The Macallan Rare Cask, a ruby red blend with a heady aroma that blooms with raisin, spice, vanilla and hints of citrus, which translate onto the palate with a deep spiciness and raisiny sweetness, with lingering chocolate notes. Whisky maker Bob Dalgarno Whisky brought together a permutation of cask profiles, selecting just 16 cask profiles from the distillery’s hundreds of thousands for this premium release.  

Cask profiles? The factors at play include the type of oak (The Macallan uses American or Spanish), the size of the cask, how many times the cask has been reused, where it was made, how long the whisky has been aged, and so on. 

“Bob’s created a character that is different from the 18, and which going forward will vary from bottle to bottle,” says David Cox, director of fine & rare whiskies at Macallan owner, The Edrington Group. “We don’t put an age statement on it. You’ve got real flexibility to use whatever cask you want at whatever age you want, to come together to produce something which is interesting.

“The Rare Cask is a much more balanced whisky, slightly lighter in style in terms of nose and taste. You’ve got more obvious contribution from American oak, but it’s not American oak-dominated by any means. But some of the more Spanish driven ones are slightly more intense sweetness and spiciness and dry fruit. This has a fresher, softer feel from the American oak.” 

With so much of the whisky’s character attributed to oak, Cox delves deep to explain The Macallan’s history with its sherry casks: 

Tell us about the Rare Cask. 

Our newest expression from Macallan is made up from a really interesting selection of cask profiles: one might be Spanish oak, one American oak; one might be a first fill, one might be a second fill; one might first be filled with mosto wine, which is the first fermentation you get after the harvest, and then filled with dry Oloroso because the Spanish always feel that gives you the best maturation casks, some of them might have been filled directly with dry Oloroso.

Other variables include the cooperage the cask was made at; the bodega it came from; the cask size, which can be butts, puncheon [500L], Hogshead [225L] and so on. Age-wise, you’ve got casks from the 1980s all the way to 2002, which is the youngest. Our whisky maker Bob Dalgarno used only 256 physical casks to create the Rare Cask, out of nearly a quarter of a million. If you think about selecting from a thousand casks and only one, you have the idea of “rare casks” comes from. 

Why does Macallan use casks made of oak from Northern Spain oak and America? 

Fundamentally, the sherry cask, in both American and Spanish oak, is the backbone of our character, style and very DNA. The two is the species of the oak give off very different colours and flavours. It’s not the case for the whole industry; 95 per cent of Scotch whisky is matured in American white oak casks used by bourbon producers. It’s not a question of one being better than the other; it just gives you different character and style. Spanish or American oaks give off very different colours and flavours. 

We order staves of oak from Kentucky, USA—new oak that hasn’t been used for anything yet—and ship it to south of Spain to one of our cooperages. They make the casks up, give it to the sherry producers who put the sherry in it, we leave it for 18 months. 

We also go to the forests of northern Spain and buy oak for the same. The sawmill is in the north of Spain, the wood is air dried in the North, then in the south of Spain to reduce the humidity, the wetness of the wood, and then the casks made up exactly the same way, given to the sherry producers, stored for 18 months, then brought to Scotland. 

How many trees do you fell each year for making casks? 

If you’re asking if we’re denuding the forests of Spain and the US, I assure you we are not. The trees in northern Spain used to be felled at a very quick rate for warship production in England, as well as housing and railway sleepers. Oak isn’t needed as much for these uses today. Forest cover is growing back rapidly. Our harvesting makes pretty much zero imprint on it. 

Selected harvesting is a good thing, the foresters there will tell you. Because if you walk around, little oak saplings are just growing naturally, you trod on them everywhere you step. If you don’t clear individual trees, the canopies of trees interlace and overlap, as the trees are all rushing towards the light. And they end up growing very skinny and weak. But by clearing bits and letting light in, you tend to get healthier growth of trees. 

Depending on the tree, you might get one or four butts [500L casks] from one tree. We might take down 5,000-6,000 trees a year at the current rate in Spain. It might sound like a lot, but the forests are enormous in Galicia.  

These are probably 50- to 70-year-old trees. The older the tree, the more the cellulose, hemicellulose and lignin in the wood—the latter two are the ones that have most of the colour and taste compounds. So you tend to get more out of the wood if it’s older than if it’s younger. 

It’s really important that it’s all air dried, we don’t rush it. 

Typically it might be five years between when the tree is cut down to when we receive the wood in Scotland. So if a tree took 70 years to grow in the forest, add five years after it’s harvested, it’s filled with our spirit, and it goes into our warehouses for say 30 years, as some of our oldest casks are nearly 30 years old. 

So it could have been over 100 years from when that little acorn started growing in the forest, which will have an influence on your whisky. The journey in time and the scale is pretty amazing. 

How did this practice of using oak casks begin? 

When demand for whisky from Scotland started to grow in the late 19^th century, we needed to find a way to store and ship whisky. The most ready source of containers were sitting in places where sherry wine were bottled in the UK, which was then the biggest market for sherry in the world. All sherry was probably exported in bulk in these casks to London, Bristol or Edinburgh where the bottlers were. After the casks were emptied to bottle the sherry, they were just lying around, so we bought that. If there were casks for port, we bought that too—basically anything that was made of oak. 

And why use American oak? 

After WWII, there was an explosion of demand for Scottish whisky around the world. The problem was that while there was a surge in the production of whisky, there weren’t enough of sherry casks because prior to the World War, Spain had a terrible civil war that messed up supply of sherry. So where else could we get casks? There was only one other place where there was sufficient supply and that was the United States’s bourbon distilleries, because by law, they had to use only new charred American White Oak casks—you cannot refill the casks. So the whisky distilleries started buying more from these bourbon distilleries. 

