No-one knows exactly when whisky was first distilled in Scotland, with the first written historical reference to it noted in the Exchequer Rolls in 1494, but it’s believed that the practice dates back much further than that. That record related to distilling being done by monks at Lindores Abbey in Fife, and even after monasteries were dissolved by Henry VIII in the 16th Century illegal whisky production continued to grow over the next few centuries.
By 1824, over 4 million gallons of whisky was being produced in Scotland according to tax records and the 19th Century saw an explosion in new distilleries being opened as production methods became more sophisticated and efficient. Each distillery has its own unique methods and specifications in the creation of what was known as ‘uisge beatha’ (Gaelic for the Latin phrase aqua vitae or ‘water of life’) and was eventually called ‘usky’, and then ‘whisky’.
The two types of scotch whisky are malt whiskies and grain whiskies, with malt whiskies usually divided up by the location in Scotland they are made. Lowland malt whiskies are those produced south of Dundee and Greenock, with Highland malt whiskies coming from north of those areas. There’s also more location-specific malt whiskies where the distinctiveness of the production makes them stand out from those two categories, like those from Speyside, the island of Islay and Campbeltown.
The way these malt whiskies are produced varies greatly as does the finished product, with Islay whiskies usually much heavier than the Lowland whiskies. Grain whiskies generally have much less geographical distinctions and are produced all over Scotland with much the same results. However, whisky may only be described as scotch whisky if it has been distilled and matured in Scotland for at least 3 years, and this is enshrined in laws around the world. This is because there’s so much uniquely Scottish about the way whisky is produced in Scotland, including the type of water and peat used in the process.
One of the main distinctions between different distilleries in Scotland is the source of the water and peat, indeed whether peat is used at all, along with the sizes and shapes of stills and the techniques used, which have been passed down from generation to generation. Even the climate plays its part, especially during the maturation process, where the cool, soft air permeates the casks and helps to mellow the whisky in a way that would be completely different in countries with different climates.
There are around 100 distilleries in Scotland and while every distillery has its own bespoke traditions, there is a generic process that has been used for generations, and here is a run down of the basic distillation principles.
The first step sees the barley steeped in water and allowed to germinate by spreading it out and turning it regularly on malting floors. This helps to prevent the build-up of heat and activates the enzymes that convert the starch to sugar during the next stage. The germination process takes around a week before the malt is taken to dry in the kiln. Some distilleries add peat to the fire to boost the flavour, but it is important that the heat never gets above 70°C.
Once it’s dry, the malt is ground into grist and put into the mash tun with increasingly hot water added in 3 phases. It’s then stirred to turn the starches into sugar and the end result is wort, while the draff (the leftover grains) get turned into food for cows.
Meanwhile, the wort gets cooled until it’s 20°C before yeast is added in washbacks to start the 2-day fermentation phase of the process. This is where the yeast feeds on the sugars to produce alcohol – 6-8% at this stage as well as other compounds that all go together to make that recognizable whisky taste.
Where each distillery differs in its production of whisky is in the shape of the pot still and how that affects the finished product. At this stage of the process the still gets heated to vaporise the alcohol before being condensed back into a liquid in a copper coil or condenser.
The next stage sees it distilled twice, firstly to separate the alcohol from the water, yeast and residue, and this takes place in the wash still. The leftovers are again used for animal feed, while the low wine that is produced moves on to the spirit still to be distilled again before the heart of the run (68% alcohol) is collected in the spirit receiver.
The final stage sees the distillates pass through what’s known as the spirit safe, where the stillman tests to make sure it is of the right quality, though without actually coming into contact with it. After this, the whisky is put into oak casks to begin maturing. Scotch whisky must be matured for a minimum of three years but is generally done for at least 8 years and sometimes much longer. This helps the whisky to become smoother, more full of flavour and the cask also induces that familiar golden colour while each distillery’s unique compounds created during the production will add subtle differences to the finished whisky.
Scotch grain whisky is made in a slightly different way, usually from 10-20% malted barley along with either maize or wheat, which is pre-cooked to release the starch and convert into fermentable sugars. After it has been mashed and fermented in the same way as malt whisky, it is distilled in a Coffey still with two tall columns. These are called the rectifier and the analyser and act like a heat exchanger, where cold wash meets steam before the alcohol is cooled and condensed into Scotch grain spirit. It takes less time to mature than malt whisky because it is lighter. While single malt whiskies are certainly popular, the vast majority of Scottish whiskies drunk all over the world are blended. These can be blended malts, with no grain whiskies but are typically a blend of around 60-80% malt and 20-40% grain and after the blend has been chosen they are left to marry in casks.