Have you ever wondered just how important barrel ageing is to whisky? Do barrels make a difference?

In this exclusive feature, our resident whisky judge and expert, Luke McCarthy has dived into the world of whisky casks to find out the answers.

You can read more of Luke's features here.

Making whisky is a fairly straightforward exercise. You take three of the cheapest ingredients available to us - cereal grains, water and yeast, create a beer from them, distil that, fill the resulting spirit into casks, and wait for time to work its magic.

And yet, it’s that last part, the years of maturation in casks, that most drives the obsession of distillers, whisky lovers and anyone engaged in selling and marketing whisky.

How influential is the cask to the final flavour of a whisky? And what does the wood type, the previous liquid inhabitant, even where the whisky is matured, add to the equation?

For over 2000 years, we’ve been learning about these intricacies as casks have been used to transport and, ultimately, flavour wines and spirits. But it wasn’t until the end of the 1800s that the first laws appeared, mandating cask aging for spirits like whisky. Distilling industries and governments began to recognise the critical role maturation played in removing unwanted volatile alcohols and immaturity in the spirit while, at the same time, adding the flavours we’ve come to love in complex whiskies.

Australia has serious form here. Since the Excise Act 1901 was introduced, it’s been law in Australia that any whisky produced locally must be ‘matured by storage in wood for at least two years’ – a stipulation that predates similar regulations in the UK by almost two decades.
Since then, and even well before, whisky has been matured in every type and style of cask in Australia. But with the recent rekindling of the local spirits industry, Australian distillers have been taking things to another level.

One man, in particular, has been critical in helping distillers to up their game. Darren Lange is the founding director of Master Cask, the largest supplier of oak barrels to the Australian spirits industry. He has over 30 years experience in the wine industry, over half of those in barrel supply. With Master Cask, Lange is looking to bring a more sophisticated approach to whisky maturation in Australia.

'We don’t just focus on selling a cask. Selling a cask is probably the smallest part of what we do,' says Lange. 'The most important part of what we do is sourcing, and understanding the characteristics of that source. That tells us what we need to do in the cooperage, and then, ultimately, how the distiller is going to apply that cask in the maturation process.'

Lange believes that up to 80 per cent of the overall flavour of a whisky comes from the cask it’s matured in. So naturally, when you’re the guy supplying the casks, you’re going to emphasise their importance. But beyond that, Lange is determined to help Australian distillers produce world-leading whiskies by using what we have in our own backyard - Australian ex-wine casks.

'I come from a wine background, and I’m trying to bring the nuances and complexities that we understand in building complexity in a wine to whisky maturation.'

Over the last ten years, Lange has been sourcing and re-coopering casks for Australian distilleries that previously held Tawny, Apera, Topaque and Muscat, some of them for 60 to 80+ years. In collaboration with wineries, Master Cask have also developed patented cask treatment programs to ensure Australia’s iconic fortified wines remain a part of the journey as old cask supplies dwindle.

'Look at Scotland, they don’t have a wine industry,' says Lange. 'They’re completely reliant on sourcing casks from somewhere else. And that’s the exciting bit for me going forward. Utilising the incredible flavours we have in our fortified wines, inserting that influence into the cask, and helping Australian distillers to be recognised internationally for innovation and outstanding quality.'

Another winemaker in the Australian whisky industry is singing the same tune. Heather Tillott, the award-winning head distiller of Sullivans Cove Distillery in Hobart, started her career as a winemaker before switching to distilling. Now, she utilises that experience to select only the best casks for maturing Sullivans Cove spirit.

'I spend a lot of time on the road talking to winemakers and handpicking casks, because we endeavour to show the greatest respect to both the producers and the barrels we mature our spirit in.'

Tillot says the provenance of the barrel, the specific type of wine it’s previously held, and whether it hails from Tasmania, the Riverina or the Barossa, can determine everything from the cut points in a spirit run to how that barrel might be toasted or charred.

'It’s all about the relationship and respecting the history and the importance that these casks represent. Ultimately, we’re doing the same thing as winemakers but with slightly different ingredients, so there’s so much room for synergy and partnership moving forward.'

But how do the rest of us interpret all this complexity to select the whiskies we’re after?

Brooke Hayman has one of the best skill sets for this task. She’s the co-founder and business director of Whisky & Alement, one of the country’s top whisky bars, and has spent years sampling and selecting casks for various independent and in-house bottlings. She says that understanding how a cask might influence a particular style of spirit is crucial.

'There’s a balance that needs to be struck between the cask, ensuring that it doesn’t dominate the base spirit character or become too oaky and tannic, and the flavour character from the previous fill, particularly in today’s climate where so many fun casks are available for maturing and finishing,' Hayman says.

She also thinks closely about age when selecting whiskies for her customers, but says producers around the world, like those in Australia, are forcing a rethink.

'Australia is a land of extremes, and because distilleries are located right across the country, many experience their own microclimate. Our hot days and cold nights see maturation accelerated compared to the cold and temperate climate of the UK. Time in cask is still a key indicator of flavour, but it’s becoming less important as maturation moves to different locations around the world.'

You sense this is just the start. Like other new world whisky producers, Australia is finding its way with casks and maturation conditions unique to this country. Some of the results are already in, while other experiments will take years to reveal their secrets.

Either way, there are plenty of new discoveries to look forward to.