IT'S THE CASKS THAT MATTER

 CASKS USED FOR MATURING WHISKY

THE BASICS 

Maturation in casks to provide taste, colour and provenance is one of the main reasons whisky is so widely popular across the globe. Interactions between the organic compounds in newly distilled spirit and the chemical compounds in wood produce a wide and complex range of flavours, and aging it in different types of wood can create incredible variations in taste. This is a crucial fact to pay regard to, since the raw make that enters the Spirits Safe has an obnoxious taste which has to be cautiously and continually nurtured, first to an acceptable and then to enticing taste. Evidently, whisky gets much of its flavour from the wood it’s aged in. If many different types are used, what do they add? The key points about whisky maturation are:

• The number of times the cask has been used–the more times, the less flavour will be imparted.

• The size of the cask–the greater the surface-area-to-volume ratio, the more flavour the whisky will get.

• The time spent in the cask–more time means more flavour extraction.

• The intensity of the spirit–a lighter style will get more influence from the wood than a heavier one.

CASK SIZES AND COMPONENTS

The bigger the cask, the longer it takes the liquid inside to mature.

Barrel, 180–200 litres, also known as an American Standard Barrel (ASB), is commonly used for bourbon. These are made from American oak.

Hogshead, 225–250 litres, is made by taking part ex-bourbon barrels to create one bigger cask. The Scotch whisky industry often prefers larger casks for ageing as this allows more whisky to be aged in the warehouse.

Madeira Drum, 600–650 litres, is made from French oak and used for Madeira wine.

Port Pipe, 550–650 litres, is made from European oak, and as the name suggests, is used to age port wine.

Sherry Butt, 475–600 litres, is made from American oak, although some are made from European oak. Butt is the most common size used for ageing sherry.

Barrique, 250–300 litres, is widely used in the maturation of wine and cognac. Barrique is mainly made from French Oak.

THE AGEING PROCESS

The ageing process can be broken down as follows:

• The temperature in the warehouse fluctuates day-by-day and during the changing seasons

• The resulting pressure change forces the whisky into the pores of the wood by way of the charred interior surface

• The whisky reacts with air/water and undergoes a chemical reaction that breaks down some of the organic compounds in the wood

• Some of the ethanol and water evaporates as part of the reaction and exposure to air causing the “Angel’s Share” to leave the barrel

• The wood constituents and whisky diffuse back into the barrel as the warehouse environment fluctuates

• Convection currents mix the contents of the barrel and the whisky turns darker brown as the cycle repeats

NUMBER OF FILLS

Bourbon must be aged in new oak, so when whisky is aged in a 1st fill ex-bourbon barrel, this means it is the first time that malt whisky has gone into that barrel after bourbon. In this case, the whisky will be heavily influenced by the wood, and therefore the spirit is only left in the barrel for a short period to avoid heavy wood influence. This can be around five years.

In Scotland, the same cask can be used for years and years, although it is uncommon for the cask to be refilled more than three times. So obviously, after the 1st fill you will have a 2nd fill, which averages around eight to twelve years, and, confusingly, the third and final fill is known as the refill. After the 3rd fill, the inside of the cask can be shaved to show new wood before re-toasting and charring.

Some distilleries will even put a cask back into service for a fourth filling, depending on the spirit and intended purpose.  5th and 6th fill casks definitely exist, but it’s considered uncool to talk about them. Most of them land up in the three-year grain whisky maturation process.

With the massive boom in the whisky industry and demand for casks at an all-time high – plus the cost of casks increasing accordingly – tired casks that might once have been discarded are now being rejuvenated to get a second lease on life. The internal surface of the cask is scraped back to fresh wood, then re-charred to re-instate the all-important charcoal filter. “De-char, re-char” is the common phrase and process in Scotland, and many casks will also receive a level of toasting prior to re-charring, in order to better break down the wood, release the vanillins, and soften the tannins. An example of Loch Lomond techniques regarding 'Charring' will follow. Casks or whisky releases noted as STR undergo this process, with STR standing for Shaved, Toasted, and Re-charred.

Long-term maturation in 2nd fill casks allows the magical interactive process to really play out without the additive process becoming over-bearing or upsetting the balance. Single malts matured from 15 to 25 years in 2nd fill casks produce some of the finest results.

Glenfarclas prefers 2nd fill casks, and believes that the best Glenfarclas whiskies come from refill casks.  Glenfarclas, of course, is famed for maturing its whisky in ex-sherry casks, and the distillery is careful to ensure that 1st fill casks aren’t left for too long.  The danger is that the sherry-influence would over-power and dominate the spirit.  Most releases in the Glenfarclas portfolio (e.g. the 10yo, 12yo, 15yo, 17yo, etc, etc) are thus a careful vatting of casks that combine 1st fills and re-fills; American oak and European oak.  Macallan goes down a similar route with its Double Cask range, further introducing the influence of ex-bourbon casks in its Triple Cask Matured range

MORE ABOUT OAK

Maturation of whisky in oak is a three-pronged action that requires three different processes to occur. These three processes may be summarised as being additive, subtractive, and interactive. They are worth elaborating on:

Additive: The cask will add flavour and character to the spirit.  Wood sugars, oaky notes, tannins, the influence of the previous filling (e.g. sherry), and colour will all be added to the spirit.

