How Whisky is Made
How Scotch Whiskey is Made
Scotch is a distilled alcoholic beverage made at whiskey distilleries exclusively in Scotland. The earliest record of Scotch whiskey making is at Lindores Abbey in the Kingdom of Fife in 1494. Today, there are over 100 distilleries working in Scotland.
Water, grain and yeast are used to create a weak beer which is then distilled in iconic copper stills. The resulting clear spirit is then filled into oak casks where the spirit is left to mature into Scotch. It is this interaction between spirit and oak over many years that gives Scotch it's unique color, flavor and aroma.
Stage #1 Malting
The malting process starts by soaking dry barley in cold water in order to revive them; this is traditionally carried out in a big water tank called a steep located at the end of the barley loft.
The moist barely is then encouraged to germinate. The grain is spread across a floor and turned frequently until the roots and shoots appear. The enzymes released within the barley during germination assist with the breakdown of cell walls and modification of stored starches to form soluble sugars.
The malted barley is transferred to a heating device to end germination. Traditionally it was transferred to the malt kiln where it was spread across a perforated floor and germination ended by hot air rising from the kiln’s fire beneath.
The kiln is fuelled with smokeless fuel. However, if peated Scotch is required peat will also be burned. Traditionally the heat and smoke were extracted through a chimney called a Pagoda roof.
Laphroaig, Balvenie, Bowmore (pictured), Highland Park, Kilchoman and Springbank distilleries produce a proportion of their malt using the traditional Scottish methods.
Stage #2 Mashing
The malted barley is ground in a mill into a coarse flour called grist. Grist is mixed with warm water in a large vessel known as a mash tun. The porridge like mixture is stirred to encourage the soluble sugars to dissolve out of the grist and into the warm water. The process is repeated a couple of times, each time with warmer water. This ensures maximum extraction of sugars from the barely.
The hot sugary liquid is called Wort and is drained off, cooled down and collected. Wort often tastes sweet like a green tea. The waste solid known as Draf may be converted to a feed for livestock or bio-fuels.
The traditional cast iron mash tuns, complete with their internal cogged raking system, in Bruichladdich (pictured), Springbank and Edradour distileries are all over one hundred years old.
Stage #3 Fermentation
Wort is transferred to large containers called Wash-backs, where yeast is added and fermentation takes place. The sugars are broken down and alcohols, including ethanol, and carbon dioxide are produced. The resulting liquid which is around 5-7% alcohol by volume is called Wash and is like a weak beer. When fermentation is complete the wash is drained into a large tank.
The number of washbacks varies between Scotch distilleries, from two at Abhainn Dearg in the Isle of Lewis, six at Bowmore (pictured) and two dozen at Glenfiddich.
Stage #4 Distillation
Distillation of the Worts increases the concentration of ethanol. Wort is heated in a copper wash still and when hot enough the alcohols evaporate up the copper lyne arm and condense in a condenser, traditionally a worm tub. As the gases cool they liquidise; this liquid has an alcohol content of around 20% by volume and is called Low Wines. Traditional worm tubs are still in use at a few Highland distilleries including Pulteney and Dalwhinnie.
The Low Wines pass into the spirit still and are distilled again. The first liquid produced or first cut of this second distillation process is called foreshots and is collected and set aside, the middle cut is the liquid with a high ethanol content which will be converted into Scotch, whilst the third cut is the feints and is also set aside. The first and third cut are used in the next run in the copper wash still. The middle cut is called the new make spirit generally with an alcohol content of 60% to 75% ABV.
Second and subsequent distillations enable concentration of ethanol and removal of unwanted alcohols such as methanol. Most Scotch distilleries operate double distillation although a few including Springbank and Auchentoshan practice triple distillation.
Stage #5 Maturation
The new make spirit is diluted slightly with water prior to filling into oak casks which are then rolled into bonded warehouses and left to mature in peace and quiet in Scotland for a minimum of three years. Scotland's temperate climate is rarely extreme which makes the cool often damp weather ideal for the maturation of whiskey often over many decades.
Casks of varying shapes and sizes are used, most commonly ex-sherry butts, port pipes, ex-bourbon barrels and wine casks. These may be stored in traditional dunnage warehouses with damp dirt floors, stone walls and slate roofs or on racks or palates up to a dozen high in modern warehouses.
Many distilleries continue to use dunnage warehouses, for example Bowmore (pictured), Highland Park and Port Ellen.
Stage #5 Bottling
The bung is removed, the cask rolled on its side and the Scotch allowed to disgorge into a tank. The alcohol content may be reduced by the addition of water and bottle is filled by hand or automated equipment into the flask.
Unlike wine, Scotch does not age any further when in the bottle. The contents are normally retained by a cork stopper. Abhainn Dearg, Bruichladdich and Springbank bottle their whisky at the distillery and use local water.
It's not just Scotch distillers that bottle their own whiskey. Independent bottling companies buy casks and bottle these whiskies under their own labels. This means there is an even greater variety to select from. Lookout for Gordon & MacPhail, Douglas Laing & Co and Berry Bros & Rudd whiskies along with our very own TheWhiskyBarrel.com bottlings!