How to Repair a Whisky Cask: An Afternoon with a Cooper

Welcome back to another episode of the Enthusiast series here at the Whiskey Baron. I'm outside the Cooperage at the Tullibardine distillery here in the Highlands of Scotland. As you can see, there's a bunch of casks right in front of me. That's not what we're here about. We're here to go and see John, who's the cooper here, and understand what his job is all about and how they repair casks here at the distillery at Tullibardine. So follow me and let's find out. Right, so I'm here in the Cooperage with John. John's the lead cooper here at Tullibardine. John, you said you've been a cooper for quite some time, right? How long was it? I'll be about 46 years now. Wow, that's incredible. I mean, what a career. And how long here at Tullibardine? I've been here about nine years now. Cool. And I mean, this building here, the rest of the distillery, obviously it's got some history to it, but this is a little bit like stepping back in time when you look at all the tooling over here. It's such a manual, labour-intensive process, right? Can you tell us about some of the tools that you have to use when coopering? Most of the tools are just basically knives of some sort. We've got this an inch or an adze, as it's known, basically just for cutting wood. That's all that's for. We use those various tools, crumb knife. You'll see when I repair a cask what that's used for. Everything's a knife. We've got lots of them. These are head knives. I'll use these and show you how they're used when I'm repairing the cask. And yeah, we'll just, we'll get a cask going. I've got one ready to repair here, if you want to see that green done. Absolutely. So, I mean, in terms of what you're doing here, obviously it's a relatively small cooperage. What are you doing? Are you building casks? Are you repairing casks? What does your day look like? Well, basically we get the casks into the cooperage here. We don't build the casks here. We bring them into repair, make sure they're tight, ready for filling. If I need to go into the warehouse to fix something that's leaked, I'll go and do that. But most of the time I'm in here repairing casks. If there's a break in the wood in one of the staves or the end's broken, I'll replace that and get them all ready for filling, nice and tight. Cool. So, we've got a cask ready for repair, right? Uh-huh, yeah. So what have we got here? American oak hoggy? Ah, this is American oak bourbon cask. Yeah, okay. Yep, bourbon cask or barrel. I've cleaned the cask up a little bit here, just so I can find breaks. And I've found one here that I'm going to take out. I'm going to take this whole stave out because it's got a crack in it. Yeah. So, I mean, obviously some of these barrels get quite old, but how do you suddenly end up with a stave that's got a crack in it like this one? It's just me bending the wood when it's been made. It's under strain all the time, the wood. When I open it up, it will slightly straighten, so you can tell it's under pressure. And just over the years, it's just opened up a little and cracked. And the crack's got nice and dirty, so I can see it there. So, I mean, obviously, like you said, there's a clear crack in this. How many of these are you kind of seeing per week? How many repairs do you end up doing? Oh, it varies. It really varies on the size of the casks and the quality of the casks. Some of them can be really bad that come in. I can see five or six of these cracks in each cask. So, it takes a wee while longer to repair them. Ones like this, you can turn around quite quickly. So, in a good week, about 50 or 60 casks can be done in a week, hopefully. Cool. And obviously, it's not just barrels. We've got some bigger kind of sherry butts and the like over here as well. Yep, we've got a sherry cask here. This is an Oloroso sherry cask. We get these in quite a lot. They're European oak. They're not like the American oak. Slightly lighter oak, quicker growing. Tends to be a bit weaker, so the cracks tend to be bigger in these when they happen around the pitch. There's none in this one, luckily, at the moment, but with the wood being faster growing, it's weaker. So, when a crack does open up, it opens up quite substantially, and they tend to leak more. So, we've got European oak cask here. This is agie size, and behind it here, the bigger thing, that's a Punchen. Again, European oak, and that'll hold about 500 litres. Yep. Whereas this will be about 250. The bourbon cask, about 200. And so, obviously, we're going to replace the stave here, and when it comes to, like, how do you get the extra wood? Do you just look at casks you're no longer using, break them down, keep a supply of staves? Are you buying staves in? Like, how do you get the wood for the repairs? Yeah, well, when we get a load of casks in to do, we'll usually pick out the biggest ones, the tallest ones. We'll just break them down. We've got a couple here that are open up already. We call those shifters, and we'll take staves out of these and use them as we're going along repairing casks. So, there'll always be two or three disappeared for a load that have been used for spare parts, really. Cool. So, the one thing that you don't do here is kind of re-firing, re-charring the casks, right? No, don't do that. But I'm presuming you don't always need to do that, right? You can re-couper a cask after it's been filled and then put it back into the warehouse straight away. Yeah, definitely, definitely. It depends on how long it's been full of husky, really. If a cask's been in a warehouse for 15 or 20 years, you're going to want to re-fire it, re-char it. If it's just been filled for maybe a year, maybe even less, some of them, some of our finishes, we'll empty the