Subtractive: The cask will subtract certain volatiles and compounds from the spirit, making it more mellow, softer, and approachable.  Casks are typically charred before being employed in the drinks industry; the charred wood acts as a natural filter that removes undesirable compounds such as sulphur.  (As an aside, this is why the distilleries that produce a more sulphury new-make often benefit from longer years in the wood).  Other volatiles in the spirit, some of them undesirable, will be lost through evaporation.  The “Angels’ Share” is the lighthearted term given to evaporation, but it’s a serious matter for whisky producers in warmer climate countries:  Filling a 200 litre cask with your precious spirit and only having 100 litres of it left in the cask after five years is a challenging issue.  

Interactive: This is where the magic happens. Certain chemical and molecular reactions occur between the wood, the spirit, the residuals left by previous fillings, and – most importantly – oxygen, to create new flavours/aromas. The casks breathe; the spirit oxidises; and the oak and spirit transform one another. This interactive process can be where the different oak species produce different results, as they vary in the nature of their chemical and biological make-up: The differing characteristics of the wood’s density, permeability, hemi-cellulose, lignins, tannins, oils, lipids, and so on, will all impact the spirit differently. Despite the modern Scotch whisky industry being more than 250 years old, commentators and industry professionals believe that this third interactive process is only just now starting to be understood from a scientific perspective.

Time is therefore of the essence, and due time is needed for all three of these processes to play out.  Three years is the minimum period of maturation stipulated by law in Scotland, which was set as a minimum benchmark for quality….although the climate and production regimens in Scotland generally dictate that most whisky will take 8-15 years to peak.  Climate and environmental conditions (namely heat and humidity) obviously have a large influence on maturation – particularly evaporation – and so different countries factor this into their production methodologies and timescales.  There’s a truism that whisky matures faster in hotter countries, but it’s important to understand the difference between true, three-pronged maturation and simply base evaporation and taking on colour.

Evaporation over time is a complex problem for distillers, and it differs the world over, subject to the local climate – particularly the local humidity.  The conditions in Scotland lead to the alcohol evaporating faster than the water within the spirit, meaning that the alcohol content of the whisky decreases with time.  In contrast to this, the conditions in Kentucky, USA, lead to the water evaporating faster than the alcohol, meaning that the alcohol content of the spirit actually increases over time! 

One of the challenges for the so-called new world whisky producing countries is to find the balance or sweet spot with their maturation programs whilst juggling the many forces, demands, and financial factors at play for start-up operations.  For new distilleries wanting to bring aged whisky to market sooner and bring in much-needed cash flow, there is temptation and a growing tendency to adopt small-cask maturation in active casks to supposedly fast-track the process.  However, as many distilleries in Australia have found to their detriment, aging spirit in 20L or 50L casks for just over two years in ex-wine casks might produce a dark whisky that initially seems ready to some drinkers, but the reality is that only two of the three maturation processes discussed above have partially occurred:  The additive and interactive processes have occurred to some extent, but there simply hasn’t been sufficient time for the subtractive process to fully play out.  The result is often hot and dry whisky that is over-oaked yet under-matured.    

The situation is exacerbated at distilleries who insist on using ex-wine casks that have only been toasted, rather than heavily charred, meaning that their casks are less capable of removing (subtracting!) the volatiles and other aggressive compounds that maturation seeks to address.   (Hence leading to whisky that is described as “hot”, regardless of the actual ABV percentage.)

Fans of peated whiskies should also be aware that peatiness decreases over time.  The phenol levels in the spirit reduce with years in the wood (there’s that subtractive process again!) and so those wanting to experience the real “smoke bombs” should be seeking younger whiskies and not necessarily older releases.

Only oak may be used for the storage of Scotch whisky. There are two main types of oak used for barrel making and another two used for variety, i.e., less often.

Type of Oak	Flavour Influence
American white oak (Quercus alba)	Vanilla and caramel, soft and mild
European oak (Quercus robur & petraea)	Spice and bitter notes
Mizunara Oak (Quercus crispula)	Sandalwood, coconut and oriental spices
Maple (Acer)	Sweet, maple syrup

American white oak is found mainly in the eastern USA and parts of Canada and is used to make the barrels for bourbon and Tenneessee whiskey. Its growth is relatively strong for oaks. The wood has a high density of 770 kg/m3and contains a lot of monogalloyl glucose, which is responsible for the typical vanilla notes in bourbon.

European oak, on the other hand, grows more slowly and has a lower density (720 kg/m3) than its American relative. The gallic acid contained is a plant tannin and belongs to the gallotanins. It causes the bitter notes in whisky. European oak gives off much stronger and spicier aromas than American white oak. It is mainly used to make barrels for European wines and strong wines such as sherry.

Mizunara oak is very widespread in the forests of Northeast Asia, where it is mainly used for high-quality furniture. Due to its high density and thin fibres, the staves have to be cut along the fibres, which never grow completely straight. In addition, oak lacks waterproofing oil enzymes, so much more whisky evaporates during maturation than when matured in American or European oak. Despite these characteristics, which make it much more difficult to use for whisky casks, Mizunara oak gained popularity for whisky maturation in the early 20th century, not least because of the special aromas it gives off to the whisky, which are reminiscent of sandalwood, coconut and oriental spices, for example.

