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Bruichladdich’s Basic Glossary of Terms as used in this web site

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Aldehydes
Highly reactive, volatile aroma compounds obtained by the oxidation of primary alcohols.
Aldehydes are produced during fermentation and are unpleasantly pungeant but are reduced by 50% during distillation to around 80mg/litre. These compounds can be distilled over and concentrated, mainly in the more volatile, first fraction (heads) of the distillate. The concentration level of these compounds in the distillate can be significant if the still has not been operated properly or their concentration were already high in the starting material. Increases during maturation (oxidation) though the reaction with alcohol during maturation where acetals are formed which soften the pungeant aroma; 20% of aldehydes can become acetals. Acetaldehyde (ethanal – oxidised ethanol) is the predominant aldehyde. Most of the alcohols in whisky can be oxidised to form an aldehyde. For example, ethanol, by far the most abundant alcohol, is oxidised to acetaldehyde. Further oxidation results in an acid (often referred to as a fatty acid). In the case of acetaldehyde, the acid formed is acetic acid. It is the reaction of an acid with an alcohol that yields an ester. Not surprisingly, the most common ester in whisky is the result of the reaction between ethanol and its acid, acetic acid. This yields the ester, ethyl acetate. Rectification reduces the level of aldehydes at distillation. Other aldehydes include aromatic congeners Vanillin, ethanol lignin, Syringaldeyde, coniferaldehyde, sinapaldehyde, and furfural – the ‘malty’ aroma. In the glass these react with air to produce the bouquet. Often these are removed by chill filtration.

Aqua Vitae
The Latin for ‘water of life’, as is the French eau de vie, the Vikings’, acquavit, and the Gaels’ – uisgebeatha, pronounced ‘ooish-ker-vaah’, later being anglicised to ‘whisky’

Blended Whisky
A whisky made from essentially cheaper ‘grain’ whisky with a varying proportion of more flavoursome (and expensive) Malt whisky added often from several distilleries. Each blended whisky has a jealously guarded recipe, such as Bells, Famous Grouse, Haig.

Bog Myrtle

Myrica gale (LINN.) N.O. Myricaceae

Synonyms: Bayberry. English Bog Myrtle. Dutch Myrtle. Herba Myrti Rabanitini. Gale palustris (Chevalier).

The badge of the Campbells. A deciduous, bushy shrub, growing to 4 feet high. The wood and leaves fragrant when bruised. The leaves, not unlike a willow or myrtle, are oblanceolate, tapering entire at the base, toothed and broadest at the apex, the upper side dark glossy green, the underside paler and slightly downy, under which are a few shining glands. The male plant produces flowers in May and June in crowded, stalkless catkins. The fruit catkins about the same size, but thicker, are closely-set, resinous nutlets, the flowers being borne on the bare wood of one year's growth. The sexes are on different plants. The leaves are often dried to perfume linen, etc., their odour being very fragrant, but the taste bitter and astringent. The branches have been used as a substitute for hops in Yorkshire and put into a beer called there 'Gale Beer.' It is extremely good to allay thirst. The catkins, or cones, boiled in water, give a scum beeswax, which is utilized to make candles. The bark is used to tan calfskins; if gathered in autumn, it will dye wool a good yellow colour and is used for this purpose both in Sweden and Wales. The Swedes use it in strong decoction to kill insects, vermin and to cure the itch. The dried berries are put into broth and used as spice. In China, the leaves are infused like tea, and used as a stomachic and cordial.

Bourbon casks
Charred oak barrels used only for the aging of Bourbon in the US - once only. Many are then sold to the Scotch whisky industry and have been in increasing numbers since the end of prohibition in the Sates in 1933. Only the finest quality spirit benefits from maturation in these casks, as they do not heavily influence the maturing whisky as sherry casks can.

Cask
A generic term for an oak container used for maturing whisky, of varying sizes and capacities: Blood Tub = 30 litres Barrels = 190 litres, Hogshead = 250 litres, Butt = 500 litres. The capacities vary from cask to cask and are not exact.

Cask ‘finish’
The current fad of which there is no legal status or control, involves an unnatural process of high pressurisation and heating of whisky to forcibly extract flavours from different types of oak casks, in as short a time frame as possible. We do not agree with this.

Caramel
Added to most whiskies (not here!) to obtain a standardised colour. Also to darken, sweeten the whisky, and in some cases to give the appearance of extra maturity. Often used to imitate sherry cask aged whiskies. Although used in small quantities, un-caramelised whiskies tend to have a cleaner, purer taste.

Cask Strength
Whisky that has been bottled without being diluted – at it’s current strength. Depending on age, this can be any where between 70% when very young and 40% alcohol when around 40 years old.

