Philip Day provides a buyers guide to Single Malt Scotch Whisky, the purest form of scotch whisky, that has been distilled for centuries in Scotland using traditional techniques. 

A Buyers Guide to Single Malt Scotch Whisky

The purest form of scotch whisky is Single Malt Whisky, that has been distilled for centuries in Scotland using traditional techniques. There are many varieties of Malt Whisky, yet the purist will often avoid blended malts and those at the cheaper end of the market often to be found on supermarket shelves.

In order to introduce the uninitiated to the world of Malt Whisky, all of which possess very different characteristics, it is necessary to look in detail at the different varieties available in the five main Malt Whisky producing regions of Scotland, to identify those brands worthy of investment for a pleasurable drinking experience.

The Scotch Whisky Regulations 2009

While ‘Scotch Whisky’ has a legal definition, terms such as ‘Single Malt’; have traditionally been governed only by industry conventions and general laws relating to trades descriptions. Since 23rd November 2009, under the ‘Scotch Whisky Regulations’, such terms have been defined in law to ensure consumers always receive clear and accurate information about what they are buying.

A Buyers Guide to Single Malt Scotch Whisky

The Scotch Whisky Regulations 2009

‘The Scotch Whisky Regulations 2009 ‘ formally define five categories of Scotch Whisky, namely:

  • Single Malt Scotch Whisky – a Scotch Whisky distilled at a single distillery (i) from water and malted barley without the addition of any other cereals, and (ii) by batch distillation in pot stills. From 23 November 2012, Single Malt Scotch Whisky must be bottled in Scotland.

  • Single Grain Scotch Whisky – a Scotch Whisky distilled at a single distillery (i) from water and malted barley with or without whole grains of other malted or unmalted cereals, and (ii) which does not comply with the definition of Single Malt Scotch Whisky.

  • Blended Scotch Whisky – a blend of one or more Single Malt Scotch Whiskies with one or more Single Grain Scotch Whiskies.

  • Blended Malt Scotch Whisky – a blend of Single Malt Scotch Whiskies, which have been distilled at more than one distillery.

  • Blended Grain Scotch Whisky – a blend of Single Grain Scotch Whiskies, which have been distilled at more than one distillery.

Additional regulation from 22nd November 2011

Additionally, from 22nd November 2011, the relevant category description must appear clearly and prominently on every bottle of Scotch Whisky sold.

Legal protection

Today, the term ‘Scotch Whisky’ is defined in UK law, and also protected at European Union and World Trade Organisation level as a recognised ‘geographical indication’. This legal protection is vitally important. It protects Scotch Whisky from unfair competition and underpins the reputation of Scotch Whisky as being of the highest quality and integrity.

Malt whisky must contain no grain other than malted barley. Grain whisky may contain unmalted barley or other malted or unmalted grains such as wheat and maize (corn).

Whisky was historically produced in pot stills until the development of the continuous still around 1831. In current practice, some finer whiskies are still produced using pot stills, although most whisky production is currently produced by continuous distillation. Under the ‘Scotch Whisky Regulations of 2009’, single malt Scotch whisky must be distilled using pot stills.


A Buyers Guide to Single Malt Scotch Whisky

The main, protected malt whisky producing regions are as follows:

  • Speyside Single Malt Whisky

  • Highland Single Malt Whisky. (Island Single Malt Whisky an unrecognised sub-region that includes all of the whisky producing islands excluding Islay)

  • Lowland Single Malt Whisky

  • Islay Single Malt Whisky

  • Campbeltown Single Malt Whisky

The process of making a good Scotch Malt Whisky

1. Malting

A Buyers Guide to Single Malt Scotch Whisky

Malting Floor at Highland Park Distillery

Malt whisky production starts when the barley is malted—by steeping the barley in water, and then allowing it to get to the point of germination.

Malting releases enzymes that break down the starches in the grain and helps to convert them into sugars.

When the desired state of germination is reached, the malted barley is dried using heated air. Many (but not all) distillers add smoke from a peat-burning fire to allow a smoked, earthy flavour to permeate the spirit.

2. Mashing and fermentation

The dried malted barley (and in the case of grain whisky, other grains) is ground down into a coarse flour called ‘grist’. This is mixed with hot water in a large vessel called a ‘mash tun’. The grist is allowed to steep for a while. This process is normally referred to as ‘mashing’, and the mixture as ‘mash’.

In mashing, enzymes that were developed during the malting process are allowed to convert the barley starch into sugars, producing a sugary liquid known as ‘wort’.

A Buyers Guide to Single Malt Scotch Whisky

The wort is then transferred to another large vessel called a ‘wash back’ where it is cooled down. Yeast is then added, and the wort allowed to ferment. The resulting liquid, now at about 5–7% alcohol by volume (ABV), is separated from solid matter by filtering, and is at this stage a rudimentary form of beer called the ‘wash’.

3. Distillation

Next, a still is used to distil the wash to increase the alcohol content and to remove undesired impurities.

A Buyers Guide to Single Malt Scotch Whisky

There are two types of stills in use for distillation: the ‘pot still’ (for single malts) and the ‘Coffey still’ (for grain whisky). Most Scotch malt whisky distilleries distil their product twice. (Exceptions include: the Auchentoshan Distillery and Springbank’s ‘Hazelburn’ brand, which retain the Lowlands tradition of triple distillation.)