Maple grows in large parts of the world, including Eurasia, North Africa, Central and North America. With its relatively low density of 653 kg/m3, it is mainly used in the production of Tennessee whiskey: this is filtered through a charcoal layer of sugar maple before being stored in barrels, which makes it particularly smooth. In addition, some American whiskey producers mature their brandy in maple barrels to give the whiskeys the sweet notes of maple and maple syrup.

While only oak may be used in the most important whisky-producing countries of Scotland and the USA, other types of wood, such as chestnut, are also used in other countries.

COMMON TYPES OF WHISKY CASK

Bourbon

Bourbon barrels are made from American white oak. They go through both toasting and charring before the bourbon is added. Also, the ABV level of the bourbon will impact the flavours of the barrel – the higher the ABV, the bigger the impact on the wood. Basically, the higher alcohol level will strip the barrel of the benefits of toasting and charring, leaving less flavour for the next spirit.

Bourbon barrels are the most common cask used for Scotch whisky. Why? It’s all down to supply and demand. By law bourbon must be aged in new casks, meaning that after their first use they are generally surplus to requirements. They are also cheap compared with other types of cask, which leads to high demand from Scotland (and other distilleries around the world). For example, the exclusive Balblair 1997 from Gordon & MacPhail shows the classic sweet, fruity style that bourbon casks impart along with the trademark notes of coconut and vanilla. The charcoal in the cask softens the bold flavours from the distillation process during the charring process. Depending on its tastes, each distillery uses varied toasting and charring. Used bourbon barrels are typically burned for 40 seconds, though this can occasionally increase to 3 minutes. The more char there is, the easier it is for the spirit to enter the pores of the oak.

The charcoal in the cask softens the bold flavours from the distillation process during the charring process. Depending on its tastes, each distillery uses varied toasting and charring. Used bourbon barrels are typically burned for 40 seconds, though this can occasionally increase to 3 minutes. The more char there is, the easier it is for the spirit to enter the pores of the oak.

Sherry

The sherry industry avoids using new oak, and most of the casks used in Solera are at least ten years old. These casks have been seasoned with wine before being used for sherry. Different varieties of sherry get their unique flavour through a range of ageing methods. For example, oloroso has contact with air, which contributes to the fruity and nutty flavours, while fino is protected from the air by a layer of yeast, also known as flor, and this keeps the sherry light and crisp. Pedro Ximenez (PX) gets its sweetness from the raisins; the grapes are left to dry in the sun before being fermented.

It is not uncommon for a whisky distillery to buy European oak (mainly Spanish), have the casks coopered in Jerez and filled with any sherry until they have enough sherry influence to be used in whisky making.

There may be up to ten litres of sherry left in the cask. It simply soaks into the wood, which will have a huge impact on the flavour and colour of the whisky. The inside of the cask is usually kept slightly wet while it is being transferred. Other contributing factors are the number of fills and the type of oak used. The more fills, the less of those dried fruit and Christmas spice flavours you’ll get.

The whisky is often ‘finished’ in a sherry butt to allow just enough influence without making the sherry flavour overpowering.

Sherry casks (usually around 500 litres) are very popular, but are very expensive (up to 10 times the cost of a bourbon barrel), so many distilleries choose not to (or cannot afford to) use them on a regular basis. Casks used for all the main styles of sherry are used for ageing whisky, with the sweet Pedro Ximénez and rich oloroso the most common. Consider two sherried whiskies: a refill butt from Signatory of Clynelish 1995 and Lagavulin 1995 Distillers Edition, which is finished in Pedro Ximénez (PX) sherry casks. These add notes of chocolate, orange and dried fruits, with the smokiness of the Lagavulin adding an extra dimension.

Port

There are several types of port available and each has its unique style. Tawny port is golden in colour and is mainly aged in older wooden casks to allow gentle oxidation. While tawny port can be aged in oak for up to 40 years, vintage port only spends two to three years in the cask. Ruby port is mainly matured in steel tanks to avoid oxidation, therefore ex-ruby port wooden casks aren’t widely available. And when ruby port is aged in wood, the maturation time is kept short. Port can be aged in large port pipes or smaller port barriques.

The most common port casks used for whisky are those used to hold ruby port, although tawny or white are also used, the latter adding both richness and a refreshing dryness. Casks used for the red styles of port add notes of strawberry and raspberry. The Benriach 21 Year Old Tawny Port Finish shows wonderful balance between dry spicy flavours – clove and nutmeg – and red fruits.

Rum

A lesser-seen type (and very rarely seen for full maturation), rum casks add a whack of tropical fruit and lots of sweetness to whisky. Rum cask ageing has been fairly popular in recent years. No wonder, as these casks add yummy, sweet tropical notes into whisky and tend to be easily available. Rum casks are made from American oak. There are a wide range of rum styles, therefore each will have a unique influence on the spirit. Rum casks are used to ‘finish’ whisky before bottling, to allow just enough of those fruity and baking spice aromas. Rum-cask-finished whiskies also make a great addition to cocktail making.

