Single malt Scotch whisky has been made for centuries.
‘It’s a tradition refined over the years by generations of skilled craftsmen so that every ‘dram’ is a small glass of history in its own right.’ Although Scotch is considered an extremely complex and varied drink, it is created using only three simple ingredients, malted barley, yeast and water.
The history, rarity and uniqueness of single malt Scotch whisky, means that human powered malting and the process for creating an inimitable single malt, always remains as true to its past as possible.
How Whisky Is Made
First the barley is malted. It is immersed or steeped in water, and then using wheelbarrows and malt shovels, it is spread out on a malting floor roughly eight inches to one foot deep. To avoid overheating, the barley is continually turned by the ‘maltman’ during this process.
Once the barley roots form the germ, the sugar from the malt is used up and the germination process is stopped. The malt is then ready for drying and heating.
The Malt is spread onto a perforated drying floor above the kiln and is heated to 70°C. The exhaust air is sucked up through the malt removing the humidity, and is released through the traditional ‘pagoda’ shaped chimneys initiated by Charles Doig.
The eventual smokiness of taste is dependent on the how long the malt is dried for. Further distinct individual ‘peaty’ smokiness is created when peat is added to the kiln fire.
The malt is then ground in a ‘malt mill’ and mixed with hot water in a ‘mash tub’ - the sugar, which will later be turned into alcohol, is released with the addition of hot water and driven to the bottom of the tub. This sugary non-alcoholic liquid is commonly known as ‘wart’. The process of adding water is repeated a further two times. The ‘wart’ is only removed the first two times and is the foundation of malt whisky.
The precious liquid is then transferred to a wooden or stainless-steel tank called a ‘washback’ and yeast is added, the fermentation process begins. For the next two days the sugar gradually turns to alcohol. The process is stopped at this point with the alcohol strength generally around 5 -15% ABV.
Scottish ‘Pot’ stills are almost exclusively used in single malt distillation, whilst the ‘Coffey’ still is used for grain whiskies. Scotch whisky is generally, but not always, distilled twice to increase the ABV count of the fermented liquid to above 90% - the maximum ABV allowed for this distilled spirit as laid down by Scottish law is 94.8%. The distillation process not only increases the alcohol content, it also removes detrimental substances like methanol.
The whisky is then placed into a ‘Cask’ to mature. By law, Scotch whisky must mature in oak casks for a minimum period of 3 years. It is during the whisky’s maturation that it takes on the aromas and flavours of the cask.
Two types of oak are used in the maturation process, American white oak and European oak. The flavour and colour of the whisky are predominantly governed by the type of oak used.
The whisky ‘Butt’ cask holds around 500 litres of liquid and is almost always made from European oak originating from Spain, and having formerly contained sherry. As the whisky matures in a ‘Butt’ it will assume a much richer and darker colour. The flavour characteristics will be much fruitier, releasing notes of dark fruit, Christmas cake and spices.
The whisky ‘Barrel’ cask holds around 200 litres of liquid. They are made from American white oak. The whisky in these ‘Barrel’ casks usually has tones of vanilla and coconut with a much lighter more yellow or golden colour.
The ‘Puncheon’ cask also holds 500 litres of liquid, they are mainly made from European oak but can also sometimes be made from American oak.
The fourth type of cask is the ‘Hogshead’. They hold 250 litres of liquid and are almost always made from American oak. The ‘Hogshead’ is created from whisky ‘Barrels’. The general rule of thumb is that four Barrels make three ‘Hogsheads’. At the current time, most of the casks in the system are ‘Hogsheads’.
Older single malt whiskies are kept in the cask to mature for many years with 60 year olds maturing for over two generations.
A Brief History of Scotch Whisky
In an industry that dates back to the 1800’s, single malt whisky has long been part of Scotland’s rich heritage and is its most treasured national asset. However, in the 1940’s to the late 1980’s production of single malt whisky in Scotland all but ceased, with only very limited quantities being produced. The overwhelming majority of single casks were destined for the blended whisky market and it is for this reason that there is such limited supply of aged single cask whisky in the market today.
From a small niche market, a couple of decades ago, demand for single malt whisky has exploded. Demand is still escalating rapidly and supply of the ‘old stuff’ is at an all-time low, this is clearly an opportune time to reap the benefits of this extraordinary success story.
Single malt whisky is the world’s most luxurious spirit and the prestige of drinking and collecting fine single malt has never been as apparent. With the global appreciation for whisky at an all-time high, the message is clear; single malt whisky represents a fascinating and potentially very lucrative prospect for the foreseeable future.
Types of Scotch Whisky
There are five basic categories of Scotch.
- Single malt Scotch whisky means a Scotch whisky produced from only water and malted barley at a single distillery by batch distillation in pot stills.
- Single grain Scotch whisky means a Scotch whisky distilled at a single distillery but, in addition to water and malted barley, may involve whole grains of other malted or unmalted cereals.
- Blended malt Scotch whisky means a blend of two or more single malt Scotch whiskies from different distilleries.
- Blended grain Scotch whisky means a blend of two or more single grain Scotch whiskies from different distilleries.
- Blended Scotch whisky means a blend of one or more single malt Scotch whiskies with one or more single grain Scotch whiskies.
In brief - The Scotch Whisky Regulations 2009 definition of Scotch Whisky
- Produced at a distillery in Scotland from water and malted barley to which only whole grains of other cereals may be added all of which have been:
- processed at that distillery into a mash.
- Fermented at that distillery only by adding yeast.
- Distilled at an alcoholic strength by volume of less than 94.8% ABV
- Wholly matured in an excise warehouse in Scotland in oak casks of a capacity not exceeding 700 litres (154 imp gal) for at least three years.
- Must retain the colour, aroma, and taste of the raw materials used in, and the method of, its production and maturation.
- Containing no added substances, other than water and plain (E150A) caramel colouring.
- Comprising a minimum alcoholic strength by volume of 40% ABV.