Recently, I was lucky enough to visit one of Scotland’s oldest working distilleries, the Annandale Distillery, in the gorgeous Scottish Lowlands. 

The distillery, which was founded back in 1836, produces exceptional malts, both peated and unpeated. I recently reviewed a few drams from their Man O’Words and Man O’Sword range. If you’ve not yet, make sure you check out both the blog, and the whisky, as I’m sure you’ll enjoy both in equal measure. 

While there, as always, I took a quick stroll through the woodland next to the distillery and admired their hugely impressive selection of ‘wet casks’ stacked up neatly in the woods. When I mentioned this to a friend a short while later, he looked at me puzzled, and asked ‘what’s a wet cask?’

I sometimes forget that not everybody is self-proclaimed whisky guru, and often the terminology is lost on some people. So, today, I thought I’d clear up the mystery and look at wet casks in whisky making, why they’re important, and what they’re all about. 

What are Wet Casks?

If you ever get chatting to somebody working in the whisky biz, you may hear them talking about wet casks. That’s all well and good if you’re a whisky expert, but what if you’re just a casual single malt drinker, slowly discovering the fantastic world of Scotch? Well, that’s where the GreatDrams blog comes in so useful. 

Not only do I want to sell you amazing whisky for even more amazing prices (shameless plug alert) but I also want to help you learn as much about this amazing spirit as possible. Whisky is so much more than just a drink. For me, and many others, it’s an entire world and what’s even more exciting is the fact that I keep discovering brand-new things about it, including the different types of casks used in its production. 

So, is a wet cask simply an old whisky barrel that’s been left to soak in the UK rain for months on end? Absolutely not! That would be a travesty. No, instead, wet casks are much more than that. 

Put very simply, a wet cask in this context is one which has recently held a different liquid such as wine, sherry, port, bourbon, or anything similar. In some cases, the wet casks may even have a few dregs of liquid left in them, which quickly evaporates before the whisky is transferred into them.

These barrels are sourced from various distilleries, vineyards, and other similar businesses and after a safety inspection, including the contents, they can then be sold to other distilleries, independent bottlers, and other creative individuals. 

Once sourced, the suppliers will inspect several casks from each batch, and test for water tightness and any signs of leakage. They’ll also inspect the casks themselves, to make sure they’re in good condition and free of any signs of damage, mould, or other nastiness that you wouldn’t want anywhere near your whisky. 

Any liquid inside will also be examined, as samples will be taken and tested to ensure that it is what it’s supposed to be and that it’s safe. If a client had specifically requested red wine casks, they’d be annoyed if they were actually supplied with sherry casks instead. Once the sample passes the necessary safety checks and inspections, the casks are then ready to be sold on. 

As for the barrels that don’t make the cut, well, they don’t go to waste either. They can be sold to be used as furniture or even broken down into wood chunks for smoking food. As I’ve recently turned 40, I’ve naturally done what all men my age do, and have started to dabble in smoking my own meat and fish. I have to say that cold-smoked salmon, smoked with chunks of old whisky barrels is exceptional. 

See? Nothing gets wasted and we’re all about sustainability here at GreatDrams. 

Why Are Wet Casks Important?

As you probably know, the majority of a whisky’s nose, flavour, appearance, and general character is taken on during its maturation period. Legally, Scotch whisky has to be aged in a suitable barrel for at least three years before it can be sold as Scotch. 

The majority of Scotch distilled over here is first aged in ex-bourbon casks. It may then be transferred into a different cask to take on different notes and flavours. Bourbon casks are used at the start, mainly due to the fact that they’re more affordable and plentiful, as American distilleries can only use them once for legal reasons. Once they’ve been used to produce bourbon, they’re then sold in bulk, at a discount to distilleries all over the world. 

As these casks have previously held bourbon, they help to impart sweet caramel bourbon and oaky vanilla notes into the Scotch. If you want to produce a so-called sherry bomb whisky however (a whisky with strong sherry notes) you’d almost certainly age it in a wet cask which had recently held sherry. Usually, Pedro Ximenez (PX) or Oloroso sherry casks are used in the whisky industry, though others may also be used. 

Put simply, if you age a whisky in a wet cask, chances are that the whisky will take on some of the notes, flavours, and characteristics of the liquid the cask previously held, along with plenty of others. This is down the fact that the majority of casks used in whisky maturation are made from oak, which can be very porous. Oak doesn’t only absorb and soak up some of the liquid stored within, but it will also help to impart these notes and flavours into the whisky once it goes inside. 

The great thing about this is that, not only does it help give the whisky an amazing flavour, but as the oak swells, it also helps keep the barrels watertight. 

If the casks were dry – either brand-new, or so-old that all of the previously stored liquid has completely evaporated, the whisky would struggle to take on any flavours, other than from the wood itself. Now, I keep mentioning old oak wisdom, and how important oak is in whisky maturation, so please don’t think that dry casks don’t have their place in the world of Scotch, because they most certainly do. Any whisky aged in dry casks, however, will likely take longer to take on more colour and flavour, and will have more prominent oak notes to it. This is no bad thing as there are plenty of exceptional drams out there which are especially heavy on the oak. 

So, that, my friends, is why wet casks are so important in whisky production, and it’s one of the main reasons why I was drawn to them while at Annandale last month. 

If you’d like to learn more about your favourite whiskies, or simply treat yourself to a dram or two in the process, be sure to head on over to GreatDrams.com and take a look at what we have to offer. 

With an impressive selection of limited-edition, rare, and award-winning whisky, as well as heaps of whisky info on our blog, it’s the perfect spot for any whisky lovers out there.