Chill-Filtering
Chill filtration is an industrial process designed to remove esters in whisky which could form hazes and deposits when stored at low temperature. The principal components responsible for this occurrence are the ethyl esters of lauric, palmitic and palmitoleic acids. These three esters are formed by reacting ethanol with the relevant fatty acid, and are soluble in alcohol, but insoluble in water. This is why we bottle at the higher strength of 46%. Increasing water content in whisky, for example by adding water prior to bottling at a lower % or in the glass, can result in cloudiness as a result of this insolubility. The insolubility of ethyl esters in water tends to increase with molecular chain 1ength. Thus the ethyl esters of acids of shorter chain length (e.g. ethyl acetate, hexanoate, octanoate) do not cause haze problems in whisky. Solubility is also dependent on temperature. When spirits with relatively high concentrations of the highlighted esters are subjected to low or fluctuating temperatures, hazes can appear in the spirit.

Ethyl esters can be reduced by refrigeration followed by filtration known as "chill filtration". Whilst the esters above are minor influences on whisky flavour, chill filtration also removes more flavour critical components, as well as fatty acids that count for the richer ‘mouth feel’ and ‘persistence’ of flavour.

At the North Pole, the whisky remains clear - but long term it would cloud up.

Computers
A mechanical labour-saving device (Ha!). The distilling process in most distilleries are now entirely controlled by them from milling, mashing, to distilling, filling and storing, rendering redundant the human aspect of the art of distilling. But not at Bruichladdich.

Constituents.  Said to contain a poisonous volatile oil and to have properties similar to those of Myrica cerifera. The leaves have been used in France as an emmenagogue and abortifacient.

Customs & Excise
Definitions:

Customs: The term 'Customs' applied to ‘customary payments’ or ‘dues’ of any kind, regal, Episcopal or ecclesiastical until it became restricted to Duties payable to the King upon export or import of certain articles of commerce.

Excise (Duties) from the Middle Dutch excijs, meaning a Duty charged on domestically produced goods. They are inland Duties levied on articles at the time of their manufacture, most notably on alcoholic drinks, but Duties have also been levied on salt, paper and glass.

Diastase
An enzyme that occurs in germinating barley which enables starch present to convert to maltose sugar – which can then be fermented in to alcohol.

Distillation
The process of obtaining higher alcohol levels by separating alcohol from water by means of heat. Alcohol vapours evaporate, when heated, before water. The vapours are then re-condensed. This process occurs twice in two sets of stills: The Wash Still which takes 7% alcohol to 30% alcohol, and the Spirit still which takes 30% alcohol up to 70% alcohol.

Draff
The debris of husks and chaff from the barley left over after the mashing process has finished and all the sugar has been extracted. This is removed from the distillery by local farmers and fed to there cattle. Oddly, local farmers have noted that the draff from Bruichladdich is preferred by their cattle over that of other distilleries. This might be something to do with the gentler mashing process with our ancient equipment? Who knows?


Esters
Esters are the largest group of aroma compounds (36) giving pleasant, very intense aromas. Esters of fatty acids are first formed by enzyme reaction of yeast during fermentation and then the reaction between fatty acids and alcohol. Lightest aroma fraction: Fruit esters, Middle aroma fraction fortifies the lighter, High boiling fraction – the smallest part and heaviest.

The most common, though not he most aromatic ester is Athyl Acetate:

Ethanol (an alcohol) oxidises to acetaldehyde (an aldehyde) oxidises to acetic acid (a fatty Acid) reacts with alcohol to become ethyl acetate (an ester). Ethyl Acetate is present at 420 PPM. Maturation can increase the ester levels by 50% This is commonly removed by chill filtration to prevent haze developing in cold temperatures or on the addition of water.

Ethyl Alcohol
Molecular C2H5OH Synonyms: ethanol, alcohol, absolute alcohol, spirit.

Excise
Excise duties are inland duties levied on articles at the time of their manufacture, most notably on alcoholic drinks, but duties have also been levied on salt, paper and glass. In 1823 an act of Parliament replaced the separate boards of excise for England and Wales, Scotland and Ireland with a single Board of Excise covering the entire United Kingdom As well as being responsible for collecting and administering Customs and Excise duties and Value Added Tax, HM Customs and Excise is also responsible for preventing the evasion of revenue laws, and for enforcing a range of prohibitions and restrictions on the importation of certain classes of goods. See Customs
 

