Single cask whisky offers something truly special—a one-of-a-kind experience in every bottle. Unlike blended whiskies, these come from a single barrel, giving each bottle its own unique character and making them incredibly limited. As Whisky & Tasting Panel Coordinator, I’ve spent years with the Scotch Malt Whisky Society, and exploring these rare expressions, and the individuality of each cask, never fails to amaze me.
In this article, I’ll dive into what makes single cask whisky so distinctive, how it’s produced, and why it stands apart from other whiskies. From cask strength flavors to the impact of maturation, we’ll explore the craftsmanship that goes into each bottle.
Signup now to make sure you don't miss out on the latest whiskey news and deals.
By Signing up, you accept and agree to our Terms of Services and you acknowledge our Privacy Statement. The Whiskey Wash is protected by reCAPTCHA, and the Google Privacy Policy and Terms of Service apply.
What Is Single Cask Whisky?
When we talk about a single cask whisky, we describe a whisky from one distillery that has spent its entire maturation in one type of cask. Generally, this means that the whisky you get is from one cask only and therefore in phenomenally limited quantity.
The largest legal cask for scotch whisky holds just under 700 liters. If filled at the industry standard of 63.5% ABV with no losses, it could yield up to 1,000 bottles at cask strength. If the whisky is then diluted to 48% ABV, you could hope for a maximum of 1,322 bottles.
Most casks in the scotch whisky industry can hold a maximum of 200 to 500 liters. On average, 2% of the alcohol in the cask is “lost to the angels” every year, so you get the point. No two casks are the same and bottles filled from each of them are in incredibly short supply.
How Is Single Cask Whisky Different From Other Whiskies?
Single cask whisky distinguishes itself from other single malts, blended malts, and blended whiskies in that it can never be blended or consolidated. Not even with a whisky from the same distillery, distilled on the same day and matured in the same type of cask.
Once the last bottle of a single cask is cracked open and enjoyed, it is water (of life) under the bridge. That specific expression will never be seen again. Though it may sound sad, in a way, this is quite the opposite and a gateway to perpetually new and unique experiences.
Single casks are much like a snapshot of one specific day, or week, at one specific distillery. Just as you can never take the exact same picture twice, you can’t fill the exact same cask twice, no matter how much you would like to. The history of the Scotch Malt Whisky Society is filled with examples of casks filled on the same day and bottled in close succession that showcase a strong family resemblance but also striking differences. It’s fascinating and eye-opening.
What Does ‘Cask Strength’ Mean?
Cask strength does what it says on the tin, really. It means the whisky is as it comes out of the cask for its alcoholic strength. Another way to put it is ‘undiluted’, at least from the cask.
While it is seen on occasion, it is not generally common practice to cask spirit as it comes out of the still. It is first collected in the spirit receiver and the strength is brought down to somewhere around 63.5% (for scotch whisky anyway) before being poured into casks.
While this step is not a legal requirement and may be deliberately ignored for stocks meant to age a long time, it is a useful process to obtain a more consistent whisky down the line. Moreover, there is a general perception that filling at too high a strength can be detrimental to the cask and its longevity.
For whisky drinkers though, what this means is that they are offered an unadulterated expression of whisky which they may choose to dilute to the level that pleases them most on any given day. Drinkers can also sip it neat to take in the powerful and robust palate that these expressions offer.
Just imagine the concentrated cereally, floral, and fruity notes of some Speyside or Highlands whiskies in bourbon casks, or the smoldering, treacly, and smoky depth of a heavily peated Islay dram in first fill Spanish oak sherry. Whatever you choose, cask strength whisky will offer an experience of superlative flavor intensity.
Is Single Cask Whisky Better Than Blended Whisky?
That’s a question that keeps coming back. But in our books, it’s apples and oranges.
These two whisky types exist for very different reasons. On the one and, single casks were barely ever seen before the days of the Society and, as I was saying, they capture the character of a distillery on one particular day in one particular cask. They end up tasting the way they do because of raw materials, equipment, processes, and a fair bit of hope that the cask will do its job as expected. But each cask is different, each tree they are made of grows as nature intended, so there can never be a perfect consistency from one cask to the next.
Most blended whiskies on the other hand are made to fit into a specific flavor profile consistently, using sometimes eyewatering numbers of casks. Blended whiskies (we are not talking about blended malts here) also use grain whisky which is a lot less expensive to make and is much more neutral than malt in its flavors.
So, blends certainly have their advantages and are quite flexible. They can range from entry level inexpensive fodder for your highballs and mixers to highly luxurious and pricy antique concoctions to sip and savour on their own. Nowadays, we also see more independent blended whiskies and blended malts appearing that sit somewhere in between those two extremes.
In a nutshell, the blended scotch whisky category has so many different incarnations that it is impossible to make a judgment on how it compares to single casks. And again, we should probably refrain from comparing things that are so radically different in nature. Just go forth and explore without preconceptions, you only have your taste buds to answer to.
How Do You Choose A Good Whisky To Bottle From A Single Cask?
There are no shortcuts. Experience tells us what might be ready for us to consider, but the final decision belongs to our tasting panel. If they deem something is not ready or not as good as it should be, then it will not be bottled. Ultimately, while it’s good fun to have interesting and quirky packaging, the real value of whisky is in its flavors.
