History / Background
Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Different grains are used for different varieties, including barley, malted barley, rye, malted rye, wheat, buckwheat and corn. Whisky is typically aged in wooden casks, made generally of charred white oak.
Whisky is a strictly regulated spirit worldwide with many classes and types. The typical unifying characteristics of the different classes and types are the fermentation of grains, distillation, and aging in wooden barrels.
Background
It is possible that distillation was practised by the Babylonians in Mesopotamia in the 2nd millennium BC, with perfumes and aromatics being distilled but this is subject to uncertain and disputable interpretation of evidence. The earliest certain chemical distillations were by Greeks in Alexandria in about the 3rd century (AD), but these were not distillations of alcohol. The medieval Arabs adopted the distillation technique of the Alexandrian Greeks, and written records in Arabic begin in the 9th century, but again these were not distillations of alcohol. Distilling technology passed from the medieval Arabs to the medieval Latins, with the earliest records in Latin in the early 12th century. The earliest records of the distillation of alcohol are in Italy in the 13th century, where alcohol was distilled from wine. An early description of the technique was given by Ramon Llull (1232 – 1315). Its use spread through medieval monasteries, largely for medicinal purposes, such as the treatment of colic and smallpox.
The art of distillation spread to Ireland and Scotland no later than the 15th century, as did the common European practice of distilling ‘Aqua Vitae’ or spirit alcohol primarily for medicinal purposes. The practice of medicinal distillation eventually passed from a monastic setting to the secular via professional medical practitioners of the time, The Guild of Surgeon Barbers. The first confirmed written record of whisky comes from 1405 in Ireland. In the Irish Annals of Clonmacnoise in 1405, the first written record of whisky attributes the death of a chieftain to "taking a surfeit of aqua vitae" at Christmas. In Scotland, the first evidence of whisky production comes from an entry in the Exchequer Rolls for 1494 where malt is sent "To Friar John Cor, by order of the king, to make aquavitae", enough to make about 500 bottles.
James IV of Scotland (r. 1488–1513) reportedly had a great liking for Scotch whisky, and in 1506 the town of Dundee purchased a large amount of whisky from the Guild of Surgeon Barbers, which held the monopoly on production at the time. Between 1536 and 1541, King Henry VIII of England dissolved the monasteries, sending their monks out into the general public. Whisky production moved out of a monastic setting and into personal homes and farms as newly independent monks needed to find a way to earn money for themselves.
The distillation process was still in its infancy; whisky itself was not allowed to age, and as a result tasted very raw and brutal compared to today’s versions. Renaissance-era whisky was also very potent and not diluted. Over time whisky evolved into a much smoother drink.
With a licence to distil Irish whiskey from 1608, the Old Bushmills Distillery in the north coast of Ireland is the oldest licenced whiskey distillery in the world.
In 1707, the Acts of Union merged England and Scotland, and thereafter taxes on it rose dramatically.
After the English Malt Tax of 1725, most of Scotland’s distillation was either shut down or forced underground. Scotch whisky was hidden under altars, in coffins, and in any available space to avoid the governmental Excisemen. Scottish distillers, operating out of homemade stills, took to distilling whisky at night when the darkness hid the smoke from the stills. For this reason, the drink became known as moonshine. At one point, it was estimated that over half of Scotland’s whisky output was illegal.
In America, whisky was used as currency during the American Revolution. It also was a highly coveted sundry and when an additional excise tax was levied against it, the Whiskey Rebellion erupted in 1791.
In 1823, the UK passed the Excise Act, legalizing the distillation (for a fee), and this put a practical end to the large-scale production of Scottish moonshine.
In 1831, Aeneas Coffey patented the Coffey still, allowing for cheaper and more efficient distillation of whisky. In 1850, Andrew Usher began producing a blended whisky that mixed traditional pot still whisky with that from the new Coffey still. The new distillation method was scoffed at by some Irish distillers, who clung to their traditional pot stills. Many Irish contended that the new product was, in fact, not whisky at all.
By the 1880s, the French brandy industry was devastated by the phylloxera pest that ruined much of the grape crop; as a result, whisky became the primary liquor in many markets.
During the Prohibition era in the United States lasting from 1920 to 1933, all alcohol sales were banned in the country. The federal government made an exemption for whisky prescribed by a doctor and sold through licensed pharmacies. During this time, the Walgreens pharmacy chain grew from 20 retail stores to almost 400.
Production
Distillation
A still for making whisky is usually made of copper, since it removes sulfur-based compounds from the alcohol that would make it unpleasant to drink. Modern stills are made of stainless steel with copper innards (piping, for example, will be lined with copper along with copper plate inlays along still walls). The simplest standard distillation apparatus is commonly known as a pot still, consisting of a single heated chamber and a vessel to collect purified alcohol.