The Glenfiddich 21 Year Old, finished for around four months, has proved a very popular release since its relaunch at the start of the decade, and with exceptional complexity and enticing notes of green apple, pear, mango, fudge and crème brûlée, it’s easy to see why.

Wine

Ex-wine casks are not generally as commercial as bourbon or sherry casks – Maturing whisky in wine casks is still a process that is being refined and developed. The market for it is still in its infancy, and while it may expand with time, the current market generally values ex-sherry and ex-bourbon casks much more highly – there are a few exceptions for specific distilleries. Some distilleries have a more established history of working with wine casks – Distilleries such as Bruichladdich and Glenmorangie have an established history of working with wine casks. Any distilleries with a proven history of working well with wine casks can command a competitive market value.

Wine casks vary from dry to sweet, with both red and white used. Sauternes casks add sweetness and notes honeyed fruit, whereas dry white wine, especially Chardonnay casks, will add butteriness and a mouth-coating texture. Due to the tannin in red wine, these casks impart dryness and fruity notes. The Glen Garioch 1998, aged for 15 years in red-Bordeaux casks, displays lovely integration between the red fruit (cherry and strawberry) and dry, earthy, smoke, with an underlying notes of grape.

Madeira

Whiskies matured in Madeira casks usually pick up the spice and fruitiness of the wine remaining in the staves. The effect on the taste also depends very much on the type of Madeira previously contained. The Malvasia grape is grown almost exclusively for Madeira production. It is very sweet and provides the special taste of Madeira.

The Estufagem barrel ageing production process is what makes Madeira Wine so special. It is a special heat and humidity treatment designed to simulate the climate during the voyage of the Madeira barrels on the ships of the 15th century. Both stainless steel tanks and oak barrels are used for ageing, and the law requires that the wine be kept at 55°C for at least 90 days. Through this heat treatment, the wine undergoes many reductive and oxidative phases and acquires its typical colour. After this ageing process, the alcohol content is raised by adding brandy.

A fortified wine from the eponymous island, these casks add extra spice and dark-fruit notes, along with dryness or sweetness depending on the style of Madeira. This year has seen a prominent release with the eighth edition of Glenmorangie’s Private Edition series: Bacalta, which is finished in sweet Malmsey Madeira casks.

Marsala

Marsala is an Italian fortified wine that comes from the town of Marsala in Sicily. The climate on the Mediterranean island is mild, with temperatures between 13° C and 29° C. The European Community has protected the name 'Marsala' for wine produced in Italy.

The biggest unique selling point of Marsala is the special ageing method, called 'perpetuum' by locals. This name comes from the (non-sparkling) wine that was previously produced in Sicily. In the perpetuum method, the barrels are never completely emptied. The barrels are filled with the latest harvest, left to mature and then bottled according to demand. When the next harvest is ready, the barrels are filled again. Thus, each Marsala wine is a combination of different vintages.

The difference between the local Perpetuum wine and Marsala is that Marsala is fortified with brandy - originally to make it durable for long sea voyages. Marsala has a sweet, complex and sometimes nutty taste. This also comes into play in whisky that has been aged in Marsala casks. The different Marsala wines have different colours, ranging from dark amber to light brown tones. The barrels used for whisky production previously contained mostly sweet, dark Marsala, so Marsala maturations or post-maturations are usually darker than normal whiskies.

Ongoing releases of Marsala-matured whiskies are rare. The limited-edition Ledaig 19 Year Old is a rich, fortified wine from Sicily which can be dry or sweet, in both cases adding extra complexity and extra spice.

New (Virgin) Oak

The purchase of a fresh Virgin Oak cask is a larger investment for a distillery than that of a used Bourbon, Sherry or wine cask.

Very seldom used for full maturation, as it imparts powerful, spicy flavours which can overwhelm the spirit, it is useful for finishing, where the extra toast can add a layer of complexity, especially to longer-aged whiskies. An example of this is the newly release Bladnoch Talia 25 Year Old. 

Long-term maturation in 2nd fill casks allows the magical interactive process to really play out without the additive process becoming over-bearing or upsetting the balance. Single malts matured from 15 to 25 years in 2nd fill casks produce some of the finest results.

New charred oak imparts a flood of colour and flavour that can give the initial impression that a spirit is older than it really is. Benromach Organic is aged in new oak and bottled between 5 and 6 years of age, but the whisky's colour resembles that of scotch aged in sherry casks for 12 years or more. The casks are highly active and the spirit matures quickly. They use virgin American oak casks, and as such you can pick out strong vanilla and toffee aromas. A spicy, peppery note develops through the freshness of the wood. 

The caramel, which is produced by toasting and burning out the barrel, gives the whisky its dark colour. We know this from American whiskey, which is very dark although it is usually only matured in the barrels for two to four years. The dark colour comes to the whiskeys from the cask alone. This is because a fresh barrel not only has more aromas to give off, but also more colour than a refilled one.

For this reason, Scotch whisky usually turns out much lighter when ex-bourbon casks are used. Much of the colour has already been transferred from the oak to the bourbon. Virgin oak casks, even when re-matured, result in a darker colour for Scotch whisky.

