F - like barrel types

How many types of barrels are there at St. Kilian?

There is certainly no shortage of barrel types at St. Kilian. We now have over 370 different barrel types and sizes in our aging warehouses. For example, the bourbon barrel type with a capacity of 50 liters and 190 liters counts as two barrel sizes.

Does every distillery have such a variety of barrels?

Almost certainly not. We are one of the very few distilleries in the world with such a wide variety of different barrel sizes and wood types. This underscores the enormous willingness to experiment at St. Kilian.

Which barrels are mainly used at St. Kilian?

The most commonly used barrel at St. Kilian is the American Bourbon barrel. We have sizes starting at 20 liters through 50 liters to the standard barrel, the American Standard Barrel, with 190 liters of barrel capacity. American Bourbon barrels are made of American white oak, charred on the inside ("charring") in a cooperage, and then filled at the distillery with New Make Spirit known as White Dog. After years of aging, the bourbon barrels are emptied and offered for sale on the international market.

What flavors do used bourbon barrels give off?

When the former bourbon barrels from the USA come to St. Kilian in Rüdenau and are filled with our New Make, these barrels give off the typical bourbon notes of vanilla and caramel to the maturing distillate over the years of maturation.

What other barrels are available on the market?

Fortunately, an abundance of beverages, spirits and other products around the world are stored or aged in barrels. Barrels that have found their way to Rüdenau are, for example, those that were previously filled with sherry. These sherry barrels come from Andalusia in Spain, from the Jerez sherry region, and give off wonderful aromas of dried fruit, sherry, raisins, chocolate and spices. Other barrels used at St. Kilian are those previously filled with Apricot Brandy from Turkey. But we also fill former French Pineau des Charentes barrels, Sauternes barrels from Bordeaux, Mexican tequila barrels, Tabasco, herbal liqueur or bock beer barrels.

Do former wine barrels also find use at St. Kilian?

But yes. Especially red wine barrels are very sought after, because they give wonderful aromas of red fruits to the spirit and give it a trace of tannins, which harmonize very nicely with the matured whiskey and give it structure and mouthfeel. Red wines from France, Spain or Germany usually mature in 225 liter barrique barrels, wines from Burgundy in special 228 liter barrels. These types of barrels are usually made of European oak and were merely toasted before being filled with wine and not charred, as is the case with bourbon barrels from the USA.

What are the advantages of using pre-loaded drums?

During the pre-occupation with bourbon whiskey, sherry, port, wine or beer, the individual barrel staves have soaked up these liquids, as oak behaves like a sponge and eagerly absorbs liquid. If such a barrel is now filled with spirit of a higher alcohol content after it has been emptied, then in the course of the aging process these ingredients are extracted from the staves by the aging distillate and combined with it. The flavors from the pre-staging thus represent a source for the complex variety of flavors in the matured whiskey.

Are non-pre-aged casks also used for the aging of whisky?

But yes. Not every barrel made from American white oak and carburized is labeled "White Dog" (New Make Spirit) in the USA, but also sold. Such fresh, virgin barrels give off more intense wood notes to the maturing distillate. St. Kilian also has fresh, unused barrels made of Palatinate oak, Hungarian oak or the very rare Japanese Mizunara oak, which are filled with spirit in the aging warehouses. Since other types of wood besides oak are permitted in the European Union for the aging of whisky, we are allowed, for example, to use barrels made from the wood of a mulberry tree or Swiss pear tree, from wild robinia (pseudoacacia), from ash, cedar, chestnut or cherry. A wonderful example of the interplay of flavors from different woods and the influence of aging is the St. Kilian Signature Edition Thirteen.

What are the sizes of the barrels?

In the whiskey industry, the upper limit of a maturing cask for whiskey is set at a volume of 700 liters. The St. Kilian cask with the number 1 has this maximum volume of 700 liters. In the warehouses in our Bunker City, different types of casks mature in sizes ranging from 20 liters to just those 700 liters.

Does the barrel size influence the maturation?

Yes. The spirit matures much faster in smaller barrels than in larger barrels. This has to do with the surface area of wood available to the maturing spirit. According to the laws of physics, the smaller the barrel, the greater the ratio of wood surface area to spirit volume. This means that in a smaller barrel, there is more intense contact of the maturing distillate with the wood. In a larger cask, on the other hand, the spirit matures more slowly, more gently, and the whiskey becomes somewhat more harmonious because there is less wood influence. The loss of liquid from a cask during maturation ("Angel's Share") is higher in percentage terms in a smaller cask than in a larger cask.

How great is the influence of the cask on the maturing whisky?

Experts estimate that about 60 to 80 percent of the final taste of the whiskey is due to the influence of the cask during the years of maturation. But the quality of spirit and wood must be equally very high. After all, a poor-quality distillate with many off-notes will not mature into an outstanding whiskey even in the best wood casks. And conversely, a very good New Make spirit filled into a wooden cask of inferior quality (for example, a cask contaminated with mold) can at best produce only a mediocre whiskey.

How old can the barrels become?

Wooden barrels can become very old. Oak wood in particular is very hard and extremely durable. Without physical damage, oak barrels may well be in use for 100 years or more. An example of this are the solera barrels used for the maturation of sherry. With regard to whisky, a barrel is usually filled with spirit two, three or even four times in succession, depending on the philosophy of the distillery. However, with each occupation of the barrel, the influence of the wood on the aroma of the matured whiskey decreases, so that a further reoccupation of the barrel no longer makes sense from an economic point of view and it is sorted out. But it is precisely this lack of wood influence that is desired in sherry, because the oak of the solera barrel should not release any aromas to the wine, but only serve as a dense container. Thus, these solera barrels, which usually hold 600 liters and are usually made of American white oak, can certainly reach a very high age. Such solera barrels are highly aromatic and extremely sought after by whiskey producers. Because their over the very long time of maturation with ready-to-drink sherry soaked staves give off wonderful aromas to the maturing whiskey.