“Madeira casks add fruit such as apricots and summer cherries with sumptuous juiciness, together with vanilla, hints of clove, liquorice and aniseed. These spices add softness and freshness which rounds out the flavour,” says Stephanie Macleod, Dewar’s master blender.
Casks are usually sourced through a cooperage rather than directly from a Madeira house, either as ‘ex-ageing stock’ taken from the inventory, or ‘seasoned to order’ when the distiller stipulates the style of Madeira and length of the seasoning period, as well as the cask’s credentials. This includes the size, typically a barrique (225 litres) or butt (500 litres), and either American or European oak.
“We tend to use American oak casks as they are more abundant and consistent, though European oak has a more open grain, enabling the spirit to penetrate the oak more readily and gain a greater influence in a shorter period than American oak, which has a tighter structure. When used for finishing, European oak and smaller cask sizes have the greatest influence, but for full-term maturation the oak type is not so significant,” says Stephanie Macleod.
Each time a cask is ‘filled’ (used) its influence evolves, and with Malvasia casks more readily available than other styles, this provides a test case. Loch Lomond’s Islands Collection Inchmurrin Madeira, for example, is a 10-year-old malt whisky some of which was finished in first fill Malvasia Malmsey casks for 6 months, and some in second fill Malvasia Malmsey casks for 12 months.
“Madeira wine soaked into the wood is the greatest influence, and more of this comes out in a first fill than a second fill. The first fill gives richer figs, dates and citrus, while the second fill has milder fruit but more pronounced nuttiness. This adds to the Inchmurrin house style, which has distinct peach, pear and orchard fruit,” says Michael Henry, Loch Lomond’s master blender.
And that’s what really matters: how the influence of the cask interacts with the house style.
“Bacalta was the result of finishing 10-year-old Glenmorangie for up to three years in Malvasia Malmsey casks, which enhanced Glenmorangie’s classic citrus notes, turning lemon into chunky orange marmalade. Madeira casks also added lots of marmalade on buttery, slightly burnt toast, white chocolate, toffee and mint. The result was classic Glenmorangie, but with a different balance,” says Brendan McCarron, Glenmorangie’s head of maturing whisky stocks.
The influence of casks that aged another style of Madeira is showcased by Glenmorangie’s Grand Vintage 1993, which spent 10 years in Bourbon barrels, then 15 years in Bual casks.
“Such a long finishing period was possible because the oak was less active, and the result was incredible poise and balance between the influence of the Bual cask, adding peaches and apricots, while retaining the classic Glenmorangie style,” says Brendan McCarron.
Combining the influence of Bual and Malmsey casks provides additional opportunities. Both were used to finish Aberfeldy 16 and 21 Years Old, adding caramel, peaches and orange peel to Aberfeldy’s honeyed richness.
As malt whisky is continually evolving within a cask, how do master blenders decide when it’s peaked?
“Instinct and experience. We write massive amounts of tasting notes when sampling, and looking back at previous tasting notes helps you decide which direction it’s going in, and a sense of the rate of change, faster or slower,” says Brendan McCarron.
As ever, it’s about achieving a balance.
“Madeira has a very appealing sweetness, and toasted, nutty oak flavour which adds another layer of complexity and nuance. The cask must complement the whisky, not compete with it; the lead flavour must be from the whisky itself,” says Sandy Hyslop, director of blending at Chivas Brothers.
With Madeira casks offering a distinctive influence, will we see greater quantities arriving in Scotland?
“I haven’t come across a malt whisky yet that hasn’t benefitted from spending some time in Madeira casks. They come together really well, like interlocking fingers, and something lovely comes out every time,” says Stephanie Macleod.
Different Styles of Madeira
Specific grape varieties are used to produce different styles of Madeira, including Malvasia, which yields the sweetest and richest wines. Bual is classed as medium-sweet, Verdelho medium-dry, and Sercial is the driest.
When trialing a particular cask type, the potential influence on a malt whisky can be gauged beforehand.
“I get a bottle of the product that was aged in the cask, rinse a glass with it then fill the glass with malt whisky, and this gives me a good indication of what to expect,” says Stephanie Macleod.
Having committed malt whisky to a cask, it’s then a case of regular monitoring.
“I’m exploring casks more than ever during my 30 years in the business, and I sample any wine cask experiments weekly to check the level of pick up, so that I can stop it whenever I wish. The rate of development depends on various factors; it’s vital, for example, to fill the cask on arrival while it’s still fresh,” says Sandy Hyslop.