Fatty Acids

22 volatile acids present in whisky that account for various aromas in whisky. Acetic acid  accounts for up to 95%, the  remaining 21 being very pungent  - Capric acid second largest compound, followed by Caprylic acid, Palmitoleic acid (higher if yeast present at distillation) and Butyric acid the most dominant  aromatic. The level of fatty acids increases on maturing at least three fold to 0.32g/litre alc.  These give the ‘persistence’ of bouquet  and viscous, richer  mouth feel of  natural whisky. These are often removed by chill filtration when tying to remove ethyl acetate that can cause haze to develop in cold temperatures or the addition of water. Ethanol (alcohol) oxidises to acetaldehyde (aldehyde)  oxidises to acetic acid (fatty Acid)  reacts with alcohol to become ethyl acetate (ester)

Feints
The weaker strength impure spirit which occurs at the end of the distillation process – after the desirable Middle Cut. Also called ‘Tails’. These can be lethal if consumed and provide the origin of ‘Blind Drunk’.

Fermentation
Where ‘wort’ becomes ‘wash’. The process where yeast eat sugar molecules creating alcohol, and carbon dioxide and heat as by-products. After three days, an alcohol level, of around 7% is achieved, called wash..

Foreshots
The weaker strength impure spirit which occurs at the beginning of the distillation process – before the Middle cut is obtained. Also called ‘Heads’. Also can be fatal.

Fresh Sherry
A first fill cask. Having been emptied of it’s sherry the cask was immediately filled with whisky, which thus obtained the maximum effect of the previous contents. Over many years this influence can dominate the whisky.

Fusel Alcohols

One of the four aroma compositions of whisky , the others being esters, aldehydes and fatty acids. Higher aliphatic alcohols than Ethanol producing aroma. They are produced through the metabolisation of nitrogenous compounds by yeasts. Fusel Oil predominantly consists of higher alcohols - a mixture of amyl alcohols, propanol and butanol, esters, fatty acids and some specific aldehydes formed from distillation. The term fusel oil comes from an old German word "fuseln", which means "to bungle" and was applied to bad spirit. However, many off these compounds are collected as part of the distillate, imparting their own unique flavour complexity, but can be quite obnoxious if in excess. Their harsh attributes require extended maturation time to integrate and mellow., especially amyl alcohol. While not strictly oils have an oily consistency. The non-volatility and oily nature of higher alcohols lies in their high molecular weight and structure. 4 main fusel alcohols, most pleasant is phenylethyl alcohol. Propanol, isobutanol, isoamyl & Pentanol are the major contributors. The total content of fusil alchohol, rather than the individual quantities, determines the strength of the aroma, usually about 1g/litre in whisky. – 100% more in Bourbon, 50% less in Irish.

Grain Whisky
A more efficiently, and thus cheaply, produced whisky made from cheaper grain crops such as maize, and sometimes wheat or barley – distilled in a Continuous (Coffey) still – a form of fractional distillation as used in the oil industry. Grain whiskies tend to be lighter, providing a base upon which to add specific flavours from the more weighty, flavoursome, and expensive single malts producing a Blended Whisky.

Grist
A mix of mainly flour and chaff obtained from passing malted barley through a mill. Hence the phrase: ‘It’s all grist that comes to my mill’ = it is to my advantage. The proportion of flour to chaff is important in determining the release of sugars in the mashing process.

Hogshead
See casks

Islay Water
Bruichladdich is bottled at 46% with water from our own Islay spring. The only whisky in the world to be thus bottled.

Kiln
Where malted barley is slowly dried by hot air derived from fires - coal, oil, peat fuelled or a mixture of two. The amount of peat used in the kilning process will determine the ‘peatiness’ of flavour – the phenolic content – of the whisky.

Low Wines
The result of the first distillation from the Wash Still, at a strength of about 30% alcohol. This is collected in to the low Wines receiver and is then re-distilled a second time in the Spirit Still.

Malt
The abbreviated term refers to malted barley, or the whisky ultimately obtained from the malting process, which occurs in a Maltings building. Here barley is encouraged to begin germinating, after steeping in warm water, causing starch present in the grain to change into sugar by the process of various enzymes. Before the growing seedling can use up this sugar, the germinating process is halted by ‘kilning’ or drying.

Mash
Mash is the mixture of Grist (malted barley flour & chaff) and very hot water that resembles a porridge-like solution in the Mash Tun - a large cast iron vat. The mashing process, where hot water slowly percolates through the Grist taking the now dissolved sugar with it, occurs in the Mash House, and is carried out by a mash man. The resultant sweet, sugary water is called Wort.

Middle Cut
This is the holy Grail. The best part of the distillation, and the highest strength obtained after the weaker impure foreshots have passed and before the weaker impure Feints arrive. The art of selecting when to ‘Cut’ is made by the Stillman. Commercial pressures often dictate to a lesser or greater degree, that the Middle Cut is extended at either end of the ‘run’ in to the foreshots and feints. The purest spirit is obtained by having a shorter Middle Cut (or heart) – and is often the highest strength of alcohol.

