The production of whiskey barrels is a special art. Photo: e-fototapety.com

The art of making whiskey barrels is a highly specialized, traditional practice called cooperage. Today, modern equipment helps the cooper. However, he will need years of training and education to meet industry standards. Interestingly, the oaks for the manufacture of barrels are cut down only when they have reached sufficient maturity. Their height should not be less than 7.5 meters, and the diameter - 1 meter. After felling, the trunks are delivered to the sawmill. Here, boards are obtained from them, from which barrel boards are subsequently cut. Barrel boards are small planks with a complex curved surface that together create a round barrel.

Usually barrels consist of 32 boards, another 15 are used to connect the ends. To bend the boards to the desired shape, they are heated over a fire. Interestingly, in most American bourbon distilleries, it is customary to deliberately char the inside of the barrels. This is done in order to prevent the absorption of alcohol into the tree. The cooper cuts the boards so that they fit snugly against each other. This will help avoid leaks in the future. Interestingly, this is done without the use of nails or glue. The boards fit snugly together thanks to the metal hoops. Wood is a porous material, and distillers benefit from this, as they need the whiskey to interact with the air. That is why neither paint nor varnish is used to process the barrels. This allows the tree to "breathe". Finally, a hole is drilled on the side, which helps to monitor the whiskey aging process.

This is how bourbon is aged in the cellar of one of the American distilleries. Photo: leonhowlett.com

When buying a bottle of whiskey, we see that its label indicates the type of barrel used for aging. It is most likely that such information will appear on the label of an independent company. But what do the type and size of barrels really say? The main thing that a simple consumer needs to remember is that the smaller the barrel, the more whiskey is in contact with the tree.

Types of whiskey barrels

Specialized terms can be confusing to the average layman, so I present a small guide that shows the main features of the ten main types of barrels used in the production of whiskey.

Let's start with the largest format: Gorda (holds 700 liters). This is a huge barrel, which began to be used in the American production of whiskey. It is made from American oak. Traditionally, these casks are used for aging whiskey, but most often they are used for blending different types of whiskey in the production of blended whiskey.

The next format is called Madeira Drum. It holds 650 liters of liquid. It is a squat and thick barrel with a wide diameter. Manufactured from very thick French oak planks. As the name implies, these barrels are used in the production of Madeira. Sometimes they are used for the final stage of aging whiskey.

It is followed by Port Pipe, a 760 liter keg. It differs from the previous version in height and harmony. These barrels are made from thick planks of European oak. Port Pipe resembles an ordinary barrel stretched on both sides. Port wine is aged in these barrels. After that, they are used for the final stage of aging whiskey.

One of the 500 liter kegs was named Butt. This is a tall and narrow barrel, which is made of thick European oak. Such barrels are widely used in Spain for the production of sherry. This is the most common type of sherry casks used in the whiskey industry.

There is another type of barrel for 500 liters. This is Puncheon, which in turn is divided into two styles. The most common Puncheon is a stocky, thick American oak barrel. The second type is a more elongated barrel made of thin planks of Spanish oak. Both variants are used in the production of rum and sherry, respectively. Most often, whiskey ripens in them.

Also known is a 300 liter barrel - Barrique. It is widely used in the wine industry and is different from any other barrels. It is tied with wooden bands instead of the traditional metal hoops. Such a barrel is used to give whiskey the aftertaste of a wine barrel.

225 liters of whiskey fit in a Hogshead keg. Its name is derived from the English term "hogges hede", widely used in the 15th century. This was the name given to the unit of measurement, equal to 63 gallons. Today these barrels are made from white oak. They are used to age bourbon, and then sent to Scotland and Ireland. This is the most common type of casks used to age whiskey.

An ASB keg (standard American keg) holds 200 liters. This species evolved from the hogshead barrel. Its volume has been rounded up to 200 liters to make it easier to use in today's world. Produced by ASB from American White Oak. It is widely used in the production of bourbon, and more recently for aging Scotch and Irish whiskey.

Quarter Cask - 50 liter barrel. This type of barrel was made to be a quarter of the volume of the ASB, yet still proportional. It actively reacts with alcohol due to the constant contact of alcohol with wood. Used to quickly add aroma to whiskey.

And finally, the Blood tub, which holds 40 liters. This is a small barrel that is most often used for brewing. But sometimes distilleries use it to age special batches of whiskey. These barrels have an elongated oval shape, which is designed to facilitate their transportation on the back of a horse.

How does wood affect whiskey?

Numerous aromas and characteristics of whiskey comes from the wooden barrels in which it has been aged. Historically, any type of wood could be used to make barrels. But today, according to US law, they must be made of oak. Oak was chosen for its hardiness and ease of working with it. It has dense fibers that avoid leaks. And its porosity helps to penetrate oxygen.

Whiskey owes its aroma to various factors. Photo: wordpress.com

The tree is saturated with natural oils, which are known as vanillins. It is these oils that are drawn out of the barrel by alcohol, and during the maturation of the drink, they give the whiskey a peculiar fragrant note. But if all whiskeys are aged in oak barrels, how can they taste different?

The answer is simple. The taste of whiskey is also determined by the nature of the distillery, the ingredients used, the size and shape of the stills, and the geographic location. These are as important factors in the production of whiskey as the type of oak barrel.

In anticipation of the release of two posts, the cornerstone of which will be the aging of whiskey in various barrels, we decided to prepare a short digression into the history and industry of barrel production.

The history of cooperage skill goes back to ancient times. For many centuries, the barrel was almost the only container of this volume used to store almost all liquids.

No, of course there were wineskins, eggplants and so on. But, the barrel was a kind of analogue of a modern safe, in terms of reliability and trust in the most important and significant liquids for the society of those years, be it water, wine or ... of course, whiskey.

To date, the production of barrels is most developed in the United States. This is primarily due to the fact that US law clearly regulates the requirements for the production of the most consumed alcoholic beverage there - bourbon.

One of the requirements is that alcohol must be aged only in new (not used before) barrels. This means that for each new batch of whiskey it is necessary to produce more and more new barrels.

Many people think that aging in a barrel is more of a tribute to fashion, some kind of ingrained archaism, or a balanced and calculated marketing ploy. In fact, this is not entirely true, or rather not at all.

In this post, we will try to briefly talk about the types of barrels used to make whiskey, and the interaction between “water and the tree of life”.

On many bottles of whiskey, the manufacturer places information about the types of barrels in which the drink was aged. These can be barrels of bourbon, wine, even Jamaican rum, in which case what was in the barrel before the whiskey gives the drink its unique, unique taste, color and aroma. But, what is the effect of new casks on whiskey, and what is the difference between whiskey aged in American and Spanish oak casks?

In addition, do not forget that, in addition to the differences associated with what was in the barrel before the whiskey and the type of wood used to produce the barrel, the barrels themselves differ in size, displacement and, as a result, the area of ​​​​contact of the drink with the tree.

What does information about the barrel actually give us? The main paradigm looks something like this - “the smaller the volume of the barrel, the more intensively the drink interacts with the tree.”

Many of the flavor, aroma and color characteristics each individual sample of whiskey acquires from the cask.

Today, most barrels are made from oak. This is due both to the legislative regulation of this process, and to the convenience (in all respects) of working with such material as oak - it is durable, has sufficiently strong fibers, which prevents leakage of the precious drink (not counting the throats and stomachs of Angels), porous, which is the basis for the necessary circulation of oxygen, and so on.

The tree itself is a reservoir of natural oils. These are the same oils. which enter the whiskey during the aging process, and give the whiskey its unique organoleptic characteristics.

How is it that if all whiskeys are aged in oak barrels, then why do they all have different tastes, colors and aromas?

The nuances of whiskey production - the type of barley, the degree of peat fumigation, the size and shape of the stills and the water used to produce whiskey are certainly important, but the cask factor always remains the most important factor.

There are three main types of wood used to make whiskey barrels today.

European oak(Quercus robur)

Initially, English or Scottish oak was used for the production of barrels. The disadvantage of this type of trees is their slow growth and twisted, uneven trunks, which form the appropriate structure of the fibers and lead to the fact that barrels begin to leak over time.

Later, imported Russian oak was used for the production of barrels in Europe. It is more suitable for cooperage. First of all, due to the rapid growth of the tree and the straight trunk.

Beginning in 1860, the massive import of Spanish sherry to the United Kingdom began. The casks used for aging and transporting sherry were naturally made from Spanish oak, which in turn was very similar in characteristics to Russian oak but was much cheaper.

Traditionally, Spanish oak grows in the northwestern region of Spain - Galicia (capital - Santiago de Compostella). And although the production of Sherry has declined significantly, Spanish oak is still used for the production of barrels and is an extremely popular material.

A sherry barrel fills the whiskey with the taste and aroma of dried fruits, raisins, candied fruits, cinnamon, wood, caramel, orange and pastries.

Another type of wood used to make barrels today is French oak. As a rule, this type of wood is most common for the production of wine barrels. As a rule, used wine barrels made of French oak are used to “finish” whiskey, in order to fill it with a special, unique wine aroma and taste.

american oak(Quercus alba)

American oak began to be used in the whiskey industry only after the Second World War. It was at this time that US law established that bourbon can only be aged in new, previously unused wooden barrels.

Naturally, this state of affairs stimulated the US cooperage industry in the strongest way, which was in a state of collapse after the Prohibition period of the 1920s and 30s. The result of these regulatory changes has been the emergence of a huge number of barrels on the market.

The American whiskey industry was slowly recovering from the Prohibition-related stagnation and naturally the Scots and Irish began to use American barrels to age their whiskey.

In general, this is an extremely beneficial cooperation for both parties, including the economic attractiveness of bourbon casks, compared to sherry casks, the number of which is gradually decreasing, while the price is naturally growing.

American oak is an excellent raw material for the production of whiskey barrels. It grows fast, has large straight trunks, excellent wood and high oil content.

Barrel size (known as ASB - American Standert Barrel) is also optimal for whiskey aging.

The result of this collaboration was the popular inscription on scotch labels - “matured in American oak cask”, which today flaunts on almost 90% of whiskey bottles.

The main elements of taste and aroma that a bourbon barrel of whiskey gives are vanilla, honey, nuts, toffee, ginger.

Japanese oak (Quercus mongolica)

Also known as oak - "mizunara". Used in the Japanese whiskey industry. Of the well-known names, the first to come to mind is the bottling of Venture Whiskey, under the Ichiro Malt brand - “Ichiro Malt Mizunara Wood Reserve”. This bottling is a blend of Hanyu and Chichibu malt spirits.

The history of barrels made from Mizunara oak dates back to 1930. These casks give the whiskey its unique, inimitable properties.

Mizunara contains a huge amount of oils. But, at the same time, the tree is very dry and porous. All this leads to the fact that barrels made from Mizunara leak heavily and break easily. Now, most Japanese bottlings are aged in sherry or port wine barrels, and only then finished in mizunara barrels in order to acquire a unique, unique organoleptic.

Mizunara fills the whiskey with aromas and flavors of vanilla, honey, fresh fruit, apple, wood, flowers.

As we wrote, in addition to the type of material, whiskey aging barrels differ in type, size and shape. As a rule, merchants “sin” with experiments with types of barrels, sometimes using quite “exotic” things. Let's try to understand the main types of barrels used in the whiskey industry.

Gorda ( capacity - 700 liters)

A large cask typically used in the American whiskey industry. Made from American oak. It is used for aging whiskey, but usually for blending different types of spirits and producing blended whiskeys.

Madeira Drum (in capacity 650 - liters)

Short, thick, "stocky" barrel, very wide in diameter. Made from very narrow planks of French oak. As the name implies, it is mainly used for the production of Madeira, sometimes for finishing whiskey.

Port Pipe ( capacity - 650 liters)

Tall, thin barrel. Made from narrow planks of European oak. It looks like a standard barrel stretched on both sides. Used for aging Port wines and finishing whiskey.

butt( capacity - 500 liters)

Tall, narrow barrel made from narrow planks of European oak. Very widely used in the sherry industry in Spain. Butt the most commonly used sherry barrel for aging whiskey.

Puncheon ( capacity - 500 liters)

There are two types of these barrels. The most common one is " machine puncheon ” - a low, thick barrel made of American oak. The second type is sherry shape puncheon “higher, narrower is made from narrower planks of Spanish oak. They are used to age rum and sherry. Often used to finish whiskey.

barrique ( capacity - 300 liters)

The most commonly used barrel in the wine industry. A distinctive feature of these barrels is that they are fastened not with traditional metal “hoops”, but with a wooden band. Typically used to finish whiskey.

Hogshead ( capacity - 225 liters)

The name of these barrels comes from the English term of the 15th century - "hogges hede" which meant a unit of 63 gallons. Now mostly made from American White Oak. The casks are used to age the bourbon and then exported to Scotland and Ireland. This is one of the most commonly used barrel types for whiskey aging.

ASB American Standard Barrel ( capacity - 200 liters)

In fact, this is a Hogshead whose capacity has been reduced to 200 liters, in order to make it easier to use. Made from American White Oak. Naturally widely used for aging bourbons and very often used for aging Scotch and Irish whiskeys. If you see the inscription on the bottle - “matured in bourbon barrel (cask)”, this means that the whiskey was aged either inBarrel, which is proportionally reduced by four times ASB . It has a very strong effect with alcohol, since the contact between wood and drink is increased four times due to the small volume. Used to quickly “fill” whiskey with the necessary aroma and taste. Sometimes called " firkin ” (small barrel).

blood tube capacity - 40 liters V)

The smallest barrel. Most common in the beer industry. But, it is occasionally used in distilleries to age special spills and "limited runs". It has an oblong oval shape, the most convenient for transportation on horseback.

Drinks are most often judged by their taste. Tasting good whiskey, connoisseurs usually speak briefly: mature, soft.

With softness, perhaps, everything is clear, but with maturity it is more difficult, since this term usually means endurance. What is the optimal time, does the production method affect the aging time, how long should the drink be aged in a barrel in order to acquire the very maturity for which it will be appreciated.

A few words about whiskey

Whiskey is a natural product, it is based on cereals. Manufacturing technology looks something like this. Initially, from barley, rye, wheat, corn or millet - sometimes you can even encounter the use of rice or buckwheat, malt is prepared. It is dried, get the wort, which is subject to fermentation. The fermented mass goes through the distillation process, the resulting product is filtered and bottled.

From this moment, the countdown begins, which is then called the aging of the drink. After a certain period, if necessary, it is blended (mixed) and poured into that beautiful glass container that we see on store shelves.

The strength of whiskey is in the range of 35-60 degrees, the color is different: from light yellow to brown. It is highly valued - it is on a par with cognac, rum, vodka. The value is determined by the quality of the drink, which in turn depends on the aging - term, conditions. It is different for each country of manufacture. The minimum aging of Scotch whiskey is 3 years, Irish - 5 years, Canadian - 6. The original drink cannot be less than 10-12 years old, the collection - 21 years, and the rarest and most valuable varieties are aged from 30 to 50 years.

Aging depends on barrel

And to this day, opinions about what is the most optimal aging time for whiskey are ambiguous. Terms are called different, they are affected by the method of production. Only one rule remains unchanged: the longer the drink is stored in the barrel, the more its taste changes - it becomes colorful, saturated. If the whiskey is in a different container, then the time does not affect the quality.

In a barrel, under the influence of wood, taste, color and aroma are formed. This moment of birth, maturation of whiskey in its production is still considered the most mysterious and completely unsolved. After all, if you do not guess the aging period, make it shorter, then the result will be the most deplorable: instead of a noble drink, you get ordinary grain alcohol or moonshine.

The alcohol obtained from the grain is bottled both in new barrels made of oak and in those where other drinks were previously aged. Usually, noble, high-quality wines act as predecessors: port wine, sherry. The choice of a particular type of barrel rests with the master of the distillery.

In the barrel, the drink must be at least 3 years and one day. Only then can it be called Scotch whiskey. True, today this bar has been raised to 5 years, which is explained by increased quality requirements. During this time, porous wood constantly saturates the drink with tannins, and part of it evaporates, goes through the walls. In Scotland, these evaporations are called the "angels' share", how much liquid will evaporate depends on climatic conditions - humidity, temperature, etc. On average, 0.5-12.5% ​​evaporates per year.

The older, the more expensive

Whiskey is an elite drink, they drink it with pleasure. It is from vodka that people get drunk, drinking it in large quantities, and whiskey is characterized by small doses, relaxation, pleasant sensations.

Real connoisseurs of the drink understand it and pay big money for real quality. Instead, they get a special, incomparable taste and aroma, directly dependent on the method of production, bottling and aging of the product.

Let's say the whiskey produced by The Macallan has a whopping 64 years of aging. But the price of a serving of this drink is impressive - 60 thousand dollars. However, this is not the limit - for the oldest whiskey in the world, they asked for 1.4 million dollars.

It is believed that the older the drink, the less often it can be found, and its cost is correspondingly higher. However, experts say that properties do not always improve over the years, a certain peak occurs in development, which only a real, experienced specialist can feel.

For example, Scotch whiskey of the Lagavulin brand reaches its apogee in development by the age of 16, and another brand, Glen Grant, is sold with a five-year exposure. The reasons for this difference in the maturation of the drink lie in the characteristics of the distillation, the location of production and, of course, the barrel.

The most interesting thing is that when creating a drink, hardly any master expects that in 50 or more years he will be able to try it. A striking example is the company of Grant's David, where barrels that had been stored for more than 50 years were opened. The drink in them turned out to be amazing: it felt not only freshness, fruity notes, but also an unusual taste of birch bark. The drink retained its strength - it was 40 However, even the most experienced and old whiskey master could not explain how such a masterpiece came out.

This suggests that the creation of noble drinks is still a secret with seven seals. No one knows for sure what exactly happens in a barrel, and therefore it is impossible to give a full guarantee that after 50 years of aging you will get a unique, inimitable taste drink. This may be just one barrel in a million. And, perhaps, it is you who will be able to try this drink.

The relationship between the wood of the barrel and whiskey is the most important component in shaping the structure of the drink. It is the barrel that forms the color, aroma, taste of whiskey. Whiskey maturation is one of the most interesting and completely misunderstood processes that is hidden from us.

Cask - the basis that forms the character of whiskey

For aging whiskey, both fresh oak barrels and barrels in which other noble drinks have already been aged, such as port wine, American Bourbon, sherries, are used. Oloroso, Fino or Amontillado.

Oloroso- sherry from Spanish Andalusia, which, due to the characteristics of the must and the addition of a certain amount of alcohol, did not form a flair (a film of a special type of sherry yeast that forms on the surface of the drink in the barrel and prevents the drink from oxidizing) (its strength is 16% or more). Oloroso can be dry, semi-dry, or sweet, depending on the preparation method and when the fermentation is stopped.

Fino- Produced from Palomino grapes grown on chalky soil. After a careful selection of primary material, the most promising samples are fixed up to 15% and placed in solera. The entire aging process takes place under the fleur. This sherry is always dry. Its strength reaches 18%.

Amontillado- Fino aged after fleur died. Fleur can die from both harmful environmental conditions and the addition of additional alcohol. As a rule, the fortress of amontillado is from 16.5 to 18%.

Directly the type of barrel in which the whiskey will mature is determined by the master of the distillery.

Whiskey is considered to have a minimum age of at least 3 years and one day before it can legally be labeled as Scotch. However, the requirements for the quality of the drink that have developed over the years of production have raised the minimum standard for aging alcohols in a barrel to 5 years. It should be noted that after bottling whiskey ceases to mature. The unique cool climate of Scotland promotes the return of tannins from the porous wood of the oak barrel to the drink. Another interesting fact is the evaporation of whiskey during the aging process - part of the drink evaporates through the walls of the barrel. The Scots call this phenomenon.

Why oak?

One of the most common questions is “Why was oak chosen as the material from which casks are made for whiskey aging?” The reason why oak was chosen is the unique structure of its wood, extremely durable, which is very important when molding a barrel, and chemically saturated. Another feature of the oak structure is the absence of resin channels in the wood structure, which are so numerous, for example, in pine. The presence of resins would negatively affect the taste of whiskey.

But is it only the physical properties of wood that affect the maturation process? Of course not! An important factor is the process of return of tannins as a result of periodic seasonal changes in temperature, which creates a unique taste of whiskey.

The use of oak barrels allows you to achieve three effects that determine the character of whiskey:

• Oak gives taste and aromatic notes of wood to the drink. Often, in addition to astringent notes, the taste of whiskey can distinguish shades of fruit, vanilla and wood sugar (xylose).
• Oak absorbs unwanted flavors from the main bouquet, such as the taste of water.
• Oak interacts with the drink, transforms the “dry” properties of wood into an organoleptically balanced bouquet, forms a harmony of color, smell, and taste.

An oak barrel helps to convert tannin (a substance found in wood with pronounced tannic properties and a characteristic astringent taste) into acetals - substances with a fruity smell, and acetic acid into fruit esters.

There are 5 main components of oak that are involved in the formation of the drink:

1. Cellulose- practically does not affect the formation of the taste of whiskey, but ensures the strength of the wood fibers, and consequently, the barrel itself.
2. Hemicellulose- consists of simple sugars that are destroyed when heated, forms the basis of the bouquet and color (young whiskeys are usually colorless) due to the sugar contained in the wood, giving the taste a note of “charcoal” with a hint and aroma of caramel.
3. lignin- an element that binds cellulose in wood, when heated, gives notes of vanilla, smoke and spices.
4. oak tannins- play a significant role in the formation of the bouquet of the drink during maturation. In combination with oxygen, they form subtle aromas and transform into acetals.
5. Oak lactones- are formed from lipids contained in oak wood. This element adds charcoal, woody, and sometimes coconut notes to the flavor structure. It is lactones that give American bourbon its specific taste, since the concentration of lactones in American oak is much higher than in European species.