cask and we'll just make sure it's tight and we'll re-fill it. Yeah. So, when you say make sure it's tight, do you have a pressure test you do on it? How are you checking it? Yeah. Once it's repaired, we'll get water in it and we'll roll it around, make sure it's tight. We can put some pressure on it and we'll just look for leaks. Yeah. Hopefully, there's none. And then off it goes back into the warehouse? Yes. I mean, obviously, you've got a bunch of staves over here as well. So, I mean, yesterday, I was in the warehouse and we saw some barrels being disgorged. I think it was going to be for the 15-year-old. It always fascinates me when you see the troughs, just how much of the inside of the barrel you get. And occasionally, you have a dram straight from the cask and there's a little bit of char and stuff floating around with it. But I guess when you see these staves, you start to understand a little bit why some of that ends up in the cask because it's pretty delicate, some of the stuff in here, in terms of the way they've been charred in the past. So, you've obviously got different levels of char types, like medium, people talking even about crocodile chars and all kinds, right? Do you need, when you're replacing a stave, to worry about the char level from your stock or if it's just kind of one stave in a barrel, it's not going to make too much difference? Yeah, you don't worry too much about the char level as long as you stick to the same type of cask with the wood you're putting in. If you're repairing a bourbon cask, use bourbon staves. If you're repairing a wine cask, use wine staves. The levels of char, you don't really worry about. This is quite a mild char, you get medium chars and heavy chars as well. This one's quite a light char that we have here. I'll be using wood for this cask or the one behind it when I'm repairing the bourbon cask that I'm doing in a moment. Great. Obviously, you've got two different sizes of stave here as well. You're also having to fit them to the barrel by slicing off bits of wood at the same time as well. Yeah, yeah, definitely. We'll put a line around the cask when we open it up so we're getting wood in a row because the joints are never exactly the same. It's all done by eye, it's not done by machine. We can choose which staves we need. If we've got a wide stave, we'll try and replace it with a wider stave. Sometimes we need to use two smaller staves just to make up the space. Everything will be cut to size. Cool. All right. Should we go repair a cask? Excellent idea. Couldn't have said that better. So, obviously, we've tried a little bit about this cask already. So, you know, we've started this one prepared earlier for us. You can obviously see from the marks, some of the boots have already come off around this one, maybe a little bit. So, Abby, a tip for the rest of the cask, what do you need to do? I'm going to start at this end and I'm going to take this end out. Okay. All right, let's go for it. So, obviously, a little bit of liquid. Yeah, some whisky there. A little bit of whisky we've got on the corner. Stand it up. Smells lovely. That does smell really good, actually. You can see where it's been sealed, where it reads. With the reeds, yeah. Yep, round about it, round about what we call the crows, this groove here. Yeah. That the end sits in. It seems amazing that after kind of hundreds of years of the whisky industry being around, that no one's found anything better than some reeds that you've got over there to help seal the inside of the cask. Yeah. So, we have a quick inspection of the inside and everything seems to be fine. The main thing you look for on the inside is round about where the bunghole is. Yeah. And it seems fine in there. So, what we'll do is we'll stand it up, pop it over here and we'll take these other hoops off. We'll loosen one, we'll loosen the end hoop and we'll get rid of this one, which is called the quarter hoop. Yep. Then we'll find our stave that's marked to come out. There we go. That's the one. We'll just loosen this off a bit more. It's the last hoop you just loosen rather than take off the inside thing. If you took this hoop off, everything would just collapse. So, that's a nice and loose. I'll just knock it out now. And there we have the stave ready to be replaced. Yeah. It's interesting, isn't it? When you look at the stave and actually look at the thickness of it, what's about an inch thick or so, right? To see that crack on the outside, it's easy to forget that wood is a porous material, right? And because you've got a crack on the outside, stuff is going to start coming out. Yeah. It's only going to get worse. You can see the cracks coming down there. Yeah. That quarter of the way. And it's quite deep, yeah. It's going to get worse over time. So, we'll have to replace it. Cool. All right. Let's do it. So, when we're selecting the new staves to go in, what I'll do is I'll try and find one that's slightly wider. Right. Slightly wider because then you can shave a bit off of it because obviously you can't add to a piece of wood, I'm guessing. Yes, exactly. So, this one is a bit wider. Okay. That's a fair bit wider. A centimeter or so, yeah. We're going to try and match up the grooves on each end. So, we'll just see if it'll match up. It doesn't quite. So, I'm going to have to work it a little bit to make it match up. Cool. All right. So, over to the tools. Old one, I'll prop it up in place. I'm just going to take a little round on each side, each joint. Yeah. I'll just do that on the surface plane. So, obviously, you've planed off a little bit of the wood and now you've got kind of much fresher wood on the side. A nice joint on it. Nice joint. But presumably, again, because it's not really the inside of the cast, that doesn't matter. That's kind of now fresh compared to the char on the inside, right? It's not touching the whisky, right? And you said that this, you know, the stave's still a little bit bigger than it was previously, right? So, what are you going to do about it? Well, I'm going to put the stave in now. So, it's going to fit in anyway? It will be going in the smaller hole. Sometimes, when you make the cast, you make the ends a bit tight for the cast. Yeah. So, we're putting about a centimeter extra wood in here. It lifts the hoops slightly. Yeah. And it takes the pressure off the end because the ends can warp. Well, you can see this one has like warped a little bit here, hasn't it? Yeah. So, but this is still tight and it doesn't need replacing. That doesn't need replacing. That's fine. We're putting the extra wood in. It won't leak. When we're tightening the hoops down, it will crush the wood in. So, it'll take up any loose areas in the joints. Yeah. So, it helps the cast a little, putting a little more wood in when you're repairing. Okay? Cool. Right, we'll pop some hoops back on now. Cool. The top hoop off. These are holding it together enough then that you've got the opportunity to play around with that a little bit. Yes, I can work on this now. What I'm going to do first is I'm going to get one of these reeds. Yep. Called flags in the trade. I'm just going to pop it in round about the end here. Yeah. Pop it into the crow's. This will help seal in it. Then we'll pop the end hoop on nice and tight. Perfect. And knock everything into place. It's pretty physical work, right? It is, yes. I approach DIY at home and I get told that. I get told I'm doing it the wrong way. See, I think it's... Better brute force. That's all it needs. You have to persuade the wood into place. Yeah. When we're working on the cask, we always keep the stave with the bong facing the bench so we know where we are on the cask. And the wood we put in is this stave. Yep. And it looks like it's lining up nicely. So I'll pop another hoop on it. This is what we call a truss hoop. I was going to say, this looks bigger and more heavy-duty than your average hoop. This is a truss hoop. This just helps the cask pull into shape easier. Yeah. Then we'll pop it down. We'll persuade it into place. Persuade it into place. Okay, off we go. To see if the staves are even. Yeah. Right about the pitch. And there's a few here. They need a little tap to bring them out. Yeah, I can see. Yeah, you've got that. So I'll just hit it with the hammer inside. Just to bring them out nice and flush. I'll do that all the way around. Everything's been hammered and sawn. And this is the hoops from the other end. We'll pop on the quarter hoop. It goes up here. Now the hoops. That's a quarter hoop. You get the end hoop. Then you get a bond hoop or pitch hoop. So we'll pop this one on. Then we'll work the stave just to make sure everything's perfect. So it's done its job. So it can come off. And we'll pop on the bulge hoop. Cool. The staves that we've put in. If we have a look at this. You can see it's lining up pretty well. The crow's there. Yep. What I'll do is I'll just trim the top down to the right level. This is for cutting the groove where the end goes. As you can see there, there's some little knives there. Two that cut a groove and the other one works like a chisel. Just takes the wood out. So this is like a special, it's like special cask making tool. Yes. Yeah, definitely. You won't see this tool in any other trades. It's nice and even now, the crow's. So what I'll do is I'll take off the quarter hoop and I'll pop the end on. Yep. Cleaning off the like the old reeds from the cask end. Obviously you're doing cutting then. A little bit of sawdust and stuff now that's kind of sat in the cask. Does that need to get cleaned out? No, that'll be fine. More wood the better as to the flavour of the whisky. Plus the whisky will be filtered when it comes out of the cask. So if there's only a little, that's fine. Cool. All right. Putting in the cask end seems like that requires a slightly different, more gentle approach than some of the rest of the work. Definitely, definitely. Again, we'll seal the end with these reeds. Pop the end tube on. We tend to keep the rivets and the hoops. Yeah. We tend to keep all those in line with the bung, Steve. Okay. It's handy for when you're in a warehouse, especially if it's dark and you've got a cask in the rack and you're trying to find where the bung is but it's quite dark or the cask's high up and you can't see it. You can feel around the cask and feel where the rivets are in the hoop. So it helps you when you're storing the cask in the warehouse. Yeah, cool. That's clever. Just clean up the flags a little and we'll give it a final tightening. One of the machines that makes life a lot easier instead of going around this with a hammer and driver tightening away. Is the automatic hoop driver that I have here. We'll pop the cask in that and we'll get the hoops tight. Okay, let's do it. It's like a very specialised piece of machinery for the industry, I don't know if anyone else has something. Yes, you get it a lot in the wine industry and the whiskey industry. Very specialised, takes a lot of work out of Cooper's job. Yeah. As you can see, it's a physical job and this helps tremendously. Absolutely. There we have it, one fully repaired cask ready to go. I mean, look, the cask's looking great now. I've certainly learned a lot. Hopefully you guys at home have as well. John, just want to say thank you so much for taking us through the process today. Really appreciate it. No problem. Thank you for coming. Yeah, cheers. And guys at home, thank you so much for watching and we'll see you again on another episode very soon.