Before the whisky is matured in the cask, the cask is toasted and burnt out. During toasting, the cask is heated to at least 150°C. This causes the cellulose to split and break down into wood sugar, which begins to caramelise at these high temperatures. Only then does the cask release the familiar caramel, vanilla and coconut aromas into the whisky. During the subsequent burnout, you go directly into the cask with a large flame, which causes a dark layer of activated charcoal to form on the inner cask wall. This helps to filter out the pungent tastes and aromas from the whisky like an activated charcoal filter during cask maturation. During toasting and burning out, the distillery can vary the duration and thus depth of activation depending on the desired result.

On Islay, Bruichladdich Distillery first experimented with full virgin oak maturation in 2008 by filling 300-litre, medium-toasted new French oak casks with heavily peated new-make spirit, released in 2016 as Octomore 7.4. They got fantastic flavours developing very quickly in the spirit, although, because the casks have so much to give, they need to be watched very closely as they mature. The downside is that if one take his eyes off the casks for too long, they can end up with a whisky where the cask has dominated the spirit and it becomes overly oaked. While not for everyone, virgin oak casks are adding new dimension to Irish, Scotch, and even Indian whiskies, imparting wood-forward flavours that beckon like an old flame to fans of American whiskey.

Cognac

One of the rarer cask types, Cognac casks are made from French Limouisin oak and add aromatics and perfumed fruit, richness and subtle fruitiness to the whisky. Cognac casks tends to be very old as cognac can be aged up to 50 years. One example of this is Bruichladdich’s excellent Cuvée 640 Eroica.

Cognac barrels initially use new highly active French oak, which makes oak selection a critical aspect of each producer’s approach to the finished spirit. The most abundant oaks are the Pedunculate Oak (Quercus robur) and the Sessile Oak (Qeurcus pentraea). Hennessey extols Limousin oak for the “rich and creamy vanilla character” it imparts in their spirit, but Limousin is a forested region where both oaks grow, so that does not indicate a preference for either species.

Barrels are toasted and charred by naked flame at the cooperage. Barrels are reused, much like in Scotch, to provide blenders with various flavour profiles. “Futs-roux” is the term for refills. Cognac can be filled into casks which have had almost all the flavour removed from the wood, to allow for much greater ageing.

As with a whisky cask, the alcohol will act as a solvent to extract wood components such as tannins and vanillin from the staves. Cognac casks have been used occasionally in Scotch maturation over the last 50 years, including a Glenfarclas 43 year old, some interesting releases from Bruichladdich where Cognac casks have been used for peated and unpeated spirit, and Arran releases. It is becoming much more of a trendy proposition these days as the stuffy old world of Scotch begins to open up to a bit more experimentation. Cognac casks seem entirely pedestrian in the face of tequila and mezcal casks.

Cognac finished whiskies are appealing; it’s a traditional method of maturation harking back to the trading days between Scotland and France prior to the Union of the Crowns

Many other cask types are used for ageing whisky. Some of them work – the recently launched Glenfiddich Experimental Series IPA Cask was finished in beer casks, resulting in a floral and fruity whisky – and some should never be tried again.Caveat Emptor! 

        

Original Content	Category	Influence on Taste
Bourbon	Whiskey	Vanilla, sweetness, caramel
Amontillado	Sherry	Sweetness, nutty, dry, fresh, acidity
Fino	Sherry	Light fruit, sweetness, dryness, light wood
Manzanilla	Sherry	Salty, dryness, sea aromas, fresh, some fruit
Moscatel	Sherry	Very sweet, dark fruits, sultanas, syrup
Oloroso	Sherry	Deep, dark, nutty, dark ripe fruits
Palo Cortado	Sherry	Rich, sweet, dry, sweet spices, fruits
Pedro Ximénez (PX)	Sherry	Very sweet, dark fruits, sultanas, syrup
Port (sweet)	Port wine	Sweet, dried fruits, spiciness
Port (semi-dry)	Port wine	Slightly sweet, dried fruits, spiciness
Port (dry)	Port wine	Dry, dried fruits, spiciness
Ruby Port	Port wine	Very fruity, dark fruits, sweetness, dryness
Tawny Port	Port wine	Very fruity, nut, caramel, chocolate and tobacco
Madeira	Liqueur wine	Spiciness, light fruitiness, sweetness, dryness
Marsala	Liqueur wine	Sweet, complex, spices
Amarone	Red wine	Tannins (bitter), dry, sultanas, ripe fruits
Barolo	Red wine	Fruits, tannins (bitter), dried fruits, heavy aromas
Bordeaux	Red wine	Strong red fruits, grapes, berries
Chardonnay	White wine	Light, fresh, sour, tropical fruits
Muscat	White wine	Floral, sweet, citrus, peach
Sauternes	White wine	Sweet, lemon peel, acidity, light fruit
Tokay	White wine	Light fresh fruits (lemon, mango), very sweet
Burgundy	Wine	Very fruity, slightly sweet, slightly dry
Rum (white)	Spirit	Sweet, molasses, vanilla, tropical fruits, almond
Rum (dark)	Spirit	Sweet, syrup, dark fruits, oak caramel, vanilla
Beer	Beer	Hops, malt
Virgin Oak		Vanilla, cloves, caramel or tannins
Mizunara Oak	Ex Japan	Fruity, sweet

GRAIN SCOTCH WHISKY

 GRAIN SCOTCH WHISKY

INTRODUCTION

To the uninitiated, grain whiskies are the filler in blends, knitting together the real flavour from the single malts and – since they’re typically cheaper to make – keeping the price down. True, but only partially so. Apart from giving real flavour and texture to blends, well-made grain whiskies have a distinct character all their own.

Single malts get the headlines, but they almost certainly wouldn’t exist without grain whisky – essential to the creation of the blended Scotch brands which are the backbone of the industry. The vast majority of grain whisky goes into blends, but there are a small but growing number of specialist grain bottlings.

SINGLE GRAIN SCOTCH WHISKY

Single grain whisky is defined by its single distillery manufacturing process. A whisky must be made by a single distillery in order to qualify as a single grain whisky. Single grain, regardless of the name, can be composed of one or more grains – that may not be malted or unmalted barley, creating a light-bodied and mellow taste for whisky lovers to enjoy.

To be recognised as a single grain, a whisky must be made from a single grain or blend of grains at a single distillery. This technique can employ malted or unmalted grains, but it is not confined to that. A grain whisky employs additional malted or unmalted grains in the mash, rather than mostly malted barley. If a single grain whisky is classified as Scotch, it must be matured for at least three years as it happens with any other types of Scotch Whisky.

It is essential to remember that the term “single grain whisky” refers to the number of distilleries, not the number of grains that can be utilised. The laws do not specify the size or shape of the still. However, this type is commonly distilled in a column or Coffey still rather than a pot still.

To avoid using artificial enzymes, most distillers utilise at least 5% malted barley, which allows enough amounts of natural enzymes to be introduced, easing the fermentation process. In other words, grain whisky is made by cooking up unmalted cereal grains – corn, wheat or maize, but typically wheat these days – and then combining them with some malted barley to help kick-start fermentation.

Distillation is carried out using the continuous patent still process, a method pioneered and refined in the 19th century. Apart from the obvious efficiencies of this being a continuous process – in contrast to single malt distillation, which happens in batches – the aim here is produce a spirit high in alcohol and light in character. At cask-filler strength, it is not potable and requires  maturation in oak casks, no matter how old.

The rules governing Scotch whisky production stipulate that grain whisky must keep some flavour from its raw materials, and different grain distilleries – like their malt cousins – produce different styles. With practice, you can tell your Cameronbridge from your North British or your Girvan.

Bottlings from the big grain distilleries, which feed the vast blended Scotch whisky industry, have long been bottled and sold, mostly as curiosities to pique the interest of the whisky enthusiast. But things are changing.

Scotch whisky iconoclasts Compass Box’s blended grain whisky Hedonism (you can blend grains from different distilleries in a similar way to blended malts) has been a favourite for several years, while fellow blended grain Snow Grouse, unusually designed to be drunk cold, is a good introduction to the world of grain.

And now William Grant, owner of the Girvan grain distillery, has gone further by producing its own range of aged single grain whiskies, including an NAS bottling and a distinctly high-end 25-year-old. Exciting times – at last – for grain whisky.

The main feature of grain whisky distilleries is their large capacities with an average of over 50m Litres of Pure Alcohol (LPA) produced per year. In comparison, most malt distilleries are smaller with an average of circa 2.5m LPA produced per year. Scotch whisky production and marketing between the start of the Second World War (WWII) and the end of the last millennium changed and shaped the current modern whisky industry profoundly. Numerous changes took place over the past five decades, starting with WWII until the mid 1970s.

As a consequence of the WWII and the restrictions in distilling, the amount of proof gallons of malt whisky distilled decreased rapidly from 10.7 million in 1939 to nil in 1943 before increasing progressively to pre-war levels in 1949 and stabilising around 12 million between 1950 and 1954. The production volume for grain volume followed the same trends.

WWII & RESTRICTIONS:

In early 1940 the manufacture of spirits was limited to 1/3 of the quantities distilled in the year ended before September 30th. This was to ensure food supplies for the British population. Patent (grain) distillation virtually ceased in 1940. The malt distilleries were limited to 1/3 – 10%. In 1944, distilleries were allowed to resume production to 1/3 of the 1939 volumes.

In addition, to the reduction of production, several distilleries were bombed [e.g., Banff and Caledonian (Cally) distilleries] resulting in estimated losses of 4.5 millions proof gallons, the equivalent of 1 year of war production. 

Once the largest distillery in Scotland, Edinburgh's ‘Cally’ produced grain whisky from a Coffey still, as well as two large pot stills. Covering five acres of land, Caledonian was built during a boom in new grain distillery builds – by 1857 there were 17 distilleries operating patent stills in Scotland. The boom led to oversupply, but Cally rode the tide. The distillery also produced an Irish-style grain whisky distilled in two large pot stills, a style revered among blenders at the time for its consistency. It was shut down in the 80s.

Some old parcels of Caledonian have been bottled as a single grain by indie bottlers in recent years. It has never been bottled as a single grain, save for a commemorative bottling for the 1986 Commonwealth Games held in Edinburgh, while Diageo released a 40-year-old, 1974 vintage under ‘The Cally’ label, as part of its 2015 Special Releases.

