The Whisky Club's guide to Scotch, Irish, Japanese, American and Australian Whisky and the differences between them.

The Whisky Club guide to the main types of whisky

Whisky may be made from the same basic ingredients, but every country has its own rules that shape how this beloved spirit is produced and labelled. From Scotland’s strict regulations to the evolving standards in Japan and the mash‑bill laws of American bourbon and rye, these definitions influence flavour, identity, and authenticity. In this guide, we break down the official whisky definitions across the major whisky‑producing nations of Scotland, Ireland, Australia, Japan, and the United States so you can understand exactly what’s in your glass.

What is whisky? – Scotch, Irish, Australian, Japanese, American

Whisky is made around the world, but each country has its own rules and traditions. This guide breaks down the definitions of whisky in Scotland, Ireland, Australia, Japan, and the USA — helping you understand what makes each style unique.

Whisky shelves can be daunting prospects. So many bottles, so many brands, so much to consider when deciding which dram to try next. Let The Whisky Club guide you on this journey and help you distinguish your ryes from your Bourbons, your whisky from your whiskey, your Scotch from your Irish and your malts from your blends. This is The Club’s guide to the major whisky making nations.

If you'd like to learn more about exactly how whisky is made, take a look at The Whisky Club's Guide to making whisky.

Global whisky definition

Global whisky definition
Whisky is an alcoholic spirit that has:

• Been made from cereal grains*
• Distilled
• Matured in a wooden vessel for a period of time

It’s as simple as that. It’s beer (without hops) that has been distilled and matured in wood. But the way this definition is interpreted ensures that every whisky making country has its own characteristics and flavour profiles that make them distinctive.

*We should note here that many Indian whiskies are made from molasses, but for the purposes of this article, we would consider these rums.

Scotland

There are 5 types of Scotch whisky. (Single malt, single grain, blended, blended malt and blended grain.)

Scotch whisky definition

All Scotch whisky must be:

• Made from cereals into a mash that only uses enzymes created in the malting process
• Distilled and matured in Scotland
• Aged in an oak cask of no more than 700L in size for a minimum period of three years
• Be at least 40% ABV
• Be distilled no higher than 95% ABV

Single malt Scotch whisky definition

Single malt Scotch whisky:

• Follows the definitions of Scotch whisky
• Is the product of a single distillery
• Has been made from malted barley
• Distilled in a pot still in a batch process

Single grain Scotch whisky definition

Single grain Scotch whisky:

• Follows the definitions of Scotch whisky
• Is the product of a single distillery
• Fails one of the other criteria of single malt Scotch whisky

Blended Scotch whisky definitions

Blended Scotch whisky:

• Follows the definitions of Scotch whisky
• Is a blend of whisky from more than one distillery or more than one Scotch whisky type

Blended malt Scotch whisky:

• A blend of only single malt Scotch whiskies

Blended grain Scotch whisky:

• A blend of only single grain Scotch whiskies

For more information on Scotch whisky, check out The Whisky Club's guide to the Scotch whisky regions and a list of the best Scotch whiskies featured by The Whisky Club.

For access to an exclusive selection of Scotch whiskies, join The Whisky Club free today.

Ireland

Irish whiskey follows the rules for Scotch whisky very closely but with three exceptions. It must be distilled and matured in Ireland; enzymes can be added to the mash alongside those naturally occurring in the malting process; and it can be matured in casks made from any wood (but the vast majority of distillers still use oak.) There is one novel type of whiskey from Ireland, and that is Irish pure pot still whiskey.

Irish whiskey definition

All Irish whiskey must be:

• Made from cereals into a mash
• Distilled and matured in Ireland
• Aged in a wooden cask of no more than 700L in size for a minimum period of three years
• Be at least 40% ABV
• Be distilled no higher than 95% ABV

Single malt Irish whiskey definition

Single malt Irish whiskey:

• Follows the definitions of Irish whiskey
• Is the product of a single distillery
• Has been made from malted barley
• Distilled in a pot still in a batch process

Single grain Irish whiskey definition

Single grain Irish whiskey:

• Follows the definitions of Irish whiskey
• Is the product of a single distillery
• Fails one of the other criteria of single malt Irish whiskey

Blended Irish whiskey definition

Blended Irish whisky:

• Follows the definitions of Irish whiskey
• Is a blend of whiskey from more than one distillery or more than one Irish whisky type

Blended malt Irish whiskey:

• A blend of only single malt Irish whiskies

Blended grain Irish whiskey:

• A blend of only single grain Irish whiskies

Single pot still whiskey definition

Irish single pot still whiskey:

• Follows the definitions of Irish whiskey
• Is made from a mix of at least 30% malted barley, 30% unmalted barley and up to 5% other cereals
• Distilled in a batch process in pot stills

Here is a list of the best Irish whiskies featured by The Whisky Club.

To gain access to an exclusive range of Irish whiskies, join The Whisky Club free today.

Australia

Australian whisky follows many of the same rules as Scotch whisky and Irish whiskey as the technical file was a hangover from a previous incarnation of a much older more industrial industry. The new boom of craft distilling has worked well within these rules, and continue to push to define the industry in their own image as they continue to grow.

Australian whisky definition

Australian whisky must be:

• Made from cereals
• Distilled in Australia
• Matured in wooden casks for a minimum of 2 years

Japan

Since Taketsuru opened Yamazaki in 1924, the Japanese have been making their own style of whisky. As Taketsuru learned his craft in Scotland, it follows that many of the points in the 2021 definition follow the Scotch definition exactly. However, the definition is entirely voluