Whisky experts say that 60-70% of a whisky’s overall flavour comes from the maturation process in casks. Most casks lying in Scottish warehouses are Ex-Bourbon cask from the United States and one might ask: Why are all these casks coming to Scotland?
In 1935 a Democratic Congressman for Arkansas, Wilbur Daigh Mills, helped to pass the US Federal Alcohol Administration Act, which set down the rules how bourbon has to be made. Mr. Mills lobbied by the timber industry, arranged it that a small but very important word found its way into the regulations. It was the word NEW. The regulations say “… stored at not more than 62.5% ABV in charred new oak containers”.
After prohibition the bourbon distilleries started more and more selling the whiskey in bottles – different to pre-prohibition time when a lot of whiskey was sold by cask. They had to get rid of all the empty casks that accumulated on their sites after bottling. Well, it is said that Scots have short arms but deep pockets so the Scottish distillers were more than willing to participate in the barrel abundance in the USA.
But alongside the ex-bourbon casks you can find a lot of other cask types in Scottish warehouses. By quantity, Sherry casks are the second kind of casks used to mature Whisky. In liquor stores you’ll find countless whisky bottles with the word Sherry on the labels.
Why Sherry Casks
Sherry Cask matured whisky is riding a global boom currently. Bloomy phrases on the labels of Whisky bottles create very personal perceptions about the casks that have been used for the whisky. The funny thing is that a lot of Whisky fans who are demanding a sherry maturation don’t even know what Sherry is. They persist on famous Sherry kinds, like Fino, Olorosso, Amontillado or PX, but never tasted them. Their main point is that the Whisky comes from a Sherry cask.
Sherry is a fortified wine that has to be produced in the Sherry Triangle – an area inside the cities Jerez de la Frontera, Sanlúcar de Barrameda and El Puerto de Santa Maria.
Fortified wine has a higher alcohol content then standard wine. This is reached by adding distilled spirits up to an ABV of 15-17%. Depending on the ABV the winemakers produce different styles of Sherry. As a rule of thumbs one can say:
The higher the ABV the sweeter the Sherry. This works because the yeast breaks down the sugar from the grapes and converts it into alcohol. If the ABV% doesn’t exceed 15.5% the yeast feels quite comfortable and a layer of yeast cells (flor) can be found on top of the wine. With the protection of this flor layer the wine is aging without oxidation and will stay clear. If the alcohol content is above 17% the yeast cannot survive and the wine oxidatizes and becomes dark.
The first Sherry Casks reached England in connection to the marriage of Catherine of Aragon to King Arthur of England in 1509. But it was Sir Francis Drake who brought the Sherry Casks to England during the Anglo-Spanish War. In 1587 he was sent to Cadiz and there he destroyed thirty-seven Spanish ships and stole 2,900 casks of Sherry. Drake delivered the casks to England and Sherry became the most popular drink in England. After the war a the prospering trade of Sherry between Spain and England began.
In the old days Sherry produced in Andalusia was transported to the UK by cask. Transportation to the wine the merchant took time – time to let the sherry seasoning the cask. The barrels where filled with Sherry that was produced for consumption.
The casks that are used for maturation of Sherry normally don’t leave the Sherry bodegas. Sherry matures in a so called Solera System and these casks are very precious. A good source for understanding Sherry can be found on the page about Consejo Regulador.
And even when the casks where not the casks that where used for the maturation of the wine from Jerez the casks in the old days where from very high quality. But in 1981 the export regulations for Sherry changed. Exporting Sherry in casks wasn’t allowed anymore and that impacted the supply of Sherry casks for the Scottish Distillers. Prices for Sherry casks where rising and a new industry was born:
Sherry Cask production for the Whisky Industry!
Sherry – Jerez de la Frontera
Inspired by a WhiskyCast episode from September 2016, my wish was born to visit a cooperage inside the Sherry-Triangle when I once should be in Andalusia.
Some impressions from the production at Antonio Páez Lobato
In June 2018 this wish became true. During our holiday in the south of Spain we had the chance to visit a couple of Sherry Bodegas and to try these delicious fortified wines. During our first tour at Gonzales Byass our guide explained that they don’t produce casks anymore. If they need new casks – and this isn’t very often – they buy them from local cooperages.
After a short email conversation with the management of Tonelería Antonio Páez an appointment was arranged to visit their production site.