How does that affect the whisky profile? 

American oak that has been seasoned with bourbon in it will give you a different character from a Spanish oak cask that’s had sherry in it. Macallan took a decision around the 1950s and ’60s, because Macallan spirit and sherry casks mature so well together, producing a rich, full flavoured character, that we wanted to continue buying from Spain. 

And what is the role of sherry? 

The sherry wine softens the structure of the wood and extracts the very harsh, sharp tannins from the wood; if you fill a new cask of oak, it would give a very bitter, dry, sawdust-y flavour. The sherry sucks some of that out of the wood. The sherry is then tipped out, and the casks are shipped to Scotland, ready to be filled. 

Wood is full of naturally occurring oils called vanillins. It is these oils that are drawn out of the cask by the spirit and over the period of maturation they add to the whisky’s flavour profile. So you get much softer taste compounds coming out of the structure of the wood and colour as well.

Does the type of sherry impact the whisky character? 

Macallan commissioned a bit of research in 1998-99 to look at the relative influences of “seasoning”—whether it was sherry or bourbon whiskey, or the spirit we produce at our distillery that comes off the still which is made from malted barley with yeast, and how much come from the oak casks. It was found that 10 per cent of the flavours come from sherry, and 60 per cent from the whiskey itself. 

The industry picked up on those numbers and uses it as a benchmark, but they’re not true for the industry because our sherry casks are particularly strong in the influence on maturing the whiskey. Another distillery might use much lighter styles and it’s unlikely that the spirit has 60 per cent influence.

What sherry do you use? 

We’ve picked our sherry partners based on scale: their ability to supply enough dry Oloroso sherry. The sherry industry has been depressed for quite a long time, but is recovering at the very top end. Gonzalez Byass is our biggest partner, and we’ve been using them for years and years. At their winery, they’ve got a huge warehouse in Las Copas and it’s absolutely breath-taking: you’ve stacks, floor to really high ceiling, of casks—our casks—full of sherry wine maturing. It’s a massive undertaking, really. We do use smaller bodegas, just as an insurance policy, to spread the producers so we’re not overly reliant on one producer. 

And what if one day, sherry falls completely out of favour? 

We’ll have to invest in vineyards! And sherry production! We have looked at it in the past, because we’re very conscious of the cycles of surpluses and losses. If it happened that we couldn’t get enough, we’ll certainly invest and do whatever we could to take direct control of that or in partnership with someone. 

Is there no alternative to sherry? 

In theory you could probably use other wines: brandy, port. Essentially it’s all doing the same thing, which is preparing the casks for us. It makes sense to use sherry because the cooperages are in Spain, they were part of the sherry business, use the wine in the region where you’ve got the cooperages—it’s partly pragmatic, partly historical. For that reason why it’s tradition we’ve always specified dry Oloroso sherries. If we use Fino, Manzanilla, Amontillado and Palo Cortado, would it make a difference? Probably not, particularly. But dry Oloroso suits us and we’ve always used it, so why change it if it’s working well for us?

But is there a chemical or physical way to prepare the casks other than having another alcohol in it? 

I couldn’t think of one, because it’s about seasoning the wood gently. If you try to rush it, by kiln drying instead of air-drying the wood, for example, you get different reactions taking place, which affect the whisky. 

Will the Rare Cask be produced annually? 

Well, we’re going to continue producing it, but whether it’ll be annually really depends on how fast it’s sold and consumed. 

It might be produced once a year, it could be more than once a year. It won’t be on a very frequent basis because we need to conserve all our stocks as well. If we start running down our old stocks too fast, it will have an impact on our other age statement whiskies. Hopefully it’ll be well received, and we’ll get into a rhythm of producing the next bottling. 

Going forward, it will vary from bottle to bottle. We don’t put an age statement on it, so Bob has real flexibility to use whatever cask he wants, at whatever age, to come together to produce something that is interesting. 

When Bob went about selecting the whiskies to blend for the Rare Cask, did he do it from his notes, or did he go from cask to cask, tasting them? 

Well, he’s got a team of two people. They draw samples from the wide range of casks he’s shortlisted based on wood type, seasoning, size, etc. They bring the samples back to the sample room and lay them out on the bench, and Bob will reduce them all—because, remember they all come out of the cask at different alcohol strengths—to 20 per cent alcohol by volume. And he notes all the samples, and by trial and error, he will put the blend together. And he might use more of one and less of another. It’s a constant playing around with it until he’s happy. 

Bob loves working on new whiskies. He has so much experience, it’s a bit like telling an experienced artist, create something completely new for us. This gives him a certain breath of fresh air, to look across the massive range of casks we have, all with different maturing characters, to play the tunes that he loves to do. He’s really passionate. I’ve spent hours with him till really late in the evening just nosing things, and I’m always amazed by what he produces.

Will the next iteration of Rare Cask have the same profile? 

No, it’s likely to be different, and that’s the great advantage of not having an age statement with a more narrowly defined character. Bob can play whatever tunes he wants, but whatever he does, he’s going to have to deliver something that’s worth the price that we’ll be charging in the marketplace, if not, why would you pay that? You’ve got to be able to justify it on a number of different planes: tell me about the cask makeup, how old are the casks, how rare are they. And at the end of the day, does it taste really good and am I getting value for my money? 

Hopefully people will, because we don’t make things that we don’t feel are beautiful whiskies. 

The Macallan Rare Cask

• Primary aromas and flavours derived from:
  Spanish oak sherry cask: chocolate orange, dried fruits and spices 
• •American oak sherry cask: sweet citrus, light spice, vanilla, light oak 
• •American oak bourbon barrels: sweet citrus, coconut, oaky