Innovative cask selection provides two valuable opportunities, enhancing the flavour profile of the resulting malt whisky, while also giving the distiller (and marketing department) a story to promote. And with malt whisky fans now accustomed to continual innovation, their inevitable refrain is what’s next ?“The motivation for me is we should always aspire to make ever greater whisky, as our understanding of how to make great whisky improves and techniques improve.It’s not so much innovation but challenging the way we do things, to see if there’s a better way, within certain parameters,” says John Glaser, who has won Whisky Magazine’s Innovator of the Year award four times.Whyte & Mackay’s Richard Paterson adds, “Ablender has to be innovative and make his products exciting and vibrant, so he’s going to experiment with a lot of casks and different styles of malt. But you must never let casks dominate your whiskies, the character of the whisky must come through.” This raises the question of how a particular type of cask, and the influence it has to offer, will interact with different styles of malt.“Whenever I’m choosing casks I always ask, will this be compatible with the age profiles of any of my whiskies, and you know instinctively whether it will work. Not all malts will have a love affair with all casks, and you need to have a whisky that’s compatible with the cask,” says Richard Paterson.Glenmorangie’s Dr Bill Lumsden continues, “Glenmorangie is a great whisky to use for two reasons, being prestigious itself, and also lending itself to finishing, being very lightly peated as well as very soft and delicate, which means it has a lot of flavour that’s complemented by wine notes, while the softness allows the malt to pick up those notes.” Once the casks have been selected and filled it’s merely a question of time. But trying to anticipate a cask’s ‘schedule’ for delivering an influence is another matter.“The time it takes to reach a result is the least exact part of it, as you have to wait and see. I sampled the 1981 Sauternes Finish after three months, and then six months, and there was next to no change. Then after a year I was delighted with the luscious flavours that came through,” says Bill Lumsden. On the other hand a cask’s influence may show very quickly. “Sometimes I monitor a cask every week, as every week it takes on additional nuances from that cask, and several weeks might be enough,” says RichardPaterson.How a cask influences maturation depends on various factors. This includes the ‘fill’ (whether filled for the first, second or third time – the cask’s influence diminishing and changing with each successive fill), and the nature of the cask’s previous occupant, if any. Whether the oak is American or European is another factor, in conjunction with the cask size, the aging environment, and of course the length of aging.Maturation can be divided into three elements: subtractive, additive and interactive, which occur simultaneously although at differing rates.Subtractive maturation deals with the loss of immaturity, while additive maturation sees the oak endowing the spirit with colour and character.Interactive maturation refers to the complex reactions occuring between the spirit and the oak, creating an additional range of characteristics that neither possess individually.As the balance between the distillery character embodied in new make spirit, and the influence of aging, is continually evolving during maturation, where the best balance lies between these two aspects ultimately depends on the master distiller, not to mention your own personal preference.As a key pioneer in innovative cask selection, Bill Lumsden has driven Glenmorangie’s extensive range of special finishes.“In 1998 I moved into a new role in which cask selection was one of my key responsibilities. My starting point was a combination of using casks from wines that I’d enjoyed, and very high pedigree wines that I’d read about, so I thought if I could get the barrels from these winesthere would be a really nice flavour and exclusivity for that product. You take an instinctive view of what you’re going to get,” says Bill Lumsden.Among recent innovations in secondary maturation, Compass Box released Oak Cross last September. The starting point was malts aged for a minimum of 10 years, a proportion of which were subsequently transferred to casks comprising American oak bodies, while new, unused French oak with a specific toasting level was deliberately limited to the heads.“I didn’t want a hit of oak, I just wanted a kiss of oak. Coopers will tell you there have been examples of mixed oak casks in the past, either by accident or by design, due to practicality, so they’ve had a good precedent in the industry over time,” says John Glaser of Compass Box.And the verdict?“We’ve had tremendous feedback from traditionalists, and progressives, that this adds a lovely flavour to the classic distillery character, and that it’s elegant and refined but with a bit more going on,” adds John Glaser.Meanwhile, two 17 year old bottlings Issue 63 | WHISKY Magazine | 63 Whisky production In association with anCnoc of The Balvenie, NewOak and NewWood, have featured the use of new American oak casks,toasted and charred but not previously filled with any liquid, for a secondary maturation period.“We had a lot of experience using new wood in our Solera, so we knew what it could do for Balvenie and how long to keep it in the cask. New wood adds more colour, slightly more spicy oakyness, sweet vanilla and fruityness. We monitored casks every four weeks, and after the first four weeks the colour had darkened and there were slightly more oaky notes, with vanilla sweetness starting to come through. After eight weeks there were further changes. If we’d left it for longer than four months the oakyness might have counteracted the sweetness,” says William Grant’s David Stewart.Apart from casks with an innovative provenance, another approach is using different sized casks, as in Laphroaig’s Quarter Cask. This sees Laphroaig matured in bourbon barrels subsequently transferred to ‘quarter casks,’ which at 127 litres represent a quarter of the size of the largest butts (with quarter casks used in the early 19th century). This promotes greater contact between the spirit and the oak, which influences the rate of maturation and resulting character.“The casks add more body, this imparts a flavour that gives more creaminess, and you also get a dry finish,” says Laphroaig’s John Campbell. Of course there’s no innovation without experimentation, which means this is an on-going aspect of the industry.“We have one warehouse at Glenfiddich and one at Balvenie, where we stock experimental casks that we check every month, and keeping them in a couple of warehouses makes it much handier to check them,” says David Stewart.So, with the industry having already achieved so many innovations in cask selection, what else is there that can be introduced in the future ?“Using very specific casks from a particular chateau is one way forward, and in terms of being cutting edge I still think there’s an opportunity, though I wouldn’t say there’s plenty of opportunity. I think there will be more focus on other parts of the production process, and that’s already happening,” says Bill Lumsden.