So, know yourself and the flavors you usually enjoy, and read tasting notes before you order or purchase a bottle (they are meant to be fanciful but very informative, just take a step back and try to imagine). Or even better, taste it if you have the opportunity to do so. After all flavor preference is eminently personal and some will relish a balanced dram with elegance and complexity, some will prize juicy fruitiness while others still will only swear by the coastal punch of peat smoke of some Hebridean and Orcadian malts.
But it’s not all about single casks.
We have developed well-recognized expertise in additional maturation where we put a whisky into a different cask and is therefore by the strictest definition no longer single cask whiskies (the whisky having been moved from its original cask into a new one). No effort is spared to use only high-quality casks and then a long monitoring process ensues, that lasts for a minimum of – but almost always much more than two years. I still believe that these casks showcase that snapshot of a day in a distillery’s history.
But don’t take it from me, the Society has been trawling in no less than 163 awards for these extra-matured whiskies since 2018.
Where Can I Buy Single Cask Whisky?
www.smws.com or www.smwsa.com if you are in the USA. If you find yourself in Edinburgh, pay us a visit at our Kaleidoscope bar at 28 Queen Street, you will have the opportunity to taste a wide range of single casks and if these are pleasing to you, we’ll be glad to welcome you as a member and give you access to a wide range of single casks and single malts as well as curiosities for you to discover and enjoy.
You can also find us at many whisky festivals around the world, and we organize tastings in many countries around the world that are also accessible to non-members if you’d like to sample some great whiskies and meet other whisky fans.
How Should I Store My Whisky?
Store the bottle standing on a shelf and keep it away from sunlight at reasonably cool temperatures. If you’re planning on keeping a bottle for a while, or even decades, wrap the top and neck of the bottle with parafilm to avoid residual evaporation.
Once opened, don’t feel like you have to drink your bottle really fast, it’s not going to go off anytime soon especially if stored adequately.
There are many ways to store opened whiskies, and I’m sure there are many fans out there who will tell you that they have found the optimal way to store open whiskies., and that’s fine. I’m just content to keep those on my shelves in a nice and cool environment away from sunlight. So, take your time, open one, two three, or as many bottles as you fancy, you can always go back to the previous one. And don’t forget to share with your friends, it’ll keep your shelves tidier!
What Are The Different Types of Casks Used For Single Cask Whisky?
Any cask that is legally allowed in the production of scotch whisky could end up as a single cask if the conditions are right and the quality is there. For a very long time, the American oak bourbon cask has dominated the landscape of single cask whiskies, and whiskies in general. It used to be quite affordable, trustworthy, and great quality wood providing vanilla, coconut, and honeyed flavors.
But in recent years the balance has started to shift again towards wine and particularly sherry casks. Since 2015, the Society has spared no effort sourcing the best possible sherry casks, but since 2019 it has also taken a proactive approach to commissioning casks coopered to our standards and used for sherry production in fantastic sherry bodegas before being sent back to us for our whiskies to mature in fresh sherry casks.
While we have so far predominantly released extra-matured whiskies from these casks. There are also numerous whiskies matured in such casks that have started coming through and will continue to do so for the foreseeable future.
How Does The Cask Influence The Flavor Of Whisky?
Many try to quantify how much of the flavor comes from the cask and how much from the spirit, but in my books, trying to put numbers on this is a fool’s errand. It all depends on the qualities of a spirit and on the individual cask.
A heavy, oily, and peated distillate will easily beat most casks into submission, while some lighter floral and un-peated whiskies might find balance when married to a second-fill or re-fill cask over a longer time. Even some un-peated distillates from places like SMWS distillery No. 44 would easily overpower some quite active sherry casks.
The main thing when considering casks is quality. We ensure that we have the highest possible quality of casks by working with select cooperages in the UK, Spain, France, the USA as well as sherry bodegas, working on our own cask seasoning programme as well as creating casks that are not so much seasoned as used to create real, high-quality sherry.
What Is The Difference Between An Independent Bottling & A Distillery Bottling Of A Single Cask Whisky?
If you are comparing like for like, single cask to single cask, then I’d say very little. It just depends on how an independent bottler selects their stock for bottling. Is the independent bottling put into glass because it was good or just because it was there to be bottled? A distiller has thousands of casks of their own makes to choose from, so you could think that they have the upper hand, but sampling thousands of casks is not practical, and it takes a while.
So, while distillers certainly have numbers on their side, they are likely looking for whiskies that epitomize their vision of their distillery character whether they go for a common type of cask or go a bit more experimental. This is a good thing.
For us, acquiring casks is a lifelong challenge and vital to our future. So, whatever we do we aim at casting each whisky in the best possible light. We do that by putting quality first and expressing that quality in as wide an array of ages and flavors as possible.
Trending Stories
In many cases we try to explore cask types not traditionally seen for a make or we get more experimental, leaving the realm of single casks. Another example of fun things we do with whiskies is combining two casks, sometimes similar, sometimes very different, into one single malt expression, or splitting a large cask into two different smaller ones, taking both halves in different flavor directions entirely.
To become a member of The Scotch Malt Whisky Society, visit www.smws.com or www.smwsa.com if you are in the USA
Latest News