The Cathedral of the Cask

It is said that a mistake is only a mistake when you at least learn from it. When you continue to make that mistake, that is at the very least bad planning. It’s a Friday forenoon as I am writing this, so I suppose I really should know better. I am still going to call this a success as I finished the article on Friday as well, however only with 80 minutes to spare.

This week has seen a small burst of whisky activity, in which I have visited a distillery and cooperage, and it is the cooperage that is going to form the basis of this weekends article. I was wanting to do a bit of research into cask construction to give me a bit of a background for an article I am writing for something else and my visit to the Speyside Cooperage in Craigellachie did not disappoint.

When we think of whisky, the focus is always on the distillery and the casks are almost a foregone conclusion. Yet these should not be forgotten as they play a massive part in the formation of our dram in creating the colour and developing the taste from the distillate. Even then, all we think of is rows of casks sitting in a warehouse, but we don’t really think of what goes into making them. I can tell you now that it is more than you think and you would be surprised at actually how much. What’s even more surprising is how quickly it all happens.

The Speyside Cooperage sits just outside the village of Craigellachie, on the A941 between Dufftown and Craigellachie. It is a business that I pass regularly, but most often from the rear of the site, on the short cut between the A941 and the A95 to Aberlour and home. When passing the pyramids of casks (known as a Stow and is pronounced to rhyme with Now) I’ve always wondered how they process so many casks. On a snowy Monday afternoon I decided to pay a visit to the Cooperage.

Casks as far as the eye can see. I’m usually driving past at the other end of the yard on the way home. It was time to visit.

I chose the VIP tour, which allows access to the shop floor and the yard. This allows you to get as close as safely possible. The good thing about the VIP tours, especially out of season is the chances of getting a one on one tour is extremely high. While only mad dogs and Englishmen are said to go out in the midday sun, it is only perhaps the true whisky geek attired in appropriate amounts of Gore-Tex that will venture into Speyside to research barrels during a winter storm. Thus so it was the case that I got a solo tour with Rowan.

The tour starts with a very informative and well made video that is refreshingly full of easy to understand information and devoid of any corporate promotion, something that I note is more and more creeping into any whisky based tour. The video describes the type of wood used, how it is cut, and shows a basic overview into how a cask is made. After the video which lasts for approximately 15 minutes, you are then taken up the stairs to the viewing gallery where you can see most of the shop floor. Here you see the coopers in process repairing casks and what is instantly apparent is the speed that they work at. Because the coopers are paid at a piece-rate, it is in their best interests to have a high turnover of casks.

The shop floor (Tripadvisor / BartV495)

What is not appreciated is that the coopers are assisted by a a team known as the Labour Squad. These are the workers that assist the coopers by ensuring that there are casks ready to be worked on, by keeping the area around the benches clean, by making sure that they have supplies to repair casks. There are also apprentices at the far benches who serve their time over 4 years. There is quite a bit of interest when an apprenticeship comes up; apparently there were about 100 people applying for just one position.

The middle section in the photo above is where casks that are not repairable are put, and parts used from them to fix other casks. On the day that I visited, the workshop were repairing former wine casks, therefore they would all be similar in shape and height, but not every stave will fit every cask. You can see two casks in the middle section have their bands off and have some staves missing – these will be taken to repair other casks.

The cooperage can source or make a cask to order. The predominant wood in use is American Oak. This is for a couple of reasons. Firstly it is quite a dense oak, and the wood does not interact quite so strongly with the distillate as much. It also grows tall and straight with few knots, which means it is a lot easier to get a consistent wood quality that is less likely to split or leak. European oak tends to be a bit more porous. A typical American Oak will yield enough oak to manufacture 3 barrels. At the time I visited, no new whisky casks were being made and it was old wine casks that were being used. I never did find out what oak these were made of, but if it was European, it is most likely to be French Oak.

To ensure that the liquid stays in the cask, the staves are cut in what is called quarters. This means the stave is cut across the grain, and will stop the liquid in the cask leaking out.

From ‘Coopers and Coopering’ – Ken Kilby

So what happens when a cask comes in for repair?

The cooper will take the cask to his station, and give it a thorough examination. They are looking for cracks and splits in the wood or signs of other damage, such as a damaged metal band or hoop. There are usually 6 hoops in a cask – the top one is the chime, the 2nd one down one is the quarter and the one closest to the middle is known as the Bulge. This is repeated for the other end. The cooper will use a wire brush to knock off any debris and weathering on the outside to get a good look at the wood. If it requires repair, then the three hoops at one end are removed and the barrel inverted. Then he will slacken the top hoop and remove the other two, so he can open up the cask to remove the damaged staves.

Cask being reassembled. Two staves have been replaced. See the reeds just behind the cask for sealing the ends.

Once the staves are repaired, the cask is closed up, the bulge hoops are put back into position to start closing up the cask. The remaining hoops are placed on, but not into the final position. The cask ends are then put into position, and sealed around the edge with dried water reeds.

Depending on client requirements, if the barrel requires re-charring, the old char is removed and the charring process takes place once more. There are differing levels of char, which effectively blisters the wood to charcoal. This has a few uses – firstly it increases the surface area of the wood, to allow the spirit to interact more with the cask. The charcoal will also be a crude filter, and will help neutralise some of the less pleasant parts of the the distillate. It will also have an effect on the colour, taste and aroma of the final whisky.

