Why Irish whiskey loves sweet and fortified wine casks

Redbreast’s latest release in its Iberian Series is the Moscatel Wine Cask Edition. It’s the most recent in a long list of Irish pot-still whiskeys finished in a sweet, fortified-wine cask. And it’s not just pot-still. In 2025, Jameson blended whiskey released its Triple Triple Marsala Cask Edition, and Bushmills replaced its 10 Year Old malt with a Marsala-finished 12 Year Old, so that its entire single-malt range is now sweet fortified-finished.

Far more than Scotch, which tends to stick to Sherry, Irish whiskey in its various forms has been finished with success in an array of fortified wine casks. Why the affinity?

A little bit of history repeating

Dave McCabe, Irish Distillers’ Master Blender, responsible for Redbreast, says: ‘Our master cooper, Ger Buckley, told me that bourbon casks didn‘t arrive at our Midleton distillery until the 1960s – before that it was all Sherry and other wine casks.‘

In the 1800s, there was a lot of sea trade between Ireland and the Mediterranean. Whiskey bonders (who bought new-make spirits from distilleries, aged them and blended them) were wine merchants too, so it was logical what they would use. And fortified wine was best suited for ship transport.

Michael Cowman, co-founder of independent bottler Redacted, points to older connections. ‘There’s a straight line from northern Spain to the west coast of Ireland. It’s been a smuggling route, a fishing ground for Spanish ships. And there are the Catholic alliances – a lot of Spanish settled on the west coast after the Armada was wrecked off the coast.’

McCabe says: ‘You can take it even further back, with the Irish involved in setting up monasteries around Europe, where they produced wines.’

That explains the tradition. But why does it work so well?

The right spirit

Pot-still whiskey, claims McCabe, is ideal for a dessert- or fortified-wine finish. ‘The inclusion of unmalted barley adds a mouth-coating, creamy texture. When you age that in a PX or Moscatel wine cask, which has a sugar content of between 200g/L and 400g/L, I think there’s a level of decadence. When it comes to dessert wines in Spain, they mightn’t even drink them – they’ll pour it over ice cream as a syrup.’

Irish single malt does not have the Robinson’s Barley Water element of pot still at the raw spirit stage, as Bushmills brand ambassador Janice Snowden points out, but that doesn’t seem to be a hurdle. ‘The 12 Year Old Marsala finish has texture but the tears on the glass are from the finish... We’re not about making a really gooey new-make spirit – it’s more medium-bodied than oily.’

Arguably one of the most contentious finishes in Scotch is Port (particularly ruby Port), which can taste like someone spilt blackcurrant jam in the bottle. But the Ribena note on Port-finished Irish single malt is not as jarring.

‘Even before I worked for Bushmills,’ says Snowden, ‘the 16 Year Old was my favourite Irish whiskey. And I have yet to find a Scotch whisky with a Port-cask finish that comes close to it. It’s not overwhelming; it just complements the spirit character – especially those red and green apple notes of the new-make.’

Make it a triple

What Irish single malt and pot still share is triple distillation. Alex Huskinson, WSET Educator for The Whisky Exchange explains: ‘Triple distillation in Irish whiskey isn‘t the same as for vodka – they’re not aiming for a neutral spirit. But it does result in a brighter, more fruity spirit.’

He adds: ‘If it’s a single malt, it concentrates the malt character... nuts, honey, citrus. For pot still, the unmalted barley will give you green notes and fresh spice. Triple distillation hones in on flavours which will be enhanced by sweet wine influence.’

Some Scotch malts will work with these wines, but often whiskies that are umami-rich or smoky, for example, clash instead.

Cowman, who bottled a Sauternes-finished Dingle whiskey in 2023 adds: ‘I think triple distillation gives you a really good canvas to paint on, as long as you select really good casks to finish in.’

Quality casks

And that is key. Like all matters in wine and spirits, the modern level of detail, sophistication and quality control is a world away from 19th-century traditions of trading casks at the quayside.

‘If we just bought old casks a bodega was trying to offload, we would get all the sweetness from the wine, but without that nicely balanced tannin from the oak,’ says McCabe. ‘That‘s why we work directly with bodegas to produce bespoke casks seasoned with the fortified wine.’

For Redbreast‘s Moscatel edition, he worked with Bodegas Quitapenas in Málaga, which took toasted European oak hogsheads and seasoned them for two years with a wine chosen from a selection of 30, before they were shipped to the distillery in Cork.

Variety is the spice

The sheer range of different fortified and naturally sweet wines – even from individual winemakers – is exciting for whiskey makers. Both Snowden and McCabe get animated when talking about the estufagem heating process in Madeira (leaning towards stewed apricots) or Marsala‘s addition of mosto cotto (cooked grape must, giving whiskey extra nuttiness and tobacco).

Cowman is a champion of the less global Irish whiskey makers. He has tasted limited editions finished in Vin Santo, ice wine and Rivesaltes casks. At the moment, he is searching for a good Hungarian Tokaji cask to finish a whiskey in. ‘There are lots of possibilities if people are prepared to push the envelope on what’s possible,’ he concludes.

Six sweet fortified-wine cask Irish whiskeys to try

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Boann Single Pot Still Irish Whiskey Madeira Cask

Boann distillery in Meath is an envelope-pusher extraordinaire. Its core pot-still range is all fortified-wine-aged (Madeira, PX and Marsala) and it’s tough to choose the best. Justino’s Madeira Wines has supplied casks from various vintages and colheitas, as well as the different Madeira styles – including boal and sercial – for an exquisite balance of peaches and cream, floral aromas, walnuts and fruit cake. Alcohol 47%

Bushmills 12 Year Old Single Malt

With only a six-month finish in Marsala casks, you might expect the first 12 years in oloroso and bourbon to have more influence here. But the fresh apple notes are caramelised, there are candied nuts, honey and spices... It’s a remarkable step up from the old 10 Year Old. Alc 40%

Jameson Triple Triple Marsala Cask Edition

Jameson is a blended whiskey, combining pot still and grain whiskey – the latter is also a good canvas for flavour. The triples refer to the distillation of course, and three woods: bourbon, Sherry and American oak seasoned with Marsala from Cantine Florio in Sicily. It gives an exotic twist to the original Jameson, with banana, kiwi and ginger notes. The Marsala Cask Edition is exclusive to travel retail. Alc 40%

Redbreast Moscatel Wine Cask Edition

For this non-age-statement whiskey (believed to be at least nine years old), Master Blender Dave McCabe took liquids aged in ex-American whiskey and ex-oloroso casks and finished them for a chunky 16 months in Moscatel casks. It takes you on a citrus journey, with lime juice and bitter orange peel, plus creamy vanilla fudge and floral honey, with some pepper and allspice. Alc 46%

Red Spot 1991

Normally, Master Blender Dave McCabe would blend casks to balance distillery character, wood influence and the wine finish. But this rare single Marsala cask was all perfectly balanced and matured for 31 years, rich and fresh in equal measure. Expect apricots and peaches, tobacco and cocoa, prunes and raisins, with a scattering of herbs and spices. Exclusive to The Whisky Exchange. Alc 55.9%

Two Stacks 9 Year Old Single Pot Still Cab Franc Ice Wine Finish

Two Stacks is one of the new era of Irish whiskey bonders, a movement revived by JJ Corry a decade ago. For this release, they gave a pot-still whiskey (understood to be from Great Northern Distillery) a long, 18-month rest in barrels that previously held Cabernet Franc ice wine from Canada. Name a red berry or plum variety and it’s in here, but with great tannic structure and wood notes to avoid excessive jamminess. Alc 54%

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