POST WAR

While close to 50% of the whisky was consumed at home, the situation changed markedly afterwards. Great Britain was in need of money to pay for their loans accumulated during WWII. Therefore, they decided to increase duties at home, to reduce home consumption and to push the industry towards export. Once the taste of whisky was experienced in Europe by US soldiers through , the US became rapidly the major export market for Scotch whisky. In 1947, the percentage of home-consumed whisky was 45.3%, but dropped to 30.1% the next year and remained at ~ 25% until 1954, decreasing only slightly afterwards (down to 20% in the 1970s. Exports of whisky (Scotch and Irish) to USA increased from 2.8 million in 1947 to 7.1 million proof gallons in 1954. Volumes remained at the same levels at home, at around 8 million PG during this period. In 1970, the USA represented 42% of the world market for Scotch.

This “revolution” in whisky distribution was due to the rationing imposed by the Scotch Whisky Association between 1940 and ’45, before being phased in gradually up to 1953. Restrictions were lifted on 1st January, 1954. During the post-war period, USA was by far the major export destination for Scotch, with Europe showing promise. Europe remained a complicated and challenging market, since each country had its own restrictions.

As a consequence of the WWII and the restrictions in distilling, the amount of PG of malt whisky distilled decreased rapidly from 10.7 million in 1939 to nil in 1943 before increasing progressively to pre-war levels in 1949 and stabilising around 12 million between 1950 and 1954. The production volume for grain volume followed the same trends. This led to an insufficiency of fully matured whisky to meet demand. 

Construction of new distilleries took place mainly in the 1960s, with Invergordon and Girvan distilleries featuring prominently. A consequence of increased output was a shortage of sherry casks. More American casks were thus imported. However, the construction of warehouses lagged behind. Both to save casks and warehouse space, grain whiskies began to be filled at 20° over proof instead of 11°, thus allowing to increase storage capacity of 8%.

DIFFERENCES BETWEEN MALT AND GRAIN WHISKY

As with single malt whisky, the word “single” in the name indicates that it is also the product of a single distillery. However, and here’s the main difference between them: single grain does not have to be exclusively manufactured from barley or malted. On the other hand, single grain whiskies are frequently manufactured from wheat, maize, or a combination of the two.

MAP OF GRAIN DISTILLERIES IN SCOTLAND

 

 

Cameronbridge, owned by Diageo, is the oldest (1824) and largest grain whisky distillery producing over 110m LPA per year. It was also known as Haig Distillery in the past. As part of their production expansion at this site, Diageo closed their Port Dundas grain distillery in Glasgow in 2010.

North British, a joint venture between Diageo and The Edrington Group, was established in 1885 and until a few years ago it used to be the 2nd largest grain whisky distillery producing around 72m LPA per year. It historically only used maize as the main cereal.

Girvan, owned by William Grant & Sons, was built in 1963 and it also produces malt whisky at its nearby Ailsa Bay distillery (2007). Since 2007, it has increased its production capacity by 50m LPA, and it is now the 2nd largest and comparable to Cameronbridge, producing over 100m LPA.

Invergordon, owned by Whyte & Mackay, a subsidiary of Emperador, is the most northernly located grain whisky distillery in Scotland. Founded around 1959 and producing 40m LPA per year.

Starlaw, owned by La Martiniquaise is the newest grain distillery, founded in 2010. It produces 25m LPA per year.

Strathclyde, owned by Pernod Ricard, was established in 1927 and produces around 40m LPA per year.

Loch Lomond, owned by the Loch Lomond Group, is the smallest grain whisky distillery producing around 18 LOA per year and it was introduced to the site in 1994. The Loch Lomond distillery also produces malt whisky and until the opening of Ailsa Bay in Girvan, it was unique in producing both grain and malt whisky on the same location in Scotland. One unusual feature is that one of the stills used at Loch Lomond Distillery (graphically represented below) is a Coffey/ Continuous still, with copper on the inside and producing Scotch whisky only with malted barley. This would be a single malt if it was not for the continuous distillation on process, rather than batch, and therefore it is called a single grain scotch whisky. The product is called Loch Lomond Single Grain Scotch whisky

To be known as ‘Scotch whisky’, a mash of cereals, water and yeast must be distilled and matured in Scotland for a minimum of three years in oak casks.

There are two main types of whisky produced in Scotland: malt whisky and grain whisky. All whisky begins its life as the product of a ‘single’ distillery – so these products are known as ‘Single Malt’ or ‘Single Grain’. No second or sister distillery may feature in this Single category.

Single malt whisky is made in a traditional batch process using a copper pot still. According to the Scotch Whisky Regulations 2009, to be classifed as a Single Malt Scotch Whisky it must be "produced from only water and malted barley at a single distillery by batch distillation in pot stills".

Single malt is the premium, traditional style of whisky, but the artisanal manner of its production is not easily scaled.

The production of single grain whisky is very different. Unlike single malt, it can be produced from a variety of different grains or cereal types, either malted or unmalted. Single grain whisky is also made continuously via a modern column still, on an industrial scale. The output is purer in alcohol, but with much less flavour and character than a single malt. It is also very much easier to produce.

