Whisky Made Me Do It: 60 wonderful whisky and bourbon cocktails. Ruby Taylor

Japan, the Ministry of Environment has designated the water sources for Suntory Whisky’s brand as being among the ‘most precious’ in the country. The distilleries in Scotland, Ireland and Canada are no different. The unique pH for each water source brings out certain flavour profiles in each whisky.

      Maturation occurs primarily through oak barrels, but the size of the barrel, whether it is new oak or has been used before, what kind of oak and how long it is used for aging all affect the final flavours of a whisky. Some distillers use more unusual techniques for maturation, from sending their barrels to sea on ships, to playing music to it as it rests, but it’s the magic that happens in the barrel that allows the whisky to mature. Many attempts have been made to speed up the maturation process, including using high pressure, ultrasound or other techniques to fake the effects of barrel aging. None have successfully replicated the correct flavour profile.

      Climate plays a major role in whisky maturation. In hot Kentucky, where new oak barrels are stored in tin-sided ‘rick houses’, the heat creates an angel’s share (evaporation of liquid in the barrel) that can reach 10% in year one as the liquid seeps into the porous wood staves, and can average 4% per year for the remainder of its maturation. In contrast, Scotland, which experiences a much lower average summer temperature, allows distillers to write off 2% per year to the angel’s share. Other factors are affected by the climate; in an environment with warm temperatures and high humidity, more alcohol will evaporate out of the barrel than water, lowering the abv as it matures, while in a lower-humidity environment water evaporates, which raises the abv.

      The kind of still used and how many times a product is distilled affect the final whiskies. There are essentially two types of still:

      The pot still is the older, less-efficient method of distillation. Modern pot stills are steam heated or occasionally heated by fire. The shape of the still is a good indicator of the type of whisky it is producing – a short, round still with a short neck will produce a fatter, more full-flavoured whisky, while a taller, thinner still with a long neck produces a milder, gentler whisky. A pot still works in batches, and one distillation can achieve an abv maximum of 40–80%. Pot-still whiskies are generally distilled twice, and sometimes three times. A mixture called ‘distiller’s beer’ or ‘wash’ is put into the still, which is a cloudy liquid that remains after fermentation. The first distillation yields what are known as low wines, usually around 20% abv. The resulting liquid is then put into a second pot still (or the first still is reused), and second distillation with heads and tails cut (known as feints and fore shots) has to be made to ensure that only the heart of the run is captured. Any liquid left behind in the still (sometimes called pot ale) is discarded or turned into animal feed.

      The column still, also known as the continuous still or Coffey still, consists of two columns that continuously distill the spirit. The first column has the wash pumped in from the top while steam comes up from below. A series of either bubble plate or a packing material inside helps the fractional distillation. The second still, the rectifier, condenses the alcohol vapours into liquid form. A column still is much more efficient, being able to distill to a 96% abv, or as close as can be achieved without the use of chemicals or specialised lab equipment. While this still can be run constantly, and extract a purer base alcohol, it does mean less flavour comes through.

       STYLES OF WHISKY

      As France is to wine, Scotland is to whisky. No true connoisseur can ignore the variety and depth of the whisky produced there. Scotch whisky comes in five different styles but around 90% of all that is produced in Scotland is blended. To be labelled as Scotch whisky, it must be distilled in Scotland from water and malted barley and may include other cereal grains. It can be distilled to no more than 94.8% abv. The whisky must be matured for a minimum of three years in oak casks not larger than 700 litres, then bottled at a minimum alcoholic strength of 40% abv. Scotch whisky allows the addition of caramel colouring for colour correcting.

      This is a good moment for a note on barrels. The majority of casks used for maturation of Scotch whisky (about 97% of Scotch maturing at any time) are ex-bourbon barrels made from American oak (Quercus alba). By American law, bourbon barrels can only be used once, so the majority are broken down and the staves shipped to Scotland. The staves are then rebuilt into barrels, with new ends added, and the staves are re-charred to release more wood sugars. This can be done many times during the useful life of a barrel (30-plus years), but the first time it is used to hold Scotch whisky is referred to as a First Fill Barrel (the most esteemed by whisky enthusiasts). This has the greatest bourbon influence, which depletes as the barrel is reused. Sherry butts represent the majority of the other casks used to mature Scotch whisky and are much larger, at 600 litres. Other barrels are often used to ‘finish’ a whisky for 30–90 days at the end of its maturation, when the whisky is transferred to a new barrel for a short time to pick up some of its characteristics. This will be labelled ‘Rum Cask Finished’ or ‘Gaja Barolo Barrel Finished’.

      Peat is one of the most divisive flavour compounds in Scotch whisky. Many people adore it for the smoke and phenol compounds with which it can imbue malted barley, but some find it an acquired taste. I come down firmly in the ‘adore’ category. So why is peat in whisky? Simply put, peat is an accumulation of decayed vegetation that forms in bogs. In older times, malted barley would have dried on screens set over burning peat, for the smoke to add its distinctive flavour. Peat is also close to the concept of terroir (flavours that reflect the unique environment of each wine), because various areas have different types of peat based on what grew there thousands of years ago.

      BLENDED SCOTCH WHISKY makes up the large majority of Scotch whisky sold worldwide. This style was created when whisky merchants and grocers in the 19th century realised that by mixing single malts, which were rougher and more inconsistent, with relatively new grain whiskies (made from corn or wheat) produced on column stills, they could create a consistent house style that was generally lighter and sweeter, and more marketable to a broader range of consumers. Today, Master Blenders still strive to recreate the same flavour profile of a particular whisky year in and year out. If an age statement is listed on the label of a blended Scotch whisky, it must reflect the age of the youngest whisky in it. The average ratio of grain whisky to single malts runs from 60–85% grain whisky to 15–40% single malts.

      SINGLE MALT SCOTCH WHISKY is the second-largest category of Scotch sold worldwide. A single malt must be made from malted barley and distilled in a pot still, usually twice. It has to be made at a single distillery, where it is blended to create a harmonious whole to reflect that distillery’s style. There are five official regions for single malt whisky in Scotland, although a sixth, the ‘Islands’, is unofficially argued by many whisky enthusiasts:

      The Lowlands – The whiskies produced in the southernmost area of Scotland are gentle and sweet. Some have been affectionately referred to as ‘breakfast whisky’ because of the regional tradition of triple distilling, which results in a lighter style.

      The Highlands – Physically the largest whisky-producing region in Scotland, its size allows for a variety of styles, from peaty and large to light and floral.

      Speyside – This area features the most densely concentrated number of distilleries within its small borders. With production centred on eight locations – Strathisla, Livet, Findhorn, Rothes, Dufftown, Deveron, Lossie and Speyside Central – the whiskies are generally light and fruity with some grassy characteristics, with a greater influence of sherry casks than in other regions.

      Campbelltown – This is the only town to be its own whisky region. At its peak, the area featured 30-plus distilleries, all producing powerful whiskies known for their smoke and salinity balanced by fruit and chocolate notes. Now only three remain.

      Islay (pronounced EYE-luh) – The southernmost island in the Inner Hebrides