Antonio Páez Lobato
Tonelería Antonio Páez is a family-run company from Jerez de la Frontera. In the 1940’s D. Antonio Páez started to sell his first barrels to wineries from Jerez and La Rioja. Today the annual production figures are about 20,000 Sherry cask of different types. An amount of about 17,000 Sherry Cask with a capacity of 500 liters is the major portion of the production.
Tonelería Antonio Páez has 47 employees and with only 5 in the administration you see that this is a real production plant.
The used wood is European (quercus robor and quercus petraea) or American oak (quercus alba) where the majority is the European oak with about 90-95%. The wood is purchased directly from sawmills in bigger quantities. The raw staves are delivered to the cooperage by truck and are just sawn and with a high wood moisture. Before using the raw sawn staves they are piled up on site and naturally air-dried for 15 to 18 month.
If the moisture content is below 16% the first real production step can start. The raw staves are planed on a semiautomatic planing machine and after that a trapezian shaped cross-section is created on a milling machine.
The exact shape of the staves is very important because when they are put together the barrels have to be watertight without any additional materials. The milling machine not only creates the desired cross-section but also a curved profile in order to achieve a bellied barrell shape at the end. Staves are produce with different widths and after the mechanical works the real craftsmanship begins. A cooper, assisted by a colleagues starts assembling the barrel. Stave after stave is arranged inside a production hoop. For a Sherry Butt (500l) about 33-35 staves are used. The smaller Hogsheads need 27-28 staves. What looks very easy is indeed a complicated work and needs a lot of experience and quite some craftsmen skills.
Unlike in Germany, where we have a dual apprenticeship system, there is no real training course in spain to become a cooper.
After all staves are in the right place some additional hoops are mounted to stabilize the labile cask structure. Now the wood takes a 30 minutes shower to be well prepared for the bending. The unfinished barrels, now having the geometry of truncated cones, are then moved over an open fire which is only fueled by oak wood. Many cooperage use gas burners in this production step – not so Tonelería Antonio Páez. At the beginning the fire is very small and the purpose is only to warm up the wood. Wood bends much better when it is warm and the wood cells become much softer when they have a higher moisture. So taking a shower and then over a small fire prepares the unfinished cask ideally.
After this warmup session the casks are well prepared for the bending process. Disposing a steel-cable-loop around the bottom of the cask a winch is doing the hard work (see video at 1:34). Steadily the winch is rolling up the steel-cable and reducing the bottom diameter of the cask. Meanwhile the cooper is adjusting the position of the staves to ensure the tightness of the barrel. Once the shape is finished the fire under the cask is reinforced (see video at 1:49)
With the inside surface of the casks exposed to these big flames a thin layer of charcoal is created. This charcoal affects the flavor and color of the spirit aged in the casks.
During the production special sets of hoops are used. They are changed 5 times in total before the final hoops are assembled.
After the charring process the bung hole is drilled and the cask is put on to a machine tool. This machine is shortening the cask, cutting a chamfer and creating a groove for the cask ends.
At Tonelería Antonio Páez no additional sealing material for mounting the top and bottom is required. The casks and the cask ends are produced so accurate that they just don’t need it.
After the mechanical machining the casks are sanded. All hoops, except the bottom and top hoop are removed and the outer surface is smoothed.
Now the cask is nearly finished. The final hoops are mounted on a machine called the Octopus – guess why :-)?
The last production step in the cooperage is the labeling. By laser beam the manufacturer logo, the production year and the customers’ name is burnt into the top.
To become a Sherry Cask one thing is missing. Right now we have a high quality virgin oak cask. But what the customers of Antonio Pàez mostly want is a Sherry cask. At Tonelería Antonio Páez the casks are filled at their sister company, Bodega Páez Morilla.
The Bodega is just a few kilometers from the cooperage. A stunning location outside Jerez de la Frontera. For seasoning the new Sherry casks Oloroso Sherry from the own winery is used. The casks are filled and put into the warehouse for two years.
After the 2 years the casks are emptied and the Sherry is pumped into large stainless steel containers with a capacity of 180.000 litres. To freshen up the Sherry they take 25% of the large tank and fill it up again with new wine. Doing this, the Sherry will never be overpowered by the new oak casks.
The obtained 25% of Sherry are going into their production of finest Sherry Vinegar.
So, if you ever are looking for high quality Sherry Casks I can highly recommend the cooperage Antonio Páez in Jerez de la Frontera.
Many thanks go to the lovely people at this great company who took their time to show me their business.