A third method,unique to the Springbank Distillery’s ‘Springbank’ brand, is distilled “two-and-a-half-times”.This is achieved by distilling half the low wine (1st distillation) for a second time, adding the two halves to each other and then distilling the complete volume a second and final time.

For malt whisky the wash is transferred into a ‘wash still’, where the liquid is heated to a boiling point, which is lower than that of water. The alcohol evaporates and travels to the top of the still, through the ‘lyne arm’ and into a condenser—where it is cooled and reverts to liquid.

At this stage, the liquid has an alcohol content of about 20% and is called ‘low wine’.

The low wine is distilled a second time, in a spirit still, where distillation is divided into three ‘cuts’.

The first liquid or cut of the distillation is called ‘foreshots’ or ‘heads’ and is generally quite toxic because of the presence of too many volatile compounds It contains an excess of acids, aldehydes and esters. These are generally saved for further distillation.

The distiller looks for the ‘middle cut’, which is placed in casks for maturation. At this stage it is called ‘new make’. The alcoholic content of this can be anywhere from 60%–75% ABV.

The third cut is called the ‘feints’ and is generally quite weak. These are also saved for further distillation.

Grain whiskies are distilled in a column still, which requires a single distillation to achieve the desired alcohol content. Grain whisky is produced by a continuous fractional distillation process. Unlike the simple distillation based batch process used for malt whisky, it is therefore more efficient to operate and the resulting whisky is less expensive.

The maximum distillation purity prescribed in the ‘Scotch Whisky Regulations 2009’ is 94.8% alcohol by volume (ABV). This allows the spirit to have a rather high level of alcohol purity – approaching that of neutral spirits, contrasting with the maximum of 80% ABV allowed for ‘straight’ American whiskey. High levels of alcohol distillation purity can give the whisky a lighter (but less rich) flavour.

In practice, Scotch single malts are generally not distilled to very high levels of alcohol content, in order that they can retain more of the flavours of the original wash.

4. Dilution prior to ageing

Most newly-made malt whisky, ‘New-make spirit’ is diluted to about 63.5% ABV before it is placed in casks to mature.

5. Maturation

Once distilled, the “new make spirit” is placed into oak casks for the maturation process. Historically, Spanish and Portuguese casks previously used for sherry or port were used (as producing new barrels was (and still is) expensive, and there was a ready market for used sherry butts). Today, most of the casks typically used are imported from northern France, with its ready supply of aged, white oak casks used in the production of red and white wine, in addition to used sherry or bourbon casks.

American whiskey production generates a nearly inexhaustible source of used barrels,as a result of a United States regulation requiring the use of new, freshly charred oak barrels in the maturation of bourbon and many other types of whiskey.

A Buyers Guide to Single Malt Scotch Whisky

The ageing process causes evaporation of the spirit, so each year a whisky matures in the cask results in a loss of volume, as well as a reduction in alcohol. The 1½–2% lost each year is known as the ‘angel’s share’.

Many whiskies along the west coast of Scotland and on the Hebridean Islands are stored in open storehouses on the coast, allowing the salty sea air to pass on its flavour to the spirit.

By law, the distillate must age for at least three years and one day in Scotland to earn the appellation ‘Scotch whisky’, though most single malts are aged to a minimum of eight years of age.

Some believe that older whiskies are inherently better, but others find that the age for optimum flavour development changes drastically from distillery to distillery, or even from cask to cask.

Older whiskies are inherently scarcer, however, so they usually command significantly higher prices.

The colour of the spirit can give a clue to the type of cask used to age the whisky. Sherry casked whisky is usually darker or more amber in colour, while whisky aged in ex-bourbon casks is usually a golden-yellow/honey colour. However, it is worth remembering that the addition of legal “spirit caramel” can sometimes be used to darken an otherwise lightly coloured whisky.

6. Vatting and dilution

The properly aged spirit (Single Malt) may be ‘vatted’, or ‘married’, with other single malts (sometimes of different ages) from the same distillery. The whisky is generally diluted to a bottling strength of between 40% and 46% ABV.

Occasionally, distillers release a ‘Cask Strength’ edition, which is not diluted and usually has an alcohol content of 50–60%ABV.

A Buyers Guide to Single Malt Scotch Whisky

Many distilleries release editions, which are the product of a single cask that has not been vatted with whisky from any other casks.

These bottles usually have a label that details the date the whisky was distilled; the date it was bottled; the number of bottles produced; the number of the particular bottle and the number of the cask from which the bottles were produced.

Additional Information

  • The Scotch Whisky Association has a very informative website, where you can find out more about Whiskies, single malts and their production. Find out more here:


  • Malt Whisky Yearbook 2012, Ronde I, 2011, MagDig Media Limited, Shrewsbury, Shropshire, England, UK.
  • 101 Whiskies to Try Before You Die, Buxton, I, 2010, Hachette Scotland, London, UK

  • The Scotch Whisky Regulations 2009

  • The Scottish Whisky Association

  • Wikipedia

  • Scotch Whisky





  • All other images from Scottish Whisky Association

About the author

Philip Day is an early-retired academic in linguistics who has published many articles.

A North-Midlander (The Potteries) by birth, he currently lives close to the Lancashire Pennines which he regularly explores with his Patterdale terrier, Max.

In particular he has a keen interest in European fine wines and good food and will be contributing further articles in the future for

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