An acronym for “Alcohol By Volume.” The alcoholic strength measured as the percentage of alcohol present in the spirit. It is raised during the process of distillation. ABV of whiskey can change as it ages in a cask and is also impacted by humidity and other factors.


An acronym for “Additional Cask Enhancement,” coined by Bruichladdich, referring to the fact that a particular whisky has been taken out of it’s initial ageing barrel, and placed in a different/finishing barrel, until it is ready to be bottled. This finishing barrel can “enhance” the whisky by adding such things as color, aromas, flavors, etc. (See Cask Finish).

Aftershots (a.k.a. Feints or Tails)

The unusable end of a distillation run, after the hearts have been captured.


The age of a whiskey refers to the length of time the youngest spirit in the blend has spent in oak casks. Whiskey stops ageing once it is taken out of the cask.


(see Maturation)


A colorless volatile liquid that is the result of natural fermentation of sugars and is further concentrated through the process of distillation.

American Oak

Also known as White Oak, American Oak is a common wood widely used in whiskey cooperage, a.k.a. – barrel making. American Oak has a high vanillin content. It is also fast growing and possesses a high concentration of lactones. It imparts popular aspects to whiskey that ages in the barrels it goes on to become.

American Single Malt

Currently, the TTB does officially recognize or regulate a category of American Single Malt Whiskey. However, a consortium of American single malt producers are working with the TTB to create an “American single malt” category that more closely mirrors the spirit of the Scottish regulations: 100% malted barley, single distillery, and used as well as new barrels.


An enzyme used in a mash tun to convert the starch into maltose.

Angel’s Share (also called ‘Part des anges’)

As whiskey ages, a small percentage of alcohol evaporates, thus lowering the spirit’s ABV. In Scotland, this accounts for a loss of approximately 2% per year, though the angels’ greed is heightened???(angels share is higher)??? in warmer/drier climates, increasing the rate of evaporation.


An American term for the remaining liquid at the bottom of the stills after distillation. It is used to prevent bacterial contamination by being added to the Washback and Mash Tun between productions.


The composition of a whiskey, in terms of flavors and how well they go together. Balance is usually a positive aspect in a whiskey, and means that the flavors blend well together, with none of them overwhelming the overall mix. Although, through the ageing process balance can also be negatively impacted. Too much time in a barrel may put the whiskey out-of-balance and procure too strong of any particular flavor factor. Too little time in a barrel may not allow the components enough time to meld, and the barrel has not had enough time to draw out negative aspects/impurities in the whiskey.


A cereal grain which is often used in the production of whiskey, and used exclusively in single malt whisky. Various strains of barley are used in whiskey production, all hailing from the grass Hordeum vulgare.


(see yeast) The froth on top of fermenting malt liquor.


A large wooden vessel used to store maturing spirit. In the whiskey world these must be made from Oak (though there are some exceptions for finishing). They are built by coopers and are of varying sizes with the standard size being approximately 40 gallons (180 liters). The larger the barrel, the less wood contact with the spirit. So in theory, a smaller barrel can mature whiskey faster.


(see Blending)


An alcoholic beverage brewed from fermented cereal grains. A liquid can only be distilled if there is alcohol present, thus the production of beer is the first stage in the production of whiskey. This distiller’s beer is called a “Wash” in the whiskey world, and unlike beer, typically does not contain hops.

Beer Still

An American term for a wash still. (See Wash Still)

Blended Malt

A mixing/vatting of malt whiskies from more than one distillery, typically found in Scotch whisky and Japanese whisky. Blended malt used to be known as “vatted malt,” or “pure malt.”


The act of combining one liquid with another. Except for Single Barrel/Single Cask, blending is an important part of whiskey production, where a selection of barrels/casks are blended together bringing various desirable characteristics to the finished product, creating a batch.


An American whiskey distilled from a minimum of 51% corn, distilled to no more than 80% ABV, filled into new charred oak barrels at no more than 62.5% ABV, with a minimum of #3 Char, and aged for a minimum of 2 years. All bourbon is whiskey, but not all whiskey is bourbon. Bourbon must be distilled in the United States, but it may be distilled anywhere within the United States.


The act of mashing cereal grains in hot water and adding yeast to promote fermentation.

Burr Oak

A species of Oak native to North America and some parts of Canada. Also known as Bur Oak, Mossycup Oak and Mossycup White Oak, with the binomen Quercus Macrocarpa. A fast growing Oak often marketed as White Oak, Burr Oak has been used to mature whiskey.