The overwhelming majority of Scotch whisky consists of malt and grain whiskies mixed together to make a product known as Blended Scotch whisky. Blends have dominated the Scotch industry for over a century, and continue to do so today. In 2020, Blended Scotch whisky accounted for 62% of exports by value and 83% by volume. While bottled single malt Scotch is a rapidly growing category, it still falls behind, accounting last year for only 15% by volume and 36% by value of all Scotch whisky shipped overseas.

By law, the age statement shown on a Scotch must refer only to the youngest whisky included in the product – meaning that all malt and grain whiskies included must be at least as old as the age shown on the bottle.

Most Scotch is bottled between the ages of 3 and 12 years. Three years is the minimum age for a spirit to be classified as 'Scotch whisky', and many ‘value’ products, such as supermarket own-label blends, will likely consist of whisky at this age. At the same time, Johnnie Walker Black Label and the youngest Chivas Regal, which account for 10% of all Scotch sales worldwide, are both 12 year old whiskies.

The most important fact about malt and grain whisky is that they are both components of the same finished product – blended Scotch. As commodities, however, there are a few differences between malt and grain which are worth considering.

More grain whisky is produced than malt – but far fewer distilleries make it. The radically different methods used to produce malt and grain whisky mean that there are huge differences in the production capacity of the distilleries which make them.

There are currently 130+ active malt distilleries, and 7 active grain distilleries. The largest malt distillery, Glenfiddich, can produce 21m Litre of Pure Alcohol (LPA) per annum, while the smallest, Dornoch, can only make 0.02m LPA in one year.

These figures are dwarfed by those of grain distilleries. The largest grain distillery, Cameronbridge, can produce up to 110m LPA of whisky each year. Even the smallest grain distillery, Loch Lomond, produces 18m LPA – almost as much as the largest malt distillery, Glenfiddich.

Despite the fact that there are ~ 19 malt distilleries for every grain distillery, Scotland normally produces more grain whisky every year. The price of grain whisky is generally more homogenous than malt

For both new malt and new grain spirit, the distiller's selling costs are historically far more closely related to the costs of utilities and grain required for production than the selling prices of the finished product.

Grain whisky is far cheaper to produce than malt whisky. Historically, the price of new make malt spirit has been more than twice that of grain spirit, per LPA. (These prices do not include the cost of wood.)

Due to the low number of grain distilleries, it is easier to manage the production of grain whisky than malt whisky. In periods of over-production, the taps are, quite literally, turned off, or else, diverted as ethanol to mainstream industries, mainly pharma.

This is more difficult with malt whisky, due to the higher number of distilleries – and distillery owners. In the early 1980s, this caused a delayed reaction to slowing worldwide demand for Scotch, which was ultimately only resolved by a raft of malt distillery closures.

Today, however, two producers – Diageo and Chivas Brothers – own distilleries with a total capacity of 187m LPA – nearly half of the total full capacity of 395m LPA in Scotland. Distillers have also become better at forecasting future demand levels. This has reduced the danger of high-level over-production, like that of the 1980s, re-occurring.

More grain is used in blends than malt – and often at a younger age. In a blend, grain provides the bulk of the body of a blend, while malt provides the more complex flavours. For this reason, malt whisky used in a blend is often older than the grain used. The typical bottle of blended whisky is 70% grain, 30% malt. More premium offerings may include a higher percentage of malt.

As few distilleries produce grain whisky, and as the spirit which they all produce is relatively homogenous, there has not historically been a significant variance in the price of grain whisky at the same age from different distilleries. This is not the case for malt, where prices for whisky from different distilleries may vary more widely.

SINGLE GRAIN WHISKY TASTE

Single grain whiskies are often light-bodied and mellow, making them an excellent introduction for those who just now entering the whisky world. Corn, maize, wheat, and old barrels are commonly utilised. Add in oak maturation, typically in first-fill former Bourbon casks, and you have a gentle, often fruity and sweet whisky which at its best acquires a refined, velvety character as it ages.

Since this type of whisky is made from corn, maize, wheat and aged in older barrels, their character is somewhat sweeter than single malts, for instance. Contrarily to the bourbon flavour – that is made with 51% corn within the mash – the single grain expressions do not have the smoky flavours, the maple or vanilla flavours one can find in conventional bourbon whiskey.

THE GRAIN WHISKY MARKET

Historically, the single grain whisky category was not something that was bottled and marketed. It was and still is predominantly utilised in the production of blended whiskeys such as Dewar’s White Label, Johnnie Walker Red, and Jameson, to mention a few.

It is easier and less expensive to make than single malt, which is made in batches. Single grains can create a high-quality blended whisky at a very reasonable price when mixed with single malts. Historically, the single grain whisky category was not something that was bottled and marketed. It was and still is predominantly utilised in the production of blended whiskies such as Dewar’s White Label, Johnnie Walker Red, and Jameson, to mention a few.

It is easier and less expensive to make than single malt, which is made in batches. Single grains can create a high-quality blended whisky at a very reasonable price when mixed with single malts. The single grain category has gained popularity in recent years, with whisky companies producing some  excellent whisky expressions. 

If I were to be asked to nominate one single grain whisky, I'd go beyond the scope of this article for the Japanese Chita. I found it superior to all Scotch Grain whiskies. C'est vrai.