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Whiskey or Whisky is a type of distilled alcoholic beverage made from fermented grain mash. Various grains (which may be malted) are used or different varieties, including barley, corn, rye, and wheat. Whiskey is typically aged in wooden casks, typically made of charred white oak. Uncharred white oak casks previously used for sherry aging are also sometimes used.

Whiskey is a strictly regulated spirit worldwide with many classes and types. The typical unifying characteristics of the different styles and types are the fermentation of grains, distillation, and aging in wooden barrels.

Etymology
The word Whiskey (or Whisky) is an anglicization of the Classical Gaelic word uisce (or uisge) meaning "Water". This Gaelic word shared its ultimate origin with Germanic water and Slavic voda of the same meaning. Distilled alcohol was known in Latin as aqua vitae ("water of life"). This was translated into Old Irish as uisce beatha.

Names and spellings: Much is made of the word's two spellings; whisky and whiskey. There are two schools of thought. One is that the spelling difference is simply a matter of regional language convention for the spelling of a word, an indication that the spelling varies depending on the intended audience of background or personal preferences of the writer (like the difference between color and colour), and the other is that the spelling should depend on the style or origin of the spirit being described. There is general agreement that when quoting the proper name, printed on the label, the spelling on the label should not be altered.

The spelling "whiskey" is common in Ireland and the United States, while whisky is used in all other whisky-producing countries. In the US, the usage has not been always consistent. From the late eighteenth century to the mid-twentieth century, American writers used both spellings interchangeably until the introduction of newspaper style guides.

Since the 1960s, American writers have increasingly used whiskey as the accepted spelling for aged grain spirits made in the US and whisky for aged grain spirits made outside the US. However, some prominent American brands, such as George Dickel, Maker's Mark, and Od=ld Forester (all made by different companies), use the whiskey spelling on their labels, and the Standards of Identity for Distilled Spirits, the legal regulations for spirit in the US, also known as the whisky spelling throughout.

Within Scotland, the whiskey made in Scotland is simply called whisky, while outside Scotland (and in the UK regulations that govern its production) it is commonly called Scotch Whiskey, or simply "Scotch" (especially in North America).

History
Early Distilling
It is possible that distillation was practiced by the Babylonians in Mesopotamia in the 2nd millennium BC, with perfumes and aromatics being distilled, but this is subject to uncertain and disputed interpretations of the evidence.

The earliest certain chemical distillations were by Greeks in Alexandria in the 1st 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.

Ireland and Scotland
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", 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 Barber-Surgeons.^[17] The earliest mention of whisky in Ireland comes from the seventeenth-century Annals of Clonmacnoise, which attributes the death of a chieftain in 1405 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 1495 where malt is sent "To Friar John Cor, by order of the king, to make aqua vitae", 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 Barber-Surgeons, 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 to 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 royal license to distill Irish whiskey from 1608, the Old Bushmills Distillery in Northern Ireland is the oldest licensed whiskey distillery in the world.

18th Century
In 1707, the Acts of Union merged England and Scotland, and thereafter taxes on it rose dramatically. Following parliament's divisive 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 or revenuers. 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; George Washington operated a large distillery at Mount Vernon. Given the distances and primitive transportation network of colonial America, farmers often found it easier and more profitable to convert corn to whisky and transport it to market in that form. It also was a highly coveted sundry and when an additional excise tax was levied against it in 1791, the Whiskey Rebellion erupted.

19th Century

The drinking of Scotch whisky was introduced to India in the nineteenth century. The first distillery in India was built by Edward Dyer at Kasauli in the late 1820s. The operation was soon shifted to nearby Solan (close to the British summer capital Shimla), as there was an abundant supply of fresh spring water there.

In 1823, the UK passed the Excise Act, legalizing 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 a 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.

20th Century
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 whiskey 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 are 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 vapor enriched to 40–60% alcohol, a column still can achieve a vapor alcohol content of 95.6%; 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.

While aging in wooden casks, especially American oak, and French oak casks, whisky undergoes six processes that contribute to its final flavor: extraction, evaporation, oxidation, concentration, filtration, and colouration. Extraction in particular results in whisky acquiring a number of compounds, including aldehydes and acids such as vanillin, vanillic acid, and syringaldehyde. The casks used for aging bourbon whiskey are required to be new (and charred); after being used for this purpose, these casks are typically exported for use in the aging of other whiskies elsewhere. Distillers will sometimes age their whiskey in barrels previously used to age other spirits, such as rum or sherry, to impart particular flavors.

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.

Types of Whiskey

Whisky or whisky-like products are produced in most grain-growing areas. They differ in the base product, alcoholic content, and quality.

• Malt whisky – made primarily from malted barley
• Grain whisky – made from any type of grain

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 recognizable 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 whisky is labeled "pure malt" or just "malt" it is almost certainly 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 flavor 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 the single-barrel) whiskies are bottled from an individual cask, and often the bottles are labeled with specific barrel and bottle numbers. The taste of these whiskies may vary substantially from cask to cask within a brand.

American Whiskey

American whiskey is distilled from a fermented mash of cereal grain. It must have the taste, aroma, and other characteristics commonly attributed to whiskey.

Some types of whiskey listed in the United States federal regulations are:

• Bourbon whiskey: made from mash that consists of at least 51% corn (maize) and aged in new charred oak barrels.
• Corn whiskey: made from mash that consists of at least 80% corn and is not aged, or, if aged, is aged in uncharred or used barrels.
• Malt whiskey: made from mash that consists of at least 51% malted barley
• Rye whiskey: made from mash that consists of at least 51% rye
• Rye malt whiskey: made from mash that consists of at least 51% malted rye
• Wheat whiskey: made from mash that consists of at least 51% wheat

These types of American whiskey must be distilled to no more than 80% alcohol by volume and barrelled at no more than 125 proof. Only water may be added to the final product; the addition of coloring or flavoring is prohibited. These whiskeys must be aged in new charred-oak containers, except for corn whiskey, which does not have to be aged. If it is aged, it must be in uncharred oak barrels or in used barrels. Corn whiskey is usually unaged and sold as a legal version of moonshine.

There is no minimum aging period required for a spirit to legally be called whiskey. If one of these whiskey types reaches two years of aging or beyond, it is additionally designated as straight, e.g., straight rye whiskey. A whiskey that fulfills all the above requirements but derives from less than 51% of any one specific grain can be called simply a straight whiskey without naming a grain.

US regulations recognize other whiskey categories, including:

• Blended whiskey: a mixture that contains a blend of straight whiskeys and neutral grain spirits (NGS), and may also contain flavorings and colorings. The percentage of NGS must be disclosed on the label and may be as much as 80% on a proof gallon basis.
• Light whiskey: produced in the US at more than 80% alcohol by volume and stored in used or uncharred new oak containers
• Spirit whiskey: a mixture of neutral spirits and at least 5% of certain stricter categories of whiskey

Another important labeling in the marketplace is Tennessee whiskey, which includes brands such as Jack Daniel's, George Dickel, Collier and McKeel, and Benjamin Prichard's. The main difference defining a Tennessee whiskey is that it must be filtered through sugar maple charcoal before aging, known as the Lincoln County Process. (Benjamin Prichard's, which is not so filtered, was grandfathered in when the requirement was introduced in 2017.) The rest of the distillation process of Tennessee Whiskey is identical to bourbon whiskey. Whiskey sold as "Tennessee whiskey" is defined as bourbon under NAFTA and at least one other international trade agreement and is similarly required to meet the legal definition of bourbon under Canadian law.