Is any oak suitable for making whiskey barrels?

As a rule, for the manufacture of barrels for aging drinks, coopers use three types of oak:

• white oak — Quercus Alba(another name for this variety is American oak). The most commonly used variety of oak used in the production of barrels for aging whiskey. The wood of this American oak is more saturated with lactones than the European variety, which, as a result, provides the drink with a richer taste.

• Rock Oak — Quercus Petraea— European type of oak. Especially common in France. Most often used for aging wine. Rich in tannins. Gives vanilla notes to the drink.

• Pedunculate oak — Quercus Robur- this species is also called Summer Oak, English Oak, Common Oak. European look. Among the regions where this species grows, Spain should be noted. Barrels made of Spanish oak give notes of raisins and prunes. Such barrels are used for aging cognac, sherries. Rich in tannins.

Among the factors influencing the bouquet of whiskey, the following should be noted:

• The growth rate of the “donor” tree from which the barrel is made;
• Method and duration of wood drying;
• Methods of roasting and tarring barrels.

Influence of oak growth rate: slower is better?

Almost all masters are convinced of the direct relationship between the growth rate of a tree and the quality of the drink, its taste and aroma, while in the production of whiskey this connection is practically not considered. The most common White (American) oak is fast growing. At the same time, slow-growing oak barrels are known to have some advantages, namely a higher content of oak lactones, which provides a return of vanilla and fruity notes, which is important in the production of whiskey.

Also, the method and time of drying the wood has a huge impact on the quality of the barrel. For the production of barrels, only well-dried wood is used. It is during drying that the composition of the elements is formed. It is generally accepted that drying in the open air is preferable to kilns, in which the wood loses tannins and lactones. Often, in the production of high-quality wines, a tree is used that is dried in a natural environment for 24 months. At the same time, the wood for most bourbon barrels is dried in special dryers in just 2 weeks. Why? The fact is that most whiskey masters believe that the drying of wood has the greatest impact on the quality of the drink of the first filling of a new barrel, i.e. sherry, wine or bourbon, and has little to no effect on whiskey maturation. It should be noted that Scotch whiskey matures only in barrels that have already aged the base drinks.

Heat

Heating is an essential part of the barrel making process. Wood fibers have a certain elasticity and must be heated to give the barrel the desired shape. An open fire or steam is used to heat and give plasticity to the tree. The shape of the barrel is held by six metal hoops of various diameters. After shaping, the barrel is fired, causing wood sugar to crystallize in the wood.
There are some differences in the production process of bourbon and sherry casks.

Bourbon barrels

The finished molded barrel is additionally fired, as a result of which a black layer of soot (charcoal) forms on its inner surface. The time of this firing, that is, the thickness of the soot, affects the elements contained in the wood, and therefore the formation of taste. It should also be noted that the coal formed on the walls removes sulfur compounds from the drink. As a rule, the firing time is from 40 seconds to 1 minute, although some masters have experimented by increasing the firing to 4 minutes. The result of firing is a change in the structure of the inner surface of the barrel.

Barrels for sherry

Unlike bourbon casks, these casks are not further roasted. As mentioned above, the most popular basis for maturation of Scotch whiskey is an Oloroso sherry cask. Sherry casks can be made from American oak, although such casks are used to age Fino sherry and are not later used to make Scotch whisky. It is generally accepted that European oak is more saturated with elements than American oak. Aging in sherry casks gives the whiskey a fuller, richer flavor than American bourbon casks.

A little more history

The use of bourbon barrels to age whiskey is a relatively new phenomenon. The first experience of using such barrels dates back to the 30s of the 20th century. The reason was interruptions in the supply of sherry casks due to the Spanish Civil War. Currently, about half a million bourbon barrels and only about 20,000 sherry barrels are used to age whiskey.

It should be noted that very few whiskeys are aged exclusively in bourbon casks - most "bourbon" whiskeys are blended in varying proportions with sherry casks.

Barrel size

There are three main barrel sizes used in the aging process of whiskey:

• Barrel (Barrel) with a volume of 190 liters;

• Hogshead (Hogshead) with a volume of 245 liters;

• Bats (Butt) with a volume of 500 liters;

There are also such varieties of barrels as Puncheon (like the Butts barrel, it has a volume of about 500 liters, but wider and lower), Quarter (about 140 liters) and the smallest Octave (just over 50 liters.)

The Butts barrel is used in the production of sherry, Hogshead - bourbon. It should be noted that there is a direct relationship between the size of the barrel and the rate of maturation of whiskey - all other things being equal, the larger the barrel, the slower the maturation of whiskey. With small barrel sizes, the aging process is faster. A perfect example of this addiction is the excellent whiskey Laphroaig Quarter Cask.

Some whiskey producers, such as William Grant & Sons Ltd., use their own barrels, and some of them reach 2,000 liters!

Step by step

After the barrel has outlived its first life, taking out bourbon or sherry, it is ready for its second life - to become the cradle of whiskey. Barrels are sent to Scotland. An interesting fact is that when transporting bourbon barrels, as a rule, they are disassembled into separate boards, while sherry barrels are transported as a whole. After the bourbon barrels are assembled, some manufacturers re-roast them.

