Simply put, whisky is an aged spirit distilled from grains. We have a tendency to overcomplicate spirit production – but when it comes down to it, whisky is made from three ingredients: water, grain and yeast.
There are differing production requirements depending on the style and type of whisky. Often these are defined in local regulations. Far from being boring, these essentially ringfence the characteristics and styles of the whiskies that we love. They’re also usually rooted in long traditions, speaking to the rich heritage of these spirits. Ever wondered why bourbon tastes different to single malt Scotch, which then tastes different to Irish whiskey? You’re in the right place!
Peat, while not an ingredient in whisky itself, can be used as part of the production process to impart smoky, earthy aromas into the grain. We won’t talk about it in detail here, but it can be seen as a ‘material’ used in whisky production.
What we will explore are all the major styles of whisky produced globally: what they’re made from and why they taste the way they do. Let’s start with Scotch whisky!
What is Scotch whisky made from?
There are five main different styles of Scotch whisky, all – perhaps obviously! – made in Scotland, UK. Every type must be made from either malted barley or other whole grains, with mashing, fermentation and distillation all happening at the distillery.
It then must be aged for a minimum of three years in oak barrels – only water or E150a caramel colouring can be added. All maturation and bottling must happen in Scotland, or it simply cannot be called Scotch.
Single malt Scotch must be made from 100% malted barley, at one distillery, with a type of stills called pot stills used for distillation. These are like giant copper kettles – it’s a batch process, and it can take quite some time. The Macallan, Glenfiddich and Glenlivet are all single malt whiskies.
Single grain Scotch whisky is again made at just one distillery – but this time you can use malted barley and other whole grains. It will typically be made using column stills.
Blended Scotch whisky is made from a recipe of at least one single malt blended with at least one single grain. Typically you’ll have lots of distilleries combined together. This is by far the biggest category of Scotch whisky by volume. Johnnie Walker is a blended Scotch brand.
Blended malt Scotch whisky is a combination of single malts from two or more distilleries, while blended grain Scotch whisky – incredibly rare – is a blend of at least two single grains.
Producers across Scotland are increasingly experimenting with recipes made using rye and other whole grains.
What is Irish whiskey made from?
Irish whiskey is experiencing a vibrant revival, with lots of new distilleries popping up across the island. Some of its rules are different to that of Scotch whisky, and as such it can be made from different ingredients in different ways.
While they are rarely seen in practice, there’s a quirk in the law that permits Irish whiskeys to be aged in woods other than oak. Regardless, all Irish whiskeys must be aged for a minimum of three years. Broadly speaking, there are four Irish whiskey styles.
Irish pot still whiskey is made from a recipe – or mash – that includes at least 30% unmalted barley, 30% unpeated malted barley, and other cereals, too. By law, it will be made using double- or triple-pot still distillation. Redbreast is a great example of an Irish pot still whiskey.
Irish malt whiskey uses 100% malted barley, which can be peated or unpeated, and is then distilled using pot stills. Teeling and Connemara made Irish malt whiskeys.
Irish grain whiskey is made from a recipe of unmalted grains and up to 30% malted barley, and it must be distilled in a column still.
Irish blended whiskey is a combination of two or more different types of Irish whiskey. Jameson is an ever-popular example of an Irish blended whiskey.
What is American whiskey made from?
American whiskey is perhaps the most diverse of all whiskey styles when it comes to raw materials. Most get their bold, characteristic flavours from their mash bills – or grain recipes.
These are at the heart of many expressions, and, far from keeping them a secret, many producers will proudly shout about the proportions of their grains. Similar to Irish whiskey, American whiskey producers are in the midst of a huge craft distilling revival. Excitingly, American single malt is on the cusp of becoming a legally recognised category, and there’s a huge amount of innovation in this area.
Age statements differ enormously in the US. While these examples can’t be legally recognised as ‘whisky/whiskey’ in the EU or UK, white whiskey, or white dog, are fascinating examples of unaged spirit that are popular across the US.
Another fascinating quirk to note with American whiskey: blended styles here can include a portion of neutral spirit. Again, because this is unaged spirit, these bottlings wouldn’t be called ‘whiskey/whisky’ in the EU or UK. In the US, ‘straight’ whiskeys have been aged for at least two years, while whiskeys without an age statement have a guaranteed age of at least four years.