Charring inside a cask at a Speyside Distillery

At the time of my visit, the coopers were working on old wine barrels, and this could be clearly seen by the staining on the insides of the casks. The casks were being charred at around 400C for about 100 seconds. The cooperage customer will ask for a particular charr level, and Rowan my guide informed me it is getting more usual to see higher temperatures for shorter times. Once the charr is complete, the cask is then subjected to jets of steam – this is to put some moisture back in the wood. The cask ends are charred separately in a facility outside, and are then returned to the cooper to make up a cask once more.

Charring in progress

It is thinking about the cask ends that I actually discovered something that I did not already know. Of course, the casks have no nails or glue holding them together, but I often wondered about how the cask ends are jointed together and this is where today continued to be a school day. Whisky casks generally have dowels holding them together. Several pieces of wood are dowelled each other then pressed together. Once pressed, the cask is then put on a lathe style machine to turn the cask end into a circular shape with the profile to enable it to seal correctly.

Cooper away to fit the casks end. Note the two replaced staves.

Wine casks are generally different, and what I saw was that the pieces of wood that form the end are pressed together using a tongue and groove effect. This makes the insertion of the cask end a little bit more tricky, but the coopers I watched assemble casks did it with ease.

Tongue and Groove of cask end section. Note how far the red wine has penetrated.

The assembled cask is then passed onto one of the labour team who use a machine to press on the two hoops at either end. This ensures a tight seal and that the ring is in precisely the correct position. Once this is done, all that remains is for the cask to be seal checked, which is done by putting some water into the cask and pressurised with air. Should a leak be detected, the cooper responsible has to repair the cask.

Should the cask pass, it is either put into a stow for storage, or it is transported immediately to the client. And here is where I learnt something new. For years, I have heard in distilleries that the casks are shipped broken down, however Rowan tells me that this is not necessarily true. It was calculated that it was more expensive to pay for a cooper to break down the cask in the US or Spain (Most casks used in Scotch whisky comes from the bourbon or sherry industries) then have them rebuild the cask in Scotland. So in effect, the cooperage is actually shipping air, as usually nothing is in the cask when it is shipped.

Some of the many stows of casks

There is a large collection of different casks on site. Everything from firkins (this was what the apprentices were working on) Quarter Casks, Barrels, Hogsheads, Port Pipes, Sherry Butts and Puncheons were present. In total there is around 200,000 casks on site at any one time. Wondering around the yard, the stows of barrels towered above us like a cathedral of casks. I had to wonder how much effort would be needed to knock the securing chocks out from the bottom and then to run from the tumbling casks. Thankfully that is not my job but images of Wylie Coyote getting buried in a in barrels after chasing Road Runner came to mind.

One question I had was how do they tell what each cask has held before or how many times it was used? The reason I asked was that each client has their own stows, yet the cask types (not sizes) were mixed. I thought it was something to do with the colour of the paint on the cask end, but the secret was a lot more mundane than that – it was usual to have the information on the paperwork when the cask arrived, and most casks now have a bar code or an alternative identifying mark.

1988 Jura. Cask a minimum of 32 years old.

I’ve got quite a lot of experience with cask ends, as I have been collecting these to use as decorative pieces for a local hotel bar, but nowadays these decorative cask ends are coming to an end in the larger distilleries at least. Many of them simply have a bar code on them. The distilleries are reluctant to allow these to be sold now, and many insist on the ends being painted over. Personally I think that this is a shame, as these marks tell a lot about the history of the cask. Remember that the wood it is made of is around 100 years old, then the cask itself can be as old as 40 – 60 years. I think it is nice to see all the dates that tell of whisky now probably long drunk.

At the end of the tour, we returned to the gallery where I am told that one of the coopers present is actually a world record holder. Davey Mckenzie had put a 190 litre barrel together in 3 minutes three seconds. Indeed, watching the guys repairing the wine casks, these were often repaired in around 10-15 minutes a piece, depending on how much work is needing done. It was now my turn to assemble a small cask, but I’m not going to embarrass myself only to reveal I didn’t manage – it really is a skill!

Finally it was time to finish the tour. It really was a great experience, and I think I spent 2 hours there, but it seemed a lot more. This was because you can get a lot of information and plenty of opportunity to ask questions in a short space of time. At the end of the tour, you get a tea or coffee, some shortbread, plus a bar towel and engraved Glencairn glass with the Cooperage logo. Oh, and a small nip of their own mystery single malt whisky bottled from a local distillery. I did tell my guide that I thought I knew what it was judging by the smell, but it is a secret. However, when I compared it to a sample of the whisky I thought it was, it was a very good match.

Don’t worry – I won’t tell.

I’d like to thank Rowan for her great tour. Whisky Geek Scotty was definitely on his best behaviour and didn’t get carried away. I’d also like to thank Andrew Russell, the General Manager of the Cooperage who took his time to answer a couple of questions I had to e-mail him in the writing of this blog post.

I can thoroughly recommend a visit to this cooperage, as it is one of the very few cooperages where you can see the cask being assembled from beginning to end. You can find out more by phoning the visitor centre on 01340 871108 or visiting

Yours in Spirits


Index of tastings here

Index of articles here

This is written as a hobby, and I appreciate your likes and shares, either on WordPress, or why not visit one of my other social media channels. Lets spread the whisky love!

Scotty’s Drams encourages responsible drinking. To find out the facts about drink, and where to find help if you need it visit by clicking on the link.

Photo Credits

View from Gallery – Tripadvisor / BartV495

All Other Photos – Author’s own

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