Barrels can be used to age multiple batches of whisky. On average, barrels are retired after two fills, but there are batches that can withstand 3 or even 4 fills with quality. It happens that after the barrel stops giving itself to whiskey, its inner surface is “cleaned” in a special way to refresh the wood, and re-fired, thereby giving the barrel another life. The quality of the barrel is controlled by the distillery master before each filling. It may seem strange, but a cooper is a difficult and responsible profession. Almost all distilleries impose strict requirements on masters - the cooper's training period is about 5 years.

What's after whiskey?

The question may arise - what's next? What happens to the barrel when it has given all of itself? Naturally, part of the barrels is dismantled and burned, as the wood simply rots, and part of the barrels goes to the needs of the “local population”. But there is another option!

McKay Flooring enthusiasts from Glasgow, Scotland have developed a technology that allows you to straighten the boards after the barrel has been decommissioned and dismantled, and use them for the production of parquet! Its cost is relatively high - about 300 euros per sq.m. Unfortunately, the use of such floors in residential areas is most likely not the best idea due to the possible peculiar smell that cannot be completely removed.

The barrel rightfully occupies one of the most important places in the process of forming whiskey. Born in Europe, within a few years she forms Spanish sherry, and then overcomes thousands of kilometers of sea to take in several generations of whiskey already in Scotland. The life of a barrel is decades of hard work every day.

5. Distillation.

Except for Auchentoshan and Hazelburn with their triple distillation and Springbank, Benrinnes, Mortlach with partially triple distillation (some alcohols are distilled 2 times, and some - 3 times). Scottish distilleries practice double distillation. This means that the two cubes usually work in pairs: the mash distillation cube is called wash still, A the second, at the output of which ready-made alcohol is obtained, is called spirit still. These cubes are made of copper, which is important. The reactions that take place between copper and alcohol reduce the content of unwanted impurities, and the longer the contact of alcohol with the cube, the cleaner it will be. In this regard, it can be argued that most manufacturers are striving to increase such contact. But this will not be entirely true, because in addition to undesirable impurities, useful ones are also reduced, which are responsible for the nature of the bouquet, so if you want to get a full-bodied and strong drink, you should keep these important compounds.

From the fermentation tanks where fermentation took place, the mash, usually preheated, is pumped into the first still. After that, it heats up and the first distillation begins.

There are several ways to heat a cube. The most popular now is steam. Steam that has been heated by oil or gas is supplied under the base of the cube through special steam pipes (steam coils). The steam pipelines, in turn, are connected to special containers of round, rectangular shape or even in the form of plates, which heat the mash.

Some manufacturers continue to use the old method of heating over an open fire. For example, at Glenfiddich and Glenfarclas all cubes are heated by an open fire using gas, and at Springbank only a part of the cubes are heated directly with oil, and the rest with steam. The only downside to this method is that solids can burn on the inside of the cube, which can affect the taste of the drink. To avoid this, a special device is installed inside the cube, which scrapes burning particles from the surface.

When the temperature in the cube reaches 95 degrees, alcohol vapors begin to rise to the top, but before talking about further processes, let's look at the various pot still shapes.

There are three main types:

Bulb (traditional cube)- the name speaks for itself, a cube in the shape of an onion.

boiling ball- with a special bulge in front of the neck of the cube, to increase reflux.

Flashlight- with a special "narrow waist" in front of the neck of the cube.

In addition to these three main types, there are many variations of narrow and wide cube necks, and the slope of the pipe connecting the cube neck to the condenser can be different.

The reason for such a wide variety of shapes and sizes is that these factors determine the length of contact of the distilled product with copper, and also affect the rate of reflux during distillation. Reflux is a term that means the re-distillation of alcohol vapor.. A high or narrowed neck, a large angle of inclination of the connecting pipe, will lead to the fact that heavy alcohols will not reach the cooler the first time, and, having gone down, will be subjected to repeated distillation. This process produces a lighter alcohol.

The boiling ball (boiling ball) gives more contact with copper and also allows you to get a lighter alcohol than in the cube of the onion type. The lantern-shaped cubes also increase contact with the copper and prevent evaporating and foaming mash from getting into the neck of the cube. If this happens, then the distillation can be considered a failure. To avoid this, the cube is only filled to 60-80%. This process is controlled with the help of special "windows" installed on the neck of the cube, which show the level of filling, and if it starts to grow, then the heating temperature of the cube should be reduced.

After the alcohol vapors overcome the neck of the cube, they enter the cooler through the pipe, where they condense and go to the receiver. The resulting liquid contains just over 20% alcohol and is about a third of the volume of the original mash. In the receiver, tails and heads from the second distillation are added to it, as a result of which the fortress increases to 28%, which is very important for further distillation. If this is not done, then after the second distillation, alcohol with a strength of no more than 60% will be obtained, which is very small in order to isolate from it the necessary fractions containing compounds important for the character of whiskey. With a strength of 28%, alcohol after the second distillation will exceed the level of 70%, which is a necessary condition for obtaining good alcohol.

After mixing, the result of the first distillation, which is called low wines it is pumped into the second cube, where, as a result of heating the walls of the cube, it acquires a fortress equal to approximately 82%. The risk of foaming, unlike the first distillation, is minimized due to the absence of carbon dioxide in low wines. On the other hand, during the second distillation, temperature readings play a more important role. The high temperature will reduce reflux and more heavy compounds will enter the cooler. Depending on the desired character of the alcohol, this can lead to undesirable consequences.