Column stills are frequently used in the production of grain whisky and is the most commonly used type of still in the production of Bourbon and other American whiskeys. Column stills behave like a series of single pot stills, formed in a long vertical tube. Whereas a single pot still charged with wine might yield a vapour enriched to 40-50% alcohol, a column still can achieve a vapour alcohol content of 96%; an azeotropic mixture of alcohol and water.
Aging
Whiskies do not mature in the bottle, only in the cask, so the "age" of a whisky is only the time between distillation and bottling. This reflects how much the cask has interacted with the whisky, changing its chemical makeup and taste. Whiskies that have been bottled for many years may have a rarity value, but are not "older" and not necessarily "better" than a more recent whisky that matured in wood for a similar time. After a decade or two, additional aging in a barrel does not necessarily improve a whisky.
Packaging
Most whiskies are sold at or near an alcoholic strength of 40% abv, which is the statutory minimum in some countries – although the strength can vary, and cask-strength whisky may have as much as twice that alcohol percentage.
Exports
Whisky is probably the best known of Scotland's manufactured products. Exports have increased by 87% in the past decade and it contributes over £4.25 billion to the UK economy, making up a quarter of all its food and drink revenues. In 2012, the US was the largest market for Scotch whisky (£655 million), followed by France (£535 million). It is also one of the UK's overall top five manufacturing export earners and it supports around 35,000 jobs. Principal whisky producing areas include Speyside and the Isle of Islay, where there are eight distilleries providing a major source of employment. In many places, the industry is closely linked to tourism, with many distilleries also functioning as attractions worth £30 million GVA each year.
In 2011, 70 per cent of Canadian whisky was exported, with about 60 per cent going to the US, and the rest to Europe and Asia. 15 million cases of Canadian whisky were sold in the US in 2011.
Types
Whisky or whisky-like products are produced in most grain-growing areas. They differ in base product, alcoholic content, and quality.
- Malt whisky is made primarily from malted barley.
- Grain whisky is made from any type of grains.
Malts and grains are combined in various ways:
- Single malt whisky is whisky from a single distillery made from a mash that uses only one particular malted grain. Unless the whisky is described as single-cask, it contains whisky from many casks, and different years, so the blender can achieve a taste recognisable as typical of the distillery. In most cases, single malts bear the name of the distillery, with an age statement and perhaps some indication of some special treatments such as maturation in a port wine cask.
- Blended malt whisky is a mixture of single malt whiskies from different distilleries. If a whisky is labelled "pure malt" or just "malt" it is almost certain a blended malt whisky. This was formerly called a "vatted malt" whisky.
- Blended whisky is made from a mixture of different types of whisky. A blend may contain whisky from many distilleries so that the blender can produce a flavour consistent with the brand. The brand name may, therefore, omit the name of a distillery. Most Scotch, Irish and Canadian whisky is sold as part of a blend, even when the spirits are the product of one distillery, as is common in Canada.
- American blended whisky may contain neutral spirits.
- Cask strength (also known as barrel proof) whiskies are rare, and usually only the very best whiskies are bottled in this way. They are bottled from the cask undiluted or only lightly diluted.
- Single cask (also known as single barrel) whiskies are bottled from an individual cask, and often the bottles are labelled with specific barrel and bottle numbers. The taste of these whiskies may vary substantially from cask to cask within a brand.
Chemistry
Whiskies and other distilled beverages, such as cognac, and rum are complex beverages that contain a vast range of flavouring compounds, of which some 200 to 300 are easily detected by chemical analysis. The flavouring chemicals include "carbonyl compounds, alcohols, carboxylic acids and their esters, nitrogen- and sulphur-containing compounds, tannins and other polyphenolic compounds, terpenes, and oxygen-containing heterocyclic compounds" and esters of fatty acids. The nitrogen compounds include pyridines, picolines and pyrazines.
Flavours from distillation
The flavouring of whisky is partially determined by the presence of congeners and fusel oils. Fusel oils are higher alcohols than ethanol, are mildly toxic, and have a strong, disagreeable smell and taste. An excess of fusel oils in whisky is considered a defect. A variety of methods are employed in the distillation process to remove unwanted fusel oils. Traditionally, American distillers focused on secondary filtration using charcoal, gravel, sand, or linen to remove undesired distillates.
Canadian distillers traditionally employ column stills, which can be controlled to produce an almost pure (and less flavourful) ethanol known as neutral grain spirit or grain neutral spirit (GNS). Flavour is restored by blending the neutral grain spirits with flavouring whiskies.
Acetals are rapidly formed in distillates and a great many are found in distilled beverages, the most prominent being acetaldehyde diethyl acetal (1,1-diethoxyethane). Among whiskies the highest levels are associated with malt whisky. This acetal is a principal flavour compound in sherry, and contributes fruitiness to the aroma.
The diketone diacetyl (2,3-butanedione) has a buttery aroma and is present in almost all distilled beverages. Whiskies and cognacs typically contain more of this than vodkas, but significantly less than rums or brandies.
Flavours from oak
Whisky that has been aged in oak barrels absorbs substances from the wood. One of these is cis-3-methyl-4-octanolide, known as the "whisky lactone" or "quercus lactone", a compound with a strong coconut aroma.
Commercially charred oaks are rich in phenolic compounds. One study identified 40 different phenolic compounds. The coumarin scopoletin is present in whisky, with the highest level reported in Bourbon whiskey.
Flavours and colouring from additives
Depending on the local regulations, additional flavourings and colouring compounds may be added to the whisky. Canadian whisky may contain caramel and flavouring in addition to the distilled mash spirits. Scotch whisky may contain added (E150A) caramel colouring, but no other additives. The addition of flavourings is not allowed in American "straight" whiskey, but is allowed in American blends.
Chill filtration
Whisky is often "chill filtered": chilled to precipitate out fatty acid esters and then filtered to remove them. Most whiskies are bottled this way, unless specified as unchillfiltered or non chill filtered. This is done primarily for cosmetic reasons. Unchillfiltered whiskeys often turn cloudy when stored at cool temperatures or when cool water is added to them, and this is perfectly normal.
Types of Whisky
SINGLE MALT WHISKY
A single malt whisky is a whisky from a single distillery made using 100% malted barley. Scotch malt whisky must be matured for a legal minimum of 3 years. It must also be produced and matured in oak casks in Scotland. Generally single malt whiskies are divided into five main regions as follows:
LOWLAND MALT WHISKY
The Lowland region lies south of an imaginary line drawn from the Clyde estuary, on the west coast, to the Tay estuary, on the east coast. Whiskies from Lowland distilleries tend to be much SOFTER and LIGHTER in character. They often display very MALTY, GRASSY characteristics and more SUBTLE DELICATE AROMAS than whiskies from the other regions.
HIGHLAND MALT WHISKY
The Highland region includes most of the rest of mainland Scotland, hence a wide variety of characteristics can be found in Highland Malt Whiskies. Its whiskies will range from DRY and HEATHERY to SWEET and FRUITY - some even have a touch of SMOKE due to their proximity to the west coast.
SPEYSIDE MALT WHISKY
Technically Speyside lies within the Highland region, but it is home to approximately half of Scotland's malt whisky distilleries. This small area of land located to the north west of Aberdeen produces MELLOW, SWEET, MALTY and particularly FRUITY malt whiskies.
ISLAND MALT WHISKY
The islands stretch from the Orkney Islands, located off the north coast of Scotland, all the way down the west coast, encompassing Skye, Jura, Mull, Arran and Islay. The islands, in general, produce some of the more ROBUST whiskies with coastal influences SALTY TANG, FRESH SEA AIR - however, it is more specifically Islay that produces the heavy PEATY, SMOKY tasting malts in particular the distilleries located on the south coast of Islay.
CAMPBELTOWN MALT WHISKY
Campbeltown was probably the home of the first distilleries in Scotland, but now only two remain. Whisky from this area traditionally has a SMOKY style.
GRAIN WHISKY
Grain whisky is made from wheat and/or maize, a small amount of malted barley, water and yeast. It is produced in a Coffey Still instead of a Pot Still and tends to be much lighter and milder than malt whiskies. Grain whisky is used as the major componenet of blended whiskies. See below.
BLENDED WHISKY
A whisky which contains a mixture of both malt and grain whiskies. On a bottle of blended whisky you will sometimes see an age statement. This refers to the youngest whisky within the blend's composition. Aged blends are generally known as deluxe or premium blends and will be priced on a par with some of the malts. Deluxe or premium blends will normally contain a higher percentage of malt whisky than standard blends.
BLENDED MALT WHISKY
A mixture of malt whiskies from different single malt distilleries. This may also be referred to as pure malt whisky.
WHISKY LIQUEURS
With a Scotch whisky base the majority of whisky liqueurs are made using a blend of honey and mild herbs and spices. Cream is added to produce the whisky cream liqueurs.
CASK STRENGTH WHISKY
A whisky which has been taken straight from the cask and bottled without reduction with water - usually between 50-62% alcohol by volume.
The making of Whisky
Ingredients
The main ingredients used in making whisky form a short list:
Water -
Most of Scotland's water is very soft. Soft water will absorb more from the malted barley used to make whisky, than hard water will, which might offer a reason as to why it seems to make a suitable ingredient for whisky. Some also believe that peaty water will have an influence on the whisky, helping to give a peaty flavour to the drink. Otherwise the different waters used by distilleries should not affect the finished product too much. The most important factor for the distillery is that they have a large supply of water.
Malt -
Malted barley, or malt, is always used for malt whisky, not surprisingly. In contrast, grain whiskies will use maize or other cereals. Malt is explained in more detail below.
Yeast -
One of the less significant factors when it comes to the flavour of the whisky, but nevertheless a crucial element as the yeast is used to trigger the chemical process that converts sugars in the malted barley into alcohol.
Peat -
Peat is basically decayed vegetation that has not broken down in the soil due to poor drainage in the land. Cut from marshland bogs, it is used as fuel and in the case of whisky, as a fuel for halting the maturation process of the barley once it has begun to germinate. It adds a smoky flavour to whisky which is usually associated with the Island malts, particularly Islay whiskies, but is present in virtually all malts in varying degrees.
The Process -
Malting
Once the barley has arrived at the distillery it is steeped in water to allow the germination process to begin. Shoots begin to grow from the grains of barley as a result. Before the germination can go too far and the barley grain begins to consume its own sugar in order to grow, it is heated to halt the process, by kilning the barley. It is at this stage that peat is used to introduce its flavour to greatest effect. Peat was traditionally the fuel used for drying and slightly cooking the malted barley in many parts of Scotland and is still used for the flavours it imparts.
Depending on whether a distillery is using traditional floor maltings where the germinating barley is spread thinly on the floor, or a more modern system such as a rotary drum which allows the barley to be aired and heated more uniformly, the malting process can take between 20 and 48 hours. From here the malt will be ground down, or milled, ready for mashing.
Mashing
Warm water is added to the milled, malted barley which is then fed into a large, circular vessel called a mash-tun to allow the mashing to take place. Mashing is the stage where the starches in the barley convert to sugars which will later be fermented into alcohol. The mash-tun will contain either mechanical rakes or rotating blades that stir the mash. Slots in the base of the mash-tun allow the now sugary liquid, called ‘wort’, to run off. The wort will be recycled through the mash-tun three or four times before moving onto to be allowed to ferment.
Fermentation
By this stage the liquid is ready for fermentation. In a wash-back the wort has yeast added to it to encourage the chemical reaction that converts the sugars to alcohol. Washbacks were traditionally made of wood, although some distilleries now use stainless steel. While more time consuming to clean out and less sterile, it is reckoned by some distillery managers that using wooden vessels does add to the flavour of the whisky.
Distillation
Scottish whisky distilleries use pot-stills to distill the spirit that will become whisky. Pot-stills, the copper icons of the whisky industry, offer a means of evaporating the alcohol, which turns to vapour before water does, which is then condensed and collected after escaping through the neck of the still. The exact shape of the still, its height, the shape and length of the neck, the fact that the still is made from copper rather than another metal, all play their part in making each whisky individual. The use of copper in making stills is crucial, as it’s only this metal that will remove some of the unwanted elements from the spirit – experiments with stainless steel have proved the importance of the metal used in the still. The liquid will typically be distilled twice, first in a larger ‘wash’ still, then in a ‘low wines’ or ‘spirit’ still in order to collect the ‘heart of the run’, the batch of spirit that the stillman knows will be suitable for maturing as whisky.
Maturation
Scotch whisky is always matured in oak casks. The exact type of wood used in the maturation stage and what the cask has been used for prior to being filled with whisky lends a great deal to the final flavour of the whisky when it is bottled. Oak is sourced from America and Spain – the right choice of oak being crucial. New oak is never used for maturing whisky as the wood will lend too much flavour to the spirit. For the majority of whiskies, casks that have been used for maturing bourbon are used. American law prevents bourbon producers from using casks twice, so after being used, a cask is of little use to the bourbon industry. The Scotch whisky industry benefits from this, with the practice guaranteeing a steady supply of ex-bourbon casks. Some distillers will use ex-sherry casks from Spain instead, perhaps the most famous being The Macallan, which uses ex-oloroso sherry casks.
While some whiskies spend their whole lives in the cask they were first poured into, some distilleries will use a second stage of maturation to add a different edge to the whisky. Glenmorange are one of the bigger producers of whisky that have done just this with their range of malts, which have Madeira, Port and Sherry finishes achieved by a maturation in a second barrel. Recent limited edition bottlings have also seen Malaga, Fino Sherry, Cognac, Bordeaux, Cote de Nuits finishes.
Just how long the whisky will mature before it is bottled is another complex question. Three years is the legal minimum but most will spend much longer, depending partly on how quickly the whisky 'grows up' which will vary from one whisky to the next. Over time, flavours from the environment that the distillery is in such as salty seaside air may offer its own particular effects. Some whisky will also be lost gradually through time as a very slow evaporation occurs through the pores of the wooden cask. Seeping out at a rate of roughly 1-2% a year, this loss is known as the 'angels share.' When the distillery sees fit, the whisky will be bottled.
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