An Introduction To Single Malt Whisky
- What Is A Single Malt?
- How Malt Whisky Is Made
- Flavour Variations
- Regional Characteristics
- Enjoying The Whisky
Whisky is the fruit of a northern climate. The term whisky is a derivative of the expression “water of life” known in in Gaelic as “uisge (pronounced ooska) beatha.” Over time uisge has been Anglicised to “whisky.” The first whiskies were produced in the 15th century by monastic orders. The first tax on production, in the mid 17th century, had the effect of stimulating illegal production. This may account for the remote location of many distilleries. In 1823 the Excise Act was introduced to license distilleries. As a result the industry became, if not more expensive, at least more respectable. There are currently somewhere around 90 producing distilleries in Scotland.
Single Malt Whisky is a distilled spirit made entirely from malted barley at a single distillery. The most notable examples of this are made in Scotland and are thus referred to as scotches. But not all scotches are single malts. Vatted Malts or Pure Malts are blends from the malt whisky of several different distilleries. A whisky that is labeled generically “scotch” is blended and contains only 40 to 60% malt whisky with the remainder comprised of whisky made from cheaper unmalted grain. All whisky must be aged for a minimum of 3 years before it can be described as such.
Malt whisky is basically a distilled, un-hopped beer. Barley is malted to convert starch into fermentable sugars. To this end the barley is germinated (traditionally in floor maltings) and then kiln dried over peated fires. In the past, peat was used because of it’s availability, but now it is used primarily to impart flavour to the malt.
The malted barley is ground in a mill and is then referred to as “grist.” The grist is loaded into a vessel called a mash tun and is warmed with water to 64°C. At this temperature the enzymes present in the malt convert the remaining starches into sugar. The solution that is drawn off of the mash tun is referred to as “wort.” The wort is pumped to another vessel called the washback. Yeast is added to the wort to ferment the sugars, producing alcohol.
When the fermentation is complete, what is now called the “wash” is boiled in a series of two, or sometimes three, pot stills. Condensate is taken off of the first still and added to the second. This process concentrates the alcohol as it has a lower boiling point than water and will condense first. The liquid that comes out of the stills has an alcohol content of between 60 and 75% which is blended and diluted to an average strength of 65% before it is put into oak barrels for maturation.
The whisky will have a strength of between 50 an 60% alcohol after the losses that are incurred by evaporation in the barrel during aging. Before bottling the whisky is further diluted to 40 or 43% alcohol.
Water. The water used in most distilleries is soft. It is common wisdom that the best water sources are those that rise from granite over peat. The flavour the source water picks up from its journey is concentrated by the distillation process.
Peat. The amount and character of peat used in the kilning process has a pronounced effect on the flavour of the whisky.
Stills. The shape of the pot still , the angle of the lyne arm that leads to the condensing unit, as well as the degree of heat applied affect the flavours that are captured in the distilled whisky. Taller stills tend to produce lighter whiskies.
Casks. Whisky will usually spend 8 to 15 years in an oak cask. The type of wood used and the micro-climate of the maturation warehouse have a profound influence on the character of the whisky. Most casks are made from American oak, some of which have previously been used for the storage of bourbon. Some distilleries used old sherry casks which impart a sherried flavour to the spirit. The traditional maturation warehouse is damp with earthen floors. The humidity cuts the rate of evaporation in the barrels. In some coastal distilleries the sea air is said to imbue a certain briny character to the whisky.
Lowlands. Whisky from the Lowlands region tend to be lighter, softer, and less peated.
Highlands. The Highlands are where the bulk of single malt whisky is produced. As it encompasses a very large area, the whisky produced in this area is stylistically very broad. Generally Highland whiskies are known for their depth and complexity.
Islay. The most distinctive single malts are produced on this island. These malt whiskies tend to be well peated with a smoky characteristic. Some phenolic, medicinal, or sea overtones are typical.
Enjoying The Whisky
With idiosyncratic character and a lingering finish, Single Malt Whisky is made to be sipped. Although smothering your single malt with ice or soda water is not recommended, don’t be afraid to add a little cool water to the whisky. Drink it at a strength that allows you to appreciate subtleties in the flavour. Spring water is ideal as it has a more neutral flavour than tap water.
Sources: Malt Whisky Companion, Michael Jackson, ISBN 0-07-551056-1; A Little Book of Scotch Whiskies, Derek Cooper, ISBN 0-8118-0253-1.