Traditionally, alcohol vapors condensed into serpentine. This is a large pipe from 3 to 5 meters in length, made of wood or cast iron, and located outside the room. Inside this pipe, filled with water, is a copper spiral, which sometimes reaches 120 meters in length. Alcohol passes through this spiral, being cooled by water. This method is still preserved in 13 industries in Scotland.

A more modern cooling device, the shell-and-tube condenser, is a large tube inside which water flows through small tubes, which cools the passing alcohol vapors.

Alcohol safe consists of two parts (by analogy with cubes) - wash safe (first distillation) and spirit safe (second distillation). The entire result of the first distillation is collected in a glass container with a hole in the bottom. The result of the second distillation is divided into three fractions - heads, heart, tails. Through the tubes, they enter one of two glass containers. Previously, you had to manually switch the direction of distillation - now it's the job of the computer.

The first part of the distillation is called the heads, they go for the first 15-30 minutes and have a high content of undesirable impurities and heavy compounds and can destroy the finished alcohol if they get into it. So this 75-80% alcohol portion is sent back to be mixed with the first distillation for re-distillation.

The next part, the hearts, contains up to 100 different aromatic compounds that give the alcohol its fruity character. This part is sent to the intermediate receiver and further to the shutter speed.

The third part, the tails, is initially necessary for alcohol, but then the level of undesirable components in them increases and at this moment the distiller (or computer) switches the pipe and sends it to the first container (where the heads are kept) for re-distillation.

Obviously, the definition of the beginning and end of the hearts plays an important role in shaping the bouquet of the drink. To do this, use hydrometers that measure the alcohol content. This fact is taken into account for the formation of the character of whiskey and the length of hearts varies from manufacturer to manufacturer. For example, if you want to get a fruity, floral whiskey, the distiller will start collecting hearts at 75% and stop at 68%. If you want to make a heavy and spicy whiskey, then you need to collect hearts in the range from 70% to 60% or even lower. At the moment when the hearts are going it is important to slow down the cube as much as possible in order to increase the reflux. It usually takes about 2-3 hours.

Hearts are often called "fresh alcohol" (new make spirit), which has a strength of about 70%. Fresh alcohol is pumped to an intermediate alcohol receiver and then to an alcohol vat, where alcohols of several distillations are mixed. The spirit vat is located in the room where the casks are filled, which is the last step before the whiskey is aged in casks.

6. Exposure.

The freshly distilled alcohol is diluted to approximately 63.5% before being released into wooden barrels for aging, a strength that has recently been considered ideal. With a higher strength, maturation will take longer, and the formation of some compounds important for the bouquet of the future drink will be difficult. Despite this, some manufacturers now bottle alcohol at a higher strength or do not dilute at all. This allows you to use fewer drums and, consequently, space in the warehouse. Other producers for many years do not dilute whiskey before bottling. For these reasons, it is possible to find cask-strength bottlings that, after more than 20 years of aging, retain above 60% ABV. If you fill the barrels with alcohol diluted to 63.5%, then after two decades the fortress will drop to 50% or even lower.

The evaporation of drinks during aging in barrels is also called the angel's share. About 1.5-2% evaporates annually in Scotland. Oak is a porous material and alcohol, as well as water, evaporate during aging. The angel share directly depends on the temperature in the warehouse. A higher temperature will give more evaporation. Humidity also plays a big role. High humidity means that the water will evaporate more slowly than the alcohol, leading to a decrease in alcohol content over the years. Scotland has high humidity, especially in winter. In other places, such as the southern United States, humidity is low, which causes more water to evaporate than alcohol, and as a result, the strength of the drink can increase during aging.

7. Oak and barrels.

The influence of wood on the final character of the whiskey cannot be overestimated. Often, about 80% of the bouquet of whiskey comes from the cask. After dilution, the alcohol is poured into wooden barrels, which, according to the Scotch Whiskey Act of 1988, must be made of oak. Sometimes in other countries other types of wood are used, just as in Scotland itself they tried to use barrels, for example, from chestnut. There are more than 400 varieties of oak barrels (quercus), of which about 200 are in the United States. But for whiskey producers, only 3 of them are of primary interest:

Pedunculate oak or English oak (Quercus robur)

Rock Oak (Quércus pétraea)

White oak or American oak (Quércus alba)

The first two grow in Europe, and the last, respectively, in North America, mainly in Arkansas, Kentucky, Missouri and Tennessee. American White Oak is valued for its value. The trees grow fast, have a fine grain structure, which means that they can be sawn rather than chopped with an axe. Which also means that less wood materials go to waste.

European oak, on the other hand, is more porous, which means more evaporation during aging, as well as more oxygen enrichment, often to the benefit of the matured beer. Also, European oak contains more tannins, and American oak - vanillin, which affects the bouquet of whiskey.

The fourth species of oak that is now gaining interest is the Japanese or Mongolian oak (Quercus mongolica), also known as the Mizunara oak. After the Second World War, there were difficulties with sherry casks in Japan, and some producers decided to use a local variety of oak to age their drink. They were not satisfied with the results of such experiments, and as soon as the Spanish barrels returned, they began to use them. Decades later, however, they discovered that whiskey aged in Japanese oak had a unique bouquet with hints of sandalwood and cedarwood, and now many distillers in Japan have begun to use Japanese oak to some extent.

