?

The stuff of fanciful science fiction? Maybe for now.

Numbers game: Do more cask types equal better quality whisky?

What I can say for sure is there seems to be a lot of talk about oak right now in the whisky world and a lot of desire to mix things up. Don’t they age Tequila in barrels? Could we see a tequila/whisky mashup in the future? Isn’t there a cheese they do in barrels in Greece? What would a feta whisky be like? Probably not great, actually, but then again you never know. The whisky keepers at my local tell me that for now the guardians of all things malty, the Scotch Whisky Association, say that only casks used historically are on the table for Scotch ageing, but in the future…

Anyway, my take-home this week is that if I know what types of cask were used to age a Scotch I can get a slightly better idea about what it will taste like. It’s good information to have when making a booze decision, but I reckon thinking of one type of wood, or combination of casks, as better than others isn’t the way to go. Is red wine better than white wine? IDK mate, probably depends on what you’re having for dinner.

Does that work as a metaphor? To be fair, I know even less about wine than I do about whisky. I had to google what a Port barrel was called for that bit about wine casks earlier. A Port pipe? Who knew. Anyway, I’ll catch you next time whisky pals. And if you do see a Jura Eight Wood out there, you let me know, okay?

Scroll To Top