There may be hundreds of whiskies you can choose to drink, but not many are made with the Solera process. Derived from the wine-making industry and improvised for whisky production, it’s a clever piece of ingenuity that imparts complexity, richness, and consistency. Thankfully it’s not something you have to search far and wide for, and may well be right under your very nose: it’s the Glenfiddich 15 Year Old (YO). With great thanks to William Grant and Sons (Singapore), we were given the opportunity to experience a rather fascinating tasting where the 15YO was ‘deconstructed’ into its component whiskies.

Irrefutable proof he is a bonafide scotch geek: Matthew has written extensively about the effects of chill filtration on whiskies for that most anoraky of anorak sites, Malt Maniacs. He is also one the foremost purveyors of whisky molecule porn.     (Photo Credit: Glenfiddich)


Taking us through this journey was none other than Matthew Fergusson-Stewart, Glenfiddich Brand Ambassador for Southeast Asia, and one of the most knowledgeable scotch whisky geeks you can find these parts. It was a rather refreshing experience as it was done via livestream from Warehouse 8 at the Glenfiddich distillery, where the actual Solera Vat is located.

Que Solera, Solera?

If you want a more detailed explanation about the process, thankfully the WWW is chock full of info. Or you can check out the links here, and here.

The Solera process originated from Spain and Portugal and is most commonly used in the production of Sherry and Port. It is also known as fractional blending. The idea is simple but the process can become rather complicated, depending on the scale of the operation and the method used. The picture below depicts how the spirit is added, transferred and removed; never at any time is any cask emptied in the Solera process.

solera system 1A simplified graphic of the Solera process (Picture credit:

The payoff for all your trouble is having less variance between batches and as such, a more consistent product. As the cask will contain spirit of many different vintages, the age is traditionally taken as a weighted average.

Glenfiddich’s method is a little less mind-boggling. The 15YO is made up of three components – whisky matured in ex-bourbon casks, whisky matured in ex-Oloroso sherry casks, as well as ex-bourbon matured whisky that has undergone a further four months of ‘finishing’ in new American oak casks. They are then introduced to the massive 35,000-litre Solera Vat to mix and settle. The ratio of the vatted malt is roughly 70% ex-bourbon, 20% ex-sherry, and 10% new American oak.

“We do this for a couple of reasons,” says Matthew. “Firstly it’s about consistency; now that is a very important process in whisky. It gives us a consistent product, and over time, gives us richness and complexity because of all the different batches put together.”

After mixing in the Solera Vat, half of the whisky is transferred to Portuguese Oak tuns to be married for at least three months, before it is chill filtered and diluted to 40% ABV with spring water from the Robbie Dhu.

Glenfiddich Solera Process 1The one-look, Glenfiddich Solera System primer (Photo Credit: Glenfiddich)

Drayman’s Distillery of South Africa does a traditional-style Solera blend using Scotch and South African-made whisky, but these are pretty hard to come by.

As Glenfiddich has chosen to bear an age statement on its bottling, the youngest whisky in the mix is always at least 15 years old; at time of writing, the oldest whisky in the mix is over 30 years old. In practice, it doesn’t mean that you’re paying 15YO money to get the ‘goodness’ of a 30YO whisky, but at the same time the older whiskies do go a long way in helping to temper and mellow the younger ones, as we soon found out while tasting the malts. At the very least, the idea that half the bottle is made up of older whiskies should be comfort enough anyway.

Solera VatThe 35,000 litre Solera Vat (background) is really massive (Photo credit: Glenfiddich)

As a large producer, Glenfiddich faces a constant challenge to deliver volume as well as maintain a high standard of quality. The Solera approach is actually a rather clever way to add a teeny little extra character to the whisky, which is good for us, and at the same time make a more consistent product, which is good for the distiller. It’s a happy middle ground in my book.

Component notes and thoughts

The Glenfiddich range has been long known for its distinctive apple and pear notes, and this is by no means an accident. Part of it is down to its longer-than-usual, 72-hour fermentation process, which releases more esters that give the spirit its signature notes.

Glenfiddich component maltsThe component malts in all their amber glory

The component whiskies were rather robust and exuberant, which is nice at first, but isn’t something you’d like to be constantly drinking. The whisky that was finished in new American oak cask, however, was an exception, as it was more balanced and felt more like a complete product. The surprising bit was how much better the vatted result was. It was significantly more refined and subtle, despite the equally high alcohol content, and the layered richness of the malt is what your tastebuds will immediately be drawn to – it’s an explosion of honeyed fruit flavours.

I feel it’s a pity that this has to be diluted down before it is packaged and sold, but it’s perfectly understandable as the high AVB may be too much if you are not a whisky addict regular. Thankfully, the standard 15YO retains the nuances of its layered sweetness, but I’ll miss that explosive kick. I do wish that Glenfiddich will consider bottling small batches of these for sale though! (Glenfiddich’s tasting notes follow below)

Glenfiddich 15yrsold


Ex-bourbon cask
Nose Fresh apple and pear, subtle oakiness, light cinnamon and vanilla
Taste Crisp pear, loads of vanilla, creamy, with a touch of pepper and cane juice sweetness


Ex-sherry cask 
Nose Rich dark fruits, big oakiness, dried prunes and raisins, slight dry mustiness and a hint of chocolate
Taste Christmas cake, dried fruit, sherry and clove spice with a gentle chocolate note. Dry finish with a tannin bite

The new oak finish whiskies are unique to the 15YO – they aren’t used in the regular 12YO and 18YO.


New American oak cask finish
Nose Lots of wood, fresh sawdust, fresh ripe pear, strong Bourbon notes like coconut and vanilla, with light spice
Taste Pear coconut, vanilla, banana, brown sugar and a touch of ginger


Solera Vat (Undiluted and non chill filtered)
Nose Intriguingly complex aroma with sweet heather honey vanilla fudge combined with rich dark fruits
Taste Silky smooth, revealing layers of sherry oak, marzipan, cinnamon and ginger. Full bodied and bursting with flavour. Satisfying rich with lingering sweetness

The 15 YO is now, not the only Glenfiddich offering to be produced via a Solera process. The new Cask Collection, a Travel Retail exclusive that was introduced recently, is a range of three different styles of whiskies made in their own Solera Vats. The Select Cask features Bourbon, European, and Red Wine casks. The Reserve Cask consists only of Spanish Sherry casks. The Vintage Cask showcases a lightly peated spirit matured in a mixture of Bourbon and Spanish Sherry casks. 
glenfiddich cask collection




  1. […] Glenfiddich Regional Brand Ambassador, Matthew Fergusson-Stewart – whom we’ve had the pleasure of speaking to recently about WGS whiskies – and Regional Portfolio Ambassador Zachary Connor De Git will also be on hand at the event at various masterclasses to give attendees a deeper look into whisky and spirit appreciation (such as the vaunted Solera process that goes behind the making of the Glenfiddich Solera Reserve 15 Year Old). […]


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