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The importance of maturation.

Updated: Aug 15, 2022

Just as so many discoveries happened by accident, so too was wood ageing. During the Late Middle Ages, when there was already eager distillation in Europe, wooden barrels were simply used as a means of transport to transport the distilled liquid. After a few weeks at sea, it was established on arrival that the liquid had turned browner due to contact with the wood. This was not taken into account and most spirits were quickly consumed. There was therefore no question of commercial maturation in wood.

Uitladen van vaten in de Nederlanden ca. 17e eeuw

Unloading of barrels in the Lowlands (18th century).

Until the moment that some barrels were forgotten and ended up after a long time. When the wood-aged spirits were tasted, it was found to have been improved by the long time spent in the barrel. This was discovered in 1549 in France in the Charente region, where Cognac was distilled. There, merchants from the Netherlands distilled the sour, fruity, but also low-alcohol, white wines to give them more alcohol and thus more aging potential. The long sea journeys to the north were disastrous for the untreated wine and it had already become sour before arrival. At first these wines were distilled into “brandewijn” on arrival in the Netherlands (ed.: “brandy” is derived from this), but after a while it seemed more economical to do this at the place of shipment in France itself. This had several advantages: the distillate took up less loading space, had an unlimited shelf life and could be diluted to drinking strength at the destination. After prolonged maturation in the wooden barrels, consumers found their brandy more complex and of higher quality. Today many distillates are aged for long periods in wooden barrels of various types. Barrels are used that are new, which means that no other drink has ever been used, and barrels are used that have already been filled with another drink. In our distillery we also have barrels of different sizes, types and origins. The majority here consists of two types of casks: bourbon casks and sherry oloros casks. Each of them contributes its own character to the drinks that are matured in our distillery. The added value of years of aging in these barrels is phenomenal for the spirit in the barrel. The dance between the liquid and the countless aromas in the barrel is one that must be able to take place undisturbed and that requires patience to achieve beautiful results. Only then can a cask give the best of itself and give an extra dimension of character to the distillate.

Bourbon casks

These barrels are of great importance to Van der Schueren. Often they serve as the first base for different spirits to lie on for the longest time. These are always about 200 liters in size and we buy them through Scotland, the largest base for bourbon casks as most of the Scotch whiskey disappears on this for a few years.

Since the American law for making whiskey prescribes that it may only be aged in new oak barrels, it is often shipped to Scotland after bourbon has matured. Contrary to American law, Scottish law provides that Scotch whiskey may not mature in new barrels or in barrels that have already been used for maturing another drink (eg bourbon). Most bourbon casks with us are from one specific American distillery, namely Buffalo Trace Distillery. We selected the barrels from this distillery years ago as the ideal match with our own distillates. The aromas of vanilla, caramel, banana and coconut that are rich in the barrels, mix masterfully over the years with the spirits that go into it. The barrels made of American oak, or White Oak, are first filled with American whiskey, or bourbon, for several years. Once emptied, these are sold to other distilleries. The preceding bourbon is therefore essential and partly determines the complex taste with the wood.

Sherry oloroso casks

Absolute tastemakers and typical of some of our drinks! Sherry casks are mainly known by the British and the Flemish. In the 16th century, the export of sherry was mainly destined for Great Britain, but especially the Flemings knew how to taste it.

When exports boomed, it was cheaper for the Spaniards to simply transport the wine in the barrel instead of bottling first.

Export of sherry casks on the docks of El Puerto de Santa Maria (1880's).

Once the wine was out of the barrel, it was left without purpose. Given Scottish law, Scottish distilleries used these casks to age their whiskey. And with success. Today, the best whiskies are often aged on oloroso cask or "finished" on it. Finishing means that the spirit only spends the last few months in a particular cask to subtly get the aromas of that cask. When sherry began to be bottled at its place of origin, the barrels also suddenly stayed behind in Spain, causing prices to rise. Good sherry casks today are expensive casks compared to other casks.

The crossed O is the sign of oloroso in cask

But not only for us, but also for many other distillers, the price is more than worth it. In our barrel room, our sherry casks enrich our distillates with aromas of dried fruit, almond, nuts and a slight salty touch from the previously oxidized sherry that remains in the barrel. The latter is important as there are different styles of sherry. We opt for oloros vats because the sherry that matures in it first is deliberately matured oxidatively and therefore gives off more nut flavors afterwards. Delicious and desirable! We can buy our Oloro sherry casks directly from the sherry producer in Jerez de la Frontèra, so we can always be sure of the desired quality. Once a barrel is filled with us, it stays in the barrel room in the distillery for at least 6 months. Most distillates only leave the barrel after 3 years. Some genevers such as the Oude Klare rest for a few months after distillation in old whiskey barrels, the Goeie Seeve for at least 3 to 4 years and matures in a mini solera system where we never completely empty the barrel. Our Aged Genever 7YO was aged for 6 years and 9 months in bourbon barrel, after which the last 3 months on sherry olorosovat to finish. Currently, many different distillates mature in different barrels in our room, without revealing what our oldest distillates are. Our oldest casks date back to the 1980s and are still used to rest and oxidize a distillate, not really to extract the aromas of the previous host.

All barrels in the distillery are made from oak. This can also be other types of wood such as hazelnut, mulberry, pine, green, acacia wood, etc. We have not yet experimented with this, but it will certainly be in the near future.

Mix of bourbon, whisky and sherry casks lying for a rest in the distillery in Aalst.

We are also planning to expand our barrel room this spring. This is moving to a new part of the distillery where we are building a barrel rack, which will provide 10 times more storage than our current capacity. So this year a lot is going to happen at Van der Schueren for the benefit of our barrels.

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