A large cask used for maturing alcoholic beverages (typically sherry), which is made from oak, with a capacity for 105 gallons (477.3 litres) – roughly twice that of a hogshead.


In whiskey terms, the capacity is the amount of pure alcohol (ethyl alcohol in liters) that a distillery can produce in a year.


(see Spirit Caramel)


A wooden barrel in which whiskey is matured and alcohol becomes more concentrated.

Cask Finish

The term refers to the maturation of whiskey, and more specifically, what type of cask the whiskey is last aged in. When a whiskey is transferred from the primary barrel to a secondary barrel for an additional maturation, it is known as a Cask Finish. When a whiskey is cask finished, it sees at least two barrels, those being the primary barrel used for the majority of the ageing, and the second (and possibly third) barrel for the last additional bit of maturation.


A method of filtering whiskey employed to remove residue and a cloudiness which appears when the spirit reaches lower temperatures. Chill-filtration involves chilling the spirit to between -10C to 4°C and then passing it through a very fine filter. At such temperatures the fatty acids, proteins and esters compound as large clumps which are too large to pass through the filter. Practiced particularly to remove solids that modern consumers find unattractive, chill filtering is a controversial method that many believe removes too much flavor and body from whiskies.

Coffey Still

An enhanced version of the continuous still. It was enhanced and then duly patented in 1831 by the Irishman, Aeneas Coffey. (Reword, ensure facts are straight.)

Column Still

(see continuous still)

Commercial Malting

Malting done on an industrial scale. Most commercial malting is done by drum malting, although there are a small number of malting companies and distilleries that carry out the malting process in the traditional manner of floor malting.


Chemical compounds, impurities formed during fermentation. They pass through the entire process and impact the whiskey in its finality. It is said that these proffer the majority of characteristics present in whiskey.

Continuous Still

A distillation device which involves constant distillation and re-heating of an alcoholic liquid. This is an extremely efficient method of distillation and the distillate can be as high as 96% ABV, though the spirit retains less character, thus is not favoured for whiskey production.


A person who makes the oak barrels used for the maturation of spirits and other beverages.


A grain used in whiskey production, particularly favored in America, and in the production of Bourbon, which must be distilled from at least 51% corn. Corn contains high levels of starch and protein, and can offer the highest yield of alcohol. It gives a whiskey a gentle sweetness, spice and an earthen character.


An enzyme present in cereal grains which breaks down cell walls and allows access to starch.


Distillation is the method of separating parts of a liquid based upon their differing boiling points. To produce a spirit, an alcoholic liquid is heated to a point at which the alcohol evaporates, leaving the remaining liquid behind. This gaseous alcohol is then condensed and collected. This is the basis for which all spirit production occurs, the alcohol evaporates at 78.29°C.


Also known as Tails or Aftershots, is the unusable end of a distillation run.


When a plant begins to turn from a seed into a plant. In whiskey production forced germination of grains is practiced in order to turn the starches into sugars.

Hard Water

Water with a very high mineral content that has traveled over soft rock, which imparts ions; impacting the flavor.


Following Mashing, the Mash is moved to a Lauter; a vessel with a sieved bottom.

Malt Barley

Barley that has been gone through a partial germination before being kilned. The malted barley is then ground to a fine flour, or grist.

New Make

Recently distilled spirit that is “fresh off the still.” It is whiskey that has not seen any oak/finishing time.


The variety of wood used as a material for building barrels, as well as a number of other items used during the production of whiskey. Oak is native to the Northern Hemisphere and has about 400 species. It is quite a dense wood with superb strength, but is porous enough to allow for changes to take place within, as the whiskey contained inside changes with time in the oak barrel. It also has a high tannin content along with vanillin, among other flavor compounds.

Racked Warehouse

A warehouse design originating in the 1950s that allows for the stacking of barrels eight high. Because of their size, forklifts and other technologies are employed for ease.

Unpeated Malt

Unpeated Malt: Malted Barley that has been kilned over fires not fuelled by peat, leading to a very little or no phenolic content.


A large pipette used to draw spirit for sampling from a cask.


Fermented Wort similar to beer at about 7 or 8% abv.

Yeast (or Barm)

A micro-organism from the Fungi kingdom. Yeast is  added to the wort to start the fermentation process where it feeds on the sugars and produces carbon dioxide and ethyl alcohol. Different forms of yeast exist imparting different characteristics in all sorts of industry products.