Whisky Terms and Jargon

ABV

The abbreviation for Alcohol By Volume – the term used to indicate the alcohol content in spirits.

Angel’s share

This is the name for the alcohol that evaporates from a cask while the whisky matures in a warehouse. In Scotland and Ireland, this is about 2% of the contents of each cask per year, although this percentage is higher in other countries with warmer climates.

Blended whisky

A whisky made by mixing different single malt whiskies and grain whiskies to create the desired flavor and characteristics. These whiskies can come from different distilleries and vary in age.

Campbeltown

The once-thriving Scottish whisky-producing region that now only houses a few distilleries. It is located on a peninsula called the Campbeltown peninsula on the west coast of Scotland.

Cask strength

The strength of whisky as it comes directly from the cask. It is not further diluted before bottling, and the strength can vary from 40% to 65% ABV, depending on age. Typically, younger whiskies will have a higher ABV.

Cask

The wooden barrel used to mature the whisky. These are traditionally made from oak. The most commonly used types of oak are American, European, or Japanese.

Charring

The process of burning the inside of a cask. This blackens the inside of the cask and accelerates the release of natural compounds in the wood once the cask is filled with spirit. The degree of charring can be controlled to manage the amount of flavor compounds that transfer from the wood to the whisky during aging.

Chill filtration

The process of removing natural substances that cloud whisky when it is cold or diluted with water before bottling. The whisky is cooled, the natural substances solidify, and are then removed by passing the liquid through a series of metal filters.

Column still

A large industrial distillation apparatus that allows for continuous, mechanized distillation. Column stills are mainly used in the production of grain whisky and are modern and cost-effective. They may also be referred to as a Coffey still, continuous still, or patent still.

Condensation

The process by which alcohol vapors change back into liquid spirit using cooling equipment that is part of the distillation apparatus.

Cooper

A highly skilled person who makes the barrels for aging whisky by perfectly locking the staves of wood together to create a watertight container. This craft is called coopering and takes place in a building known as a cooperage.

Distillation

The process of converting the mildly alcoholic wash into a strongly alcoholic spirit. The wash is heated in a still, and the alcohol vapors evaporate and rise up the neck of the still and travel along the lyne arm, where they are condensed back into liquid.

Draff

The residual grain left over from the mashing process. It consists of barley husks and other parts of the grain, which are then collected, dried, and compressed into pellets for sale as animal feed.

Dram

The traditional Scottish term for a glass of whisky.

Drum malting

This modern method is used to produce malted barley in most maltings. The barley is placed in a large drum and soaked with water. It is then regularly turned for several days until it begins to germinate and becomes “malt.”

Fermentation

The process of converting sugar into alcohol. In whisky production, a sugary liquid called wort is placed in a container called a washback, and yeast is added. This starts fermentation, and after a few days, all the sugar is converted into alcohol and is referred to as “wash.” The liquid has an alcohol strength of between 5-8% ABV.

Floor malting

A traditional method of producing malted barley that is now only used in very few distilleries. The barley is soaked in water and then laid out on a wooden floor for about a week until germination begins. This is highly labor-intensive as the barley must be regularly turned by hand to ensure even germination.

Grist

Malted barley that has been ground into a powder so that it can be added to water to become mash, allowing the natural sugars to dissolve.

Highlands

The Scottish whisky-producing region that covers the large geographical area just north of Glasgow and Edinburgh to the far northern coast. This region includes the subregion Speyside, which is roughly located between the cities of Inverness and Aberdeen.

Islands

The Scottish whisky region that includes all whisky produced on an island. Most of these islands are located off the west coast of Scotland, plus the Orkney Islands to the north of the far northern coast. Most are known for their smoky flavor, as peat was traditionally the only fuel used.

Islay

The most famous of the Scottish islands for whisky production. Islay whiskies are known for their smoky qualities, and the island is home to eight distilleries – more than any other island.

Kiln

The large space where malted barley is heated to stop the germination process and remove moisture so that the barley is ready for grinding. Traditionally, these were heated with peat, but nowadays, most are fired with coal or oil. A number of distilleries on the island still use peat to impart their traditional smoky flavor characteristics.

Lowlands

The Scottish whisky-producing region that encompasses the Central Belt between the major cities of Glasgow and Edinburgh and all areas south of that. Once a traditional powerhouse region, now only a few distilleries remain.

Lyne arm

The part of a still where the spirit vapors are transported to be condensed back into liquid spirit. This arm is usually horizontal or close to horizontal, although some distilleries have deviating shapes or steeper angles for the arm, allowing some liquid spirit to flow back into the still to be distilled again.

Malt

Barley grains that have undergone the malting process (see Malting below).

Malting

The process in which starch in barley is converted into sugar, which in turn can be converted into alcohol during fermentation. Malting is achieved by soaking the barley grains in warm water and then allowing them to germinate, which transforms the starch present into natural sugars. This occurs in a drum or on a malting floor. The malted barley is then dried and ground, resulting in a substance called grist.

Mash tun

A large tank or vessel made of cast iron, stainless steel, or wood, where the mashing takes place. The mash tun is filled with a mixture of grist and warm water, and the soluble sugars in the grist dissolve to form a sugary solution. This solution is then directed through the perforated bottom of the mash tun to go to the washback tank for fermentation.

