Whisky is about so much more than the fluid in your glass; there is a vision, a story, a very particular process that is a blend of science and art. I spent many years enjoying whisky but never truly understood exactly how it was made and why it was so varied. No matter where you are on your whisky journey; if you are just starting out or if you are an experienced drinker, to understand and appreciate the processes used to make whisky and how each stage can influence the flavour, can deepen your experience and ultimately improve your enjoyment of this marvellous malt. Below, is a simplified outline of the main steps of the scotch whisky-making process and the impact each has on the spirit.
Harvest
The most common grain used for whisky and in particular Scotch whisky is barley and although there are over 5,000 strains of barley, only 10 are approved for use in Scotch whisky production.
Malting
For malted Scotch whisky, a malting process is used for controlled germination of the barley, which allows the starch within the grain to be converted into fermentable sugars. Nowadays, this is often done using machines, but was traditionally a manual process using large malting floors, with workers using shovels to continually turn the malt that could lead to a 'Monkey Shoulder.'
Kilning
This uses warm air to halt the germination process, ensuring the starch in the barley is not used up. This is also where you determine whether to have a peated or non-peated malt.
Coke or coal fueled fire does not impart any noticeable flavour on to the malt
A peat fueled fire creates phenols that will attach themselves to the damp malt and result in a peaty malt and ultimately a peated flavour to the spirit. The amount of exposure will determine how many phenols attach to the malt (how peaty the malt is), which is measured in parts per million (PPM).
Milling
Malted barley is ground down to create Grist, which is ready to be used for fermentation.
Mashing - The Grist (ground down Barley) is added to hot water, which dissolves the starches and the enzymes produce simple sugars that can be used by the yeast during fermentation. This sugary liquid is called the Wort.
Fermentation – Yeast is added to the Wort (the sugary liquid made of water and ground barley), which metabolises the sugars to release ethanol (alcohol). This usually takes around 48 hours.
Secondary Fermentation – Many distilleries now ferment for over 90 hours, which creates a much sweeter and fruiter spirit, but this relies on bacteria and wild yeasts that are in the mixture; a process known as secondary fermentation.
Distillation – This is all about copper contact, with many distilleries using copper pot stills to heat the liquid, turn it to a vapour and allow it to condense back to a liquid. The more times it does this and the greater the copper contact, the lighter and more refined the final liquid will be. The opposite produces a heavier, denser and oilier spirit.
The Pot Stills at Penderyn Distillery
The Cut
This is where the best part of the distilled spirit, the heart, is taken to be used for maturation. This ensures all the flavours and compounds that the master distiller has worked to create during the distillation process are captured in the new make spirit.
The New Make Spirit
This is the outcome of the distillation process; a clear liquid with an ABV (Alcohol By Volume) percentage of around 70%. It will be the essence of the distillery and capture many of the core flavours they want their whisky to have; be that fruity and light or peaty and oily, to describe just a few. This is then put in to a cask for maturation.
Maturation
Whatever type of whisky you are drinking (whisky/whiskey/Bourbon/Rye/Tennessee) it will spend time maturing in oak barrels. This allows the spirit time to interact with the wood and take on some of the characteristics of the casks previous inhabitant. For many whiskies, the legal requirement is 3 years and 1-day to be classified as a whisky and they will be matured in an ex-bourbon, oak barrel. However, some distilleries will mature some of their whisky for much longer and they also experiment more and more using various other barrels, including ex-sherry and ex-wine barrels.
Casks at The Lakes Distillery
The Angel's Share & Devi'ls Cut
These two terms refer to distillate that is lost during maturation, with the 'Angel's Share' being evaporation that is usually around 2-3% per year. Whilst the 'Devil's Cut' is the amount of distillate absorbed in to the wood of the cask.
Finishing
Once the spirit has matured in an oak barrel, distilleries have also looked to finish the whisky in another type of barrel. This is usually a shorter period of time (6 to 18 months), using something that will impart more character and flavours on to the whisky. This has included casks that have previously held rum, sherry, IPA and peated whisky, hoping to evolve the whisky and provide a slightly different profile.
Bottling
Once the whisky has been matured and finished (if desired) it is then ready to be bottled. At this point the ABV has usually dropped to around 60% and can be put straight in to a bottle (cask strength) or water is added to bring it down to the desired ABV, which is again determined by the master distiller/blender, ensuring the whisky profile and the flavours are captured. All whisky has to be bottled at no lower than 40% ABV.
Hopefully, this post has provided you with a better understanding of how whisky is made. If you want more information, keep an eye out for future Blogs that will go in to more detail about some of the key elements of the whisky making process. For now, we hope you enjoyed this blog and that it helps you to better appreciate your next dram and gives you the confidence to join in or lead a conversation about whisky in the future.
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