The importance of the influence of oak on whiskey aging can be summed up in three parts: subtraction, addition, interaction.

a) subtraction

During exposure, the destruction and removal of sulfur compounds from alcohol occurs. In fact, this is not due to oak, but due to the carbon formed on the inner walls of the barrel during its firing. In order to assemble the barrel, the boards are heated to a burnt state. For bourbon barrels, this is not enough, after the barrel is collected, it is treated with an open flame, as a result of which the inner walls of the barrel are charred 1-3 mm deep. That is why such barrels are more effective in reducing the sulfur content in alcohol.

b) Addendum

The cask gives the drink both color and bouquet, and it conveys oils, acids, sugars and fats to varying degrees that affect the whiskey's bouquet. Another addition to the bouquet refers to short aging or "finishes", in this case it comes not from the barrel itself, but from the drink that was in it before (for example, wine, sherry, port, etc.). Depending on how many times the barrel has been used, its effect will be different. The tannins contained in the tree affect the color of the drink, and European oak will give a darker color than American oak.

c) Interaction

Of the three, this process is the least understood. Evaporation and oxygenation (when oxygen replaces the evaporated water and alcohol) tend to reduce harshness and add complexity to the alcohol. In addition, when the barrel and alcohol interact, new compounds are formed. If the first two types of influence act during the first two years of exposure, then the interaction occurs throughout the entire exposure and strongly depends on the conditions under which it takes place (temperature, humidity, atmospheric pressure).

Previously, manufacturers used the barrels they could find, because they considered them as shipping containers. At the end of the 19th century, there was a fashion for the use of Spanish sherry casks. Large quantities of sherry were imported into England, and casks were cheap. In the middle of the 20th century, sherry imports dropped significantly, and whiskey producers tried to find another solution. Some of them started making their own casks in Spain, then renting them out to sherry producers for aging and then shipping them to Scotland. Others began to use American bourbon casks, which by law must only be aged in new charred casks.

Approximately 18 million barrels of whiskey are aged in Scotland and 95% of them are made from American oak and every year 300,000 of these barrels enter Scotland from the USA.

It is important to understand that when it comes to choosing a cask, it is not the influence of the bourbon or sherry itself that is taken into account, but the influence of the casks used to age them.

With a few exceptions, the spirit that becomes whiskey is poured into barrels that have already been used at least once to age another strong drink or wine. If you use a new oak barrel, you should be very careful, because there is a chance that the oak will overcome the bouquet of alcohol.

Bourbon, sherry and other drinks soften the oak during aging and help convert the various polymers in the wood into aromatic compounds. It is obvious that bourbon with its high alcohol content and relatively low alcohol wines affect the barrel differently. Different alcohol content allows you to extract and convert different compounds. If you take an American oak barrel and a European oak barrel, both of which previously contained sherry, you will notice that they will give the whiskey different flavors. American oak, for example, will give hints of vanilla and coconut, while European oak will give ripe fruits and tannins.

During the last two decades, new types of casks have been used, not just bourbon and sherry. Today it is not difficult to find whiskey that has been aged in port, Madeira, rum and various wine barrels. Sometimes whiskey matures in one barrel for the entire time, but most often the whiskey is poured from a sherry or bourbon barrel into another for a final exposure, which lasts from two months to two years.

Barrels are also divided according to the number of uses. If the cask is used for aging whiskey for the first time, then such a cask is called a first fill cask (First fill cask), then comes a second fill cask (Second fill cask), if the cask is used for the third or more times, then it is called a refill cask ( re-fill cask). First fill casks should be used with extreme caution, as the oak and/or the liquor that was previously in the cask can greatly affect the flavor of the whiskey. Barrels of the second and third fills have less effect, so they are easier to use in blends and single-barrel fillings. After each use, most bourbon barrels are re-sanded and fired to create a fresh carbon layer on the inner walls. Sherry casks are also charred and sometimes refilled with sherry.

8. Blending and bottling.

If we exclude single-cask bottlings, which, as the name implies, are bottled from one cask and most often at cask strength, all Scotch whiskey is blended, even Single malt. Blending called mixing two or more barrels before bottling. This process varies quite a lot among different producers, including depending on what kind of whiskey is produced: blended or malt, but the basics are the same everywhere:

the contents of several barrels are poured into large vats, where purified air is passed through it to mix the spirits. This process is called rousing. After that, the whiskey is diluted with demineralized water to the required strength, the value of which cannot be lower than 40%. After the next stage, which is the tint, the blended whiskey is sometimes sent to "marry", which can last up to 12 weeks. Tinting whiskey is carried out by adding caramel (E150). Some manufacturers do not use this method, others do, others only use it for part of their products. Whiskey is tinted so that it is always the same color, or to make the whiskey seem more seasoned. Some argue that the addition of caramel affects the taste.

After the caramel has been added, the whiskey "marries" again within 10-15 minutes. The next step is filtering. All solids that have entered the whiskey from the barrel are filtered out mechanically. Cold filtration (chill filtration), as an additional cleaning method, is a controversial process, as is artificial tinting. It is the cooling of whiskey to a range of -4 to 2 degrees, which makes it cloudy. This turbidity consists of various fatty acids, which are subsequently filtered out. This is done so that when water or ice is added, the whiskey does not become cloudy, and also for purely cosmetic reasons.

Contrary to these arguments, there is the fact that filtration deprives whiskey of important aromatic components. The degree of this influence depends on the temperature, the size of the filters and the speed at which the whiskey passes through them. Independent bottlers almost never use cold filtration, and some producers produce whiskey without cold filtration (unchillfiltered).

After cold filtration, the whiskey is bottled. Like blending, this is a standard procedure, but the details vary from producer to producer and sometimes from one producer to another. Recently, the absence of cold filtration and touch-ups have been a strong marketing weapon for those manufacturers that are oriented towards advanced buyers.