No longer content with a simple bourbon barrel, whisky distillers are turning to sherry, rum, even premier cru wine barrels to enhance their spirit’s flavour, writes TOM BRUCE GARDYNE
One of the magical things about single malt whisky is how such a variety of flavours can be achieved from just a handful of humble ingredients by whisky distillers. By law you may use water, malted barley and a little yeast – nothing else. There are different strains of barley as there are for grapes, but the effect of choosing one over another is at best marginal – certainly nothing on a par with wine. With single malts the diversity occurs later, not in the few days of being turned from grain to spirit, but in the long years of maturation in oak. What dribbles off the still gives you the distillery character – the whisky’s DNA if you like. What happens then, during the slow, complex interaction in the cask, is what makes each single malt unique. Today the most experienced hands in the industry, people like whisky distiller Diageo’s Dr Jim Beveridge, say that a good two thirds of a malt whisky’s flavour derives from maturation.
Not so long ago, whisky distillers would have dismissed such claims as absurd. It was what they did in the distillery – how they coaxed the precious nectar from their stills – that counted. Thereafter it was little more than storage. Barrels were simply secondhand containers. There was even a story, probably apocryphal and no doubt peddled by a disgruntled rival, that one Campbeltown distiller used old herring barrels. The result would have been extremely unpleasant.
A lot of scotch was matured in sherry butts until the 1960s when a change in the rules for American whiskey meant whisky distillers there could no longer re-use their barrels. Before long the Scotch whisky industry was maturing 90% of its spirit in ex-bourbon casks. Not everyone was convinced, however. ‘We saw that using casks seasoned with sherry gave us a particular, desirable flavour,’ says David Cox of Macallan. ‘It works particularly well with the heavy, oily spirit we produce.’ The distillery now has its own bodega in Spain to control how the wood is cut, seasoned and toasted. As for fillings, ‘we tend to specify dry oloroso’, says Cox. Today sherry butts account for the remaining tenth of the needs of whisky distillers.
But in the last decade, distillers have been peering into their old ledgers where the rag-bag of casks once used are faithfully written down. What if a whisky that had matured in an ex-bourbon barrel were given a few months in something a little more special?
‘We realised that what was soaked into the wood had a big impact,’ says Dr Bill Lumsden, Glenmorangie’s master distiller. Having experimented with different casks since the late 1980s, the company released the Glenmorangie Port Wood Finish in 1994. For the next in the series he looked beyond Oporto to Madeira and managed to secure a few old casks. ‘It’s the most complex of our wood finishes – more tart fruits than the raisins and dates you get with sherry,’ says Lumsden. These two, plus a sherry finish, are Glenmorangie’s core range of wood finishes and are widely available.
William Grant & Sons also helped pioneer the fashion for wood finishes with The Balvenie Double Wood, which spends its last nine months in an oloroso cask. This gives the classic Speyside an extra dimension and some of that rich, spicy, fruitcake character you get from an active sherry butt. A shorter finish is given to The Balvenie Port Wood 21 years old. ‘We don’t want the port pipe to overpower the whisky – it’s a case of working with the flavour and rounding it off with a silky smooth texture,’ explains Jens Tholstrup, brand manager for Balvenie and rare whiskies.
On Islay various malts have gone to finishing school. Bowmore Darkest is aged for two years in a fresh sherry cask to overlay flavours of nuts and raisins on the peat-smoked character. Meanwhile the Distiller’s Edition of Lagavulin spends just a few months in what Jim Beveridge calls ‘an active American cask, seasoned with Pedro Ximénez’. Using the sweetest of all sherries helps subdue the smoky intensity of the 16 years old Lagavulin – one of Diageo’s Classic Malts.
For the others in the range, Beveridge chose different casks like amoroso for Talisker and amontillado for Glenkinchie. ‘Cask finishes are about adding an extra dimension, but they’re also about closing down some of the fresh, vibrant aspects of malt whisky.’ He also believes that the type of oak the cask is made from is even more critical than its previous contents. American oak gives bourbon its sweet smack of vanilla, while the European variety is tighter-grained and far more tannic.
Bill Lumsden agrees the type of oak plays a big part but not necessarily more than the previous contents. ‘With port pipes I look for European oak with its astringent, leathery character,’ he says. ‘I want lots of port soaked in and no sour off-notes, so we nose every barrel.’ How much a cask gives to a whisky also depends on its age and how many times it has been used. This affects the length of the finish. With The Glenfiddich Gran Riserva, Jens Tholstrup reckons four months in a rum cask is enough to give ‘a trace of molasses and a touch of spice’.
Of course it is also about marketing. The Scotch Whisky Association (SWA) who regulate the industry take a keen interest, and distillers must submit new finishes for approval. For the Gran Reserva ‘we had to prove to the SWA that this was done in the past,’ explains Tholstrup. ‘There’s no doubt British sailors brought back barrels of rum to Liverpool and Glasgow and that whisky would have ended up in them.’ The SWA agreed.
What causes more concern is the use or abuse of provenance with terms like ‘Islay Cask’ for a whisky finished off in a barrel that once contained, say, Laphroaig. This sounds suspiciously like those sheep farmers whose flocks would spend a weekend in Wales for the added cachet and price of being ‘Welsh Lamb’.
Tom Bruce Gardyne is author of The Scotch Whisky Book (£10, Lomond Books).
Written by Tom Bruce Gardyne