This July Outturn, we’re all about the influence of the bourbon cask on the world of Scotch whisky. Here’s SMWS spirits manager Euan Campbell on what the humble hoggie brings to our bottlings

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We have no shortage of variety when it comes to the casks that we use at the Society, with more than 70 different types in our warehouse the last time I checked. They range in size from 125 litre ‘quarter casks’ to a 600 litre port pipes and have undergone different toasting or charring treatments. Around 20 per cent are sherry butts or hogsheads, seven per cent are some form of cask created to a customised recipe and about two per cent fall into the ‘other’ category of ex-rum, armagnac or something else similarly exotic.

That leaves the bourbon cask as accounting for around 70 per cent of our warehouse stock – and there’s very good reason why so much Scotch is left to mature in wood that previously held bourbon, whether it’s a 250 litre hogshead or a 200 litre barrel.

SMWS spirits manager Euan Campbell gets hands-on with some ex-bourbon casks at Bladnoch distillery.

For me, a long period of maturation in subtle wood such as a refill hoggie results in my favourite style of whisky, allowing the distillery character to shine through – although it demands patience.

A great example of your patience being rewarded in this month’s Outturn is with our Old & Dignified flavour profile Cask No. 7.238: The problem of reality. It’s a lovely clean Speyside distillate which has been resting in a refill hogshead since 1993 and at that age it’s as rare as hen’s teeth. The Tasting Notes transport us to driving a Sunbeam Alpine convertible along the Cote d’Azur, and if the bottle name sounds like it could cure an existential crisis, it could be exactly what we need in current times. Stunning.

Cask No. 41.132: A paradise of spice is an interesting comparison. Although it’s also in a refill hoggie where you might expect a light wood influence, this one is in our Deep, Rich & Dried Fruits flavour profile, and also resulted in a lovely amber colour, even at 11-years old. It’s much darker than you might expect and full of lovely ginger, rum and dark fruity flavours.

Together, the two Speysiders reflect different spirit styles and ages, with the 41.132 coming from a distillery that uses worm tub condensers, giving a heavier, meatier spirit.

On the peaty side of things, we have an intriguing pairing between Cask No. 10.194: Maritime marshmallows, and Cask No. 66.173: Dali’s melting tractors. Cask No. 10.194 is from our less frequently seen Heavily Peated flavour profile, coming from the peated variant of the spirit (between 35-45ppm, or parts per million of phenols) from distillery 10. It’s been matured in a recharred hogshead, so it’s probably been used more than your standard refill hogshead but still yields a beautiful whisky. Its heat treatment has imparted a lovely deep colour and unlocked the flavours and the colour that was still lurking in the wood, and recharred wood and the heavy peated spirit have conspired to make this a fantastic ashy smoke fest of a dram.

By comparison, Cask No. 66.173 is Lightly Peated and comes from a refill hoggie, with malt peated to a lighter level of 12-14ppm, as I found out on a memorable visit to this Aberdeenshire distillery in 2018. Explore these different levels of peatiness and the influence of peat from different regions – Aberdeenshire and Islay – in these whiskies where the casks still let the peat do the talking, without either bottling being overly oaky in character.

In the last Outturn I was looking at some interesting contrasts and recommended setting up an aged single grain with a mature single malt – and there’s another great opportunity this month to do something similar. Cask No. G8.12: Amuse-sploosh! is a 29-year-old single cask grain gem from a now-closed Lowland distillery, matured in a refill hogshead and with the notes of toasted coconut, lemon rind and barley sugar that you’d associate with our Juicy, Oak & Vanilla flavour profile. Cask No. 46.95: Tripping in the Blue Peter garden, meanwhile, is a beautiful 27-year-old refill hoggie from Speyside, with the aromas of dried wildflowers, lemon-scented wax candles, gorse and chamomile.

One more intriguing comparison would be to look at two bottlings from the same Spicy & Sweet flavour profile but from different sizes of bourbon cask. Cask No. 36.174: Bircher muesli almost ‘complet’ is from a refill hoggie, whereas Cask No. 63.67: ‘French four spices’ is from a first-fill barrel. It has a higher wood influence from the slightly smaller and more active barrel, whereas the 36.174 has more cereal sweetness – and together they show the diversity on display even within the same flavour profile.

Some other bottlings to relish in this month’s Outturn: Cask No. 1.223: Dessert triptych : mushroom sorbet, a beautiful deep, dark refill oloroso sherry butt and Cask No. 113.31: Push pineapples shake a tree, which is a Speyside bottling from 1997 that we rarely see from this distillery at that sort of age. Check out Cask No. 138.7: Raw sunflower honey for an unpeated whisky from Taiwan that exhibits all that lovely tropical aging character we love from that island’s spirits. Last but not least, we have a second release of gin from Northern Ireland with GN4.2: Nettle smooch, which also had a period of maturation in a first fill bourbon barrel.

Whatever you pick up this month…raise a suitable glass to the gift of the bourbon cask. Where would we be without it?