Mashing

The process of adding grist to warm water and dissolving the natural sugars to create a sugary solution. This takes place in a large tank called a mash tun. The solution is then referred to as wort and is directed to a washback tank to facilitate fermentation. Any grain husks and other residue are referred to as draff and are collected, dried, and turned into animal feed.

Master blender

The person who works for a company or distillery and scientifically selects and blends whiskies of different ages or origins to create the desired final flavor profile of the whisky.

Maturation

The time required for whisky to acquire the optimal amount of character from the wooden cask in which it is stored. Over time, the whisky extracts natural oils and compounds from the wood, and the cask also draws in air from the environment, as wood is a porous material.

Milling

The process of grinding dried malted barley grains into grist.

Neck

The section of a still between the pot at the bottom and the lyne arm at the top. The width and height of the neck regulate the amount and type of alcohol vapors that may rise to the top to be condensed back into liquid spirit.

Pagoda

The pyramid-shaped roof that provides ventilation from the kiln where the malted barley is dried. Designed by architect Charles Doig, who drew inspiration from designs used for centuries in Japanese architecture.

Peat

A layer of earth that lies beneath the surface layer and consists of grasses, plants, tree roots, and mosses compressed over thousands of years. It is a very dense substance that, when dried, is used as fuel. Peat burns at a very constant, high temperature with dense, sour blue smoke. In the whisky industry, peat is used to dry malted barley, infusing the dense smoke into the grains and carrying the flavor throughout the whisky production process.

Pot still

A style of still most commonly used in the production of single malt whisky. They are made of copper due to its excellent conductive properties and consist of the pot at the base (where the alcoholic wash is heated), the neck (where the alcohol vapors rise), and the lyne arm/condenser (where the vapors begin to revert to liquid form).

PPM

The abbreviation for Parts Per Million – the scientific measurement to indicate the amount of phenols in a whisky, which has been absorbed from burning peat.

Purifier

A device connected to the lyne arm that condenses heavier alcohol vapors that are not useful in the whisky production process. It redirects the liquids back to the base, where they undergo further distillation.

Quaich

A traditional Scottish whisky drinking cup consisting of a bowl with a short vertical handle on either side. They are associated with friendship and ancient Celtic stories say that if you share a drink from a quaich with someone, you will be friends for life.

Reflux

The name given to the re-condensation of alcohol that then flows back into the still for re-distillation. The amount of reflux is determined by the shape and size of the still and the angle at which the lyne arm is set.

Saladin box

An old method for malting barley, named after inventor Charles Saladin. The box is a large automated trough with a perforated floor through which air is blown. The germination process of the barley is controlled in the Saladin box by regulating airflow and temperature between the grains.

Shell and tube condenser

A copper tube that surrounds the lyne arm of a still. Cold water is passed through the tube, cooling the alcohol vapors and condensing them back into liquid spirit. It is the most common type of condenser used in distilleries today.

Single malt

Whisky that consists entirely of 100% malted barley and comes from only one single distillery location. They generally contain whiskies of somewhat different ages from various casks within the distillery’s warehouse. These are then blended in a larger container to achieve the desired consistent flavor profile. The age stated on the bottle is the youngest age of any of the whiskies included.

Speyside

The largest Scottish whisky-producing region in terms of the number of distilleries. Approximately 40 of the more than 90 Scottish distilleries are active in this area. The area stretches roughly between the cities of Inverness and Aberdeen and is named after the famous Spey River that flows through it.

Spirit safe

A copper frame with glass walls that is attached to the spirit still. It is used to analyze the spirit as it exits the still. By law, the operator may not make contact with the spirit, and therefore, the spirit safe is locked with a customs and excise officer holding the key.

Spirit still

The second and usually smaller of the two stills. The “low wines” from the wash still are re-distilled in the spirit still – this raises the alcohol content to between 64-69% ABV and purifies the alcohol of undesirable impurities. Only the middle part of this distillation is collected for aging. This portion is referred to as the cut.

Vatted malt

A whisky that consists of two or more single malts that are blended together. Unlike blended whisky, vatted malts contain no grain whisky and consist only of single malts. These can come from the same or different distilleries and may vary in age.

Warehouse

The area where whisky is stored during its maturation. There are two main types. The first is the dunnage or traditional warehouse with earthen floors and stone walls where casks are stacked no more than three high. The other is the racked warehouse, a modern facility with temperature and humidity control where casks can be stacked up to 12 high.

Wash still

Typically, stills operate in pairs, and the wash still is the first and usually the largest of the two. The fermented wash is heated, and the alcohol vapors evaporate and are then cooled and transformed back into liquid by a condenser. The resulting liquid has an alcohol content of 20-22% ABV and is referred to as the low wines. These are then sent to the spirit still.

Washback

A large deep tub or vat in which the fermentation process takes place in a distillery. Traditionally made of wood, nowadays they are usually made of stainless steel.

Worm tub

An older type of device used to cool alcohol vapors back into liquid spirit. The worm tub is connected to the lyne arm of a still and consists of a long coiled copper pipe that is submerged in a wooden vat filled with cold water. The vat is usually located outside and was traditionally filled with rainwater. Fewer than 10 distilleries in Scotland still have this system in operation. Most others use shell and tube condensers.

Wort

A warm, sugary solution that contains the soluble sugars from the malted barley, dissolved in warm water. Wort is the liquid used for the fermentation process, where sugars are converted into alcohol.