Bourbon is made from a mash bill of at least 51% corn, and it has to be matured in brand new charred oak barrels. The rest of the mash bill can be made from any other combination of grains! Some bourbons have a high rye content, some have a higher wheat content.
This will have a tremendous influence on flavour. A key difference to Scotch whisky is that it is not allowed to be finished with any added colour. No caramel or E150a here! Buffalo Trace, Basil Hayden’s and Four Roses are all examples of bourbon whiskeys. A fun note – bourbon can be made anywhere in the US!
Rye whiskey is made to exactly the same requirements as bourbon whiskey – except that all-important mash bill recipe must include a minimum of 51% rye. Many producers, for example, Knob Creek, Michter’s and Bulleit, make rye whiskeys as well as bourbons.
Wheat, malt and rye malt whiskeys are all made to the same requirements as bourbon, with the named grain legally required to make up at least of the mash bill.
Corn whiskey is again similar to bourbon, but the mash bill must have at least 80% corn. Interestingly, corn whiskey does not have to be aged in oak – but if it is, used or uncharred new oak can be utilised.
Tennessee Whiskey is made to the same rules and standards as bourbon – at least 51% corn in the mash bill, brand new charred oak barrels, and with no natural colour. There is an additional stage called the Lincoln County Process. The spirit must be filtered through maple charcoal prior to maturation, giving a sweeter, lighter style. As the name suggests, Tennessee whiskeys can only be made in the state of Tennessee. Jack Daniel’s and Uncle Nearest are two examples of Tennessee whiskeys.
American single malt is – yet! – to be fully defined in law, but the draft proposals state that it must be made at one US distillery, from mash made using 100% malted barley, aged in oak barrels, and with no colour or flavourings. At this point, no minimum age has been specified. Westland is an example of an American Single Malt distillery.
What is Japanese whisky made from?
Japanese whisky marks its 100th anniversary in 2023! Inspired by the techniques and heritage of Scotch whisky, it broadly follows the same production standards and labelling terms, but these aren’t defined in law.
Interestingly, a group of producers known as the Japanese Spirit and Liqueur Makers Association (JSLMA) clubbed together and in 2021 announced that a self-governing set of standards would come into play.
This was in response to a growing trend for some (not all!) producers to buy in malt and grain whisky from Scotland, blend it with whisky made in Japan, and bottle it as Japanese whisky. In short, the new rules mean that all the steps in the whisky-making process must have taken place in Japan, from mashing through to maturation. Japanese whiskies must be then aged for at least three years and bottled in the country.
While the rules came into effect from April 2021, not every producer in Japan is a member of the JSLMA. It may well be that some Japanese whisky made using Scotch spirit, may still continue to be labelled as Japanese whisky.
Japanese whisky makers often produce malt whisky and grain whisky at the same site.
Yamazaki and Hakushu are examples of Japanese single malts, while Nikka and Hibiki are celebrated Japanese blends.
What is Canadian whisky made from?
While Canadian whisky does have some legal requirements, there are no restrictions on the types of grain it can be made from. Essentially producers make two types: a base whisky, usually made from corn, although sometimes wheat is used; and a flavouring whisky, typically made using rye. Producers then add varying proportions of their flavouring whisky to their base spirit and voila! Canadian whisky is created.
Some interesting points to note is that Canadian whisky can in fact be flavoured by any spirit of wine, and there aren’t restrictions on the proportion that can be added. Nor do producers have to adhere to a minimum proportion of rye if making Canadian Rye Whisky. But! If you’re going to export your Canadian whisky, the ‘flavouring’ part must account for at least 9.09% of the recipe. Confusing? Yes. Tasty? Very often.
As in many other countries, craft distillers are now popping up across Canada. It will be exciting to see how they change the shape of the industry.
Other world whiskies and how they are made
Today, whisky is made all over the world. Many regions don’t have restrictions around the type of grains that can be used in production, or indeed what could be added into a bottle post-maturation.
Whiskies are being made from grains like quinoa, buckwheat, oats and even millet. Each brings its own flavour profile and character to the whisky party.
We haven’t even touched on flavoured whiskies here – spirit drinks made with flavourings and essences. In many markets, including the UK, it’s not permitted to call them a ‘whisky’, but they can be excellent and there is a place for them in the market.
It’s an incredibly exciting time to be drinking whisky. What will you taste next?!