Natural Whisky
Non Chill-filtered and Non caramelised whisky; a case of two negatives making a positive?

Peat
The decayed vegetation of bog land anaerobically decomposed over thousands of years and partially carbonised by chemical changes to a sort of precursor to coal.

The vegetation includes mosses, bog myrtle, bog cotton, heather, sedges and grasses. For it to develop, the climate must be cold and wet, the drainage must be poor and the ground poorly aerated. The result is an acidic bog. There are environmental concerns about destroying peat bogs. The whisky industry however uses a small amount and it is therefore not so environmentally damaging. Some peat bogs are 10,000 years old, the layer of peat being as deep as nine metres, sitting like a sponge on top of the bedrock.

In the traditional hand cutting method, the growing sward is removed, and replaced where the previously dug peats have been taken, ensuring that the sward continues to grow – albeit a metre lower down than before. The peats from under the surface (the ‘top’) are crumbly, rooty and oily, which is what the maltsters want for kilning. The deeper peats, the ‘second’, are darker and burn hotter, and the deepest of all (the ‘third’ ) about four to five feet below the surface, dry hard and black, almost like coal. These are the best domestic peats.

The peat is then sliced with a cow-horn topped peat spade, a fal in Gaelic, making an evocative ripping, tearing sound, as the roots are cut. A wet, slippery, spongy black rectangle is removed (a one foot peat represents about 3 thousand years of time) and is placed on the sward. The individual peats are then spread out to dry, where they shrink by two thirds in size as they dry over the summer months.

Mechanical cutting is now more efficient, with a plough-like device towed behind a tractor.

The smoke produced by peat is highly aromatic and oily, and if malt is dried over it, these aromas – called ‘phenols’ by chemists – stick to the grains (coal smoke does not) and ultimately flavours the whisky made from them.

Phenolic Content
Expressed in parts per million, this is an indicator of the level of ‘peatiness’ of a whisky. Zero is non existent – 60 is very high.

Pot Ale
The sludgy liquid that is left at the bottom of the still after the feints have been distilled off. For over a hundred and twenty years this innocuous liquid was sent out to sea by pipeline. Now it is tankered to Caol Ila Distillery, where a new under ground pipeline takes the pot ale out in to the middle of the fast flowing Sound of Islay for dispersal.

Reflux
The process of refining a spirit by repeated distillation. Very tall necked stills (such as Bruichladdich) cause this to happen, for as vapours rise in the tall necks of the stills, they are cooled and re-condense, only to fall back down in to the body of the still, before being re-vaporised. This process is continually occurring before the vapours finally make it into the condensing column. They are thus extremely refined, producing a lighter, elegant and sophisticated spirit.

Run
The flow of raw spirit which comes from distillation

Sherry Wood
A cask, often a 500 litre ‘butt’ that was used to ship sherry from Spain to the UK, and for maturation there of. The different types of sherry contained with in the butt (Fino, Amontillado, Oloroso etc.) having penetrated the wood over time, is leached out by maturing whisky over several years, influencing the flavours and colour of the maturing spirit. Sherry now only bottled in Spain, so the number of butts in the UK has dramatically fallen over the last decade.

Single Malt
A whisky that is produced only from 100% malted barley, at one single distillery.

Spirit Safe
The copper and glass apparatus containing a set of hydrometers, taps and two bowls through which the spirit runs. One safe is allocated to both of the two sets of stills. Here the spirit can be tested for strength in order to determine the precise middle cut. Once selected, the taps are turned to redirect the middle cut in to a spirit receiver or vat.

Stillman
The man responsible for operating the actual still, ensuring the correct regulation of the heat and thus the pace of the distillation, to achieve the optimum quality of spirit. This is an extremely skilful job, with no two distillations ever being exactly the same. See Computers.

Tun Room
A room full of tuns or vats called Washbacks.  Origin of Tun is Celtic, meaning a wine skin container.

Uisgebeatha
See Aqua Vitae

Underback
The tank that receives the ‘worte from the mash tun

Vatted malt
A blend of several different single malts.

Wash
A kind of 7% beer obtained after the ‘wort’ has been fermented. The ‘wash’ is distilled to concentrate the alcohol from 7% to 70%.

Washback
These are huge Larchwood fermentation vessels where the ‘wort,’ having been through a heat exchanger to cool it down, is introduced – along with yeast – for the 3 day fermentation to occur, to create ‘wash’ - or a 7% sort of beer to be distilled.

Wort
A sugar-rich water obtained after the mashing process – where the sugars are leached from the grist (malted barley flour) by hot water.