Different grains are used for different varieties, including: barley, malted barley, rye, malted rye, wheat, and maize (corn). Whisky derives from the Gaelic word for "water" (uisce or uisge), and is called in full uisge-beatha (in Scotland) or uisce beatha (Ireland), meaning "Water of Life". It is related to the Latin aqua vitae, also meaning "water of life". It is always Scotch whisky (plural: whiskies), and Irish whiskey (whiskeys).
Some scholars believe distilled spirits were first produced between the 8th century AD and 9th century AD in the Middle East with the art of distillation being brought to Ireland and Britain by Christian monks.
Whisky or whisky-like products are produced in most grain-growing areas. They differ in base product, alcoholic content, and quality.
Malts and Grains are combined in various ways
Whiskies do not mature in the bottle, only in the cask, so the "age" of a whisky is the time between distillation and bottling. This reflects how much the cask has interacted with the whisky, changing its chemical makeup and taste. Whiskies which have been in bottle for many years may have a rarity value, but are not "older" and will not necessarily be "better" than a more recently made whisky matured in wood for a similar time. Most whiskies are sold at or near an alcoholic strength of 40% abv.
Scotch whiskies are generally distilled twice, though some are distilled a third time. International laws require anything bearing the label "Scotch" to be distilled in Scotland and matured for a minimum of three years and one day in oak casks, among other, more specific criteria. If Scotch whisky is from more than one cask, and if it includes an age statement on the bottle, it must reflect the age of the youngest whisky in the blend. Many cask-strength single malts omit the age as they use younger elements in minute amounts for flavouring and mellowing. The basic types of Scotch are Malt and Grain, which are combined to create blends. While the market is dominated by blends, the most highly prized of Scotch whiskies are the single malts. Scotch whiskies are divided into five main regions: Highland, Lowland, Islay, Speyside and Campbeltown.
Most Irish whiskeys are distilled three times, although there are exceptions. Though traditionally distilled using the pot still method, in modern times a column still is used to produce the grain whiskey used in blends. By law, Irish whiskey must be produced in Ireland and aged in wooden casks for a period of not less than three years, although in practice it is usually three or four times that period. Unpeated malt is almost always used, the main exception being Connemara Peated Malt whiskey.
There are several types of whiskey common to Ireland: Single Malt, Single Grain, Blended Whiskey and uniquely to Ireland, pure pot still whiskey. The designation "pure pot still" as used in Ireland generally refers to whiskey made of 100% barley, mixed malted and unmalted, and distilled in a pot still made of copper. The "green" unmalted barley gives the traditional pure pot still whiskey a spicy, uniquely Irish quality. Like single malt, pure pot still is sold as such or blended with grain whiskey. Usually no real distinction is made between whether a blended whiskey was made from single malt or pure pot still.
However, in recent years, a number of blind tastings have been organized by Whisky Magazine, which have included Japanese single malts in the lineup, along with malts from distilleries considered to be among the best in Scotland. On more than one occasion, the results have had Japanese single malts (particularly those of Yoichi and Yamazaki) scoring higher than their Scotch counterparts.
The "named types" of American whiskey must be distilled to not more than 80 percent alcohol by volume. "Named types" must then be aged in charred new oak containers, excepting corn whiskey. Corn whiskey does not have to be aged but, if it is aged, it must be in new un-charred oak barrels or used barrels. The aging for corn whiskey usually is brief, e.g. six months.
If the aging for a "named type" reaches 2 years or beyond, the whiskey is then additionally designated "straight" e.g. "straight rye whiskey". "Straight whiskey" (without naming a grain) is a whiskey which has been aged in charred new oak containers for 2 years or more and distilled at not more than 80 percent alcohol by volume but is derived from less than 51% of any one grain.
American blended whiskeys combine straight whiskey with un-aged whiskey, grain neutral spirits, flavorings and colorings.
Important in the marketplace is Tennessee whiskey, of which Jack Daniel's is the leading example. During distillation, it is identical to bourbon in almost every important respect. The most recognizable difference is that Tennessee whiskey is filtered through sugar maple charcoal, giving it a unique flavor and aroma. The Government of the United States of America officially recognized Tennessee whiskey as a separate style in 1941.
Recently at least two distilleries in the traditionally brandy-producing Caucasus region announced their plans to enter the Russian domestic market with whiskies. The Stavropol-based Praskoveysky distillery bases its product on Irish technology, while in Kizlyar, Dagestan's "Russian Whisky" announced a Scotch-inspired drink in single malt, blended and wheat varieties.
At one time, all whisky was spelled without the extra 'e', as "whisky". In around 1870, the reputation of Scottish whisky was very poor as Scottish distilleries flooded the market with cheaper spirits produced using the Coffey still. The Irish and American distilleries adopted the spelling "whiskey", with the extra "e", to distinguish their higher quality product. Today, the spelling whisky (plural whiskies) is generally used for whiskies distilled in Scotland, Wales, Canada, and Japan, while whiskey is used for the spirits distilled in Ireland and America. Even though a 1968 directive of the Bureau of Alcohol, Tobacco and Firearms specifies "whisky" as the official U.S. spelling, it allows labeling as "whiskey" in deference to tradition and most U.S. producers still use the historical spelling. Exceptions such as Early Times, Maker's Mark, and George Dickel are usually indicative of a Scottish heritage.
In the late Victorian era, Irish whiskey was the world's whisk(e)y of choice. Of the Irish whiskeys, Dublin whiskeys were regarded as the grands crus of whiskeys. In order to differentiate Dublin whiskey from other whiskies, the Dublin distilleries adopted the spelling "whiskey". The other Irish distilleries eventually followed suit. The last Irish "whisky" was Paddy, which adopted the "e" in 1966.
"Scotch" is the common term for "Scotch whisky".
In many Latin-American countries, "whiskey" (wee-skee) is used as a photographer's cue to smile, supplanting English "cheese".
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 than vodkas, but significantly less than rums or brandies.
Commercially charred oaks are rich in phenolic compounds. One study discriminated 40 different phenolic compounds. The coumarin scopoletin is present in whisky, with the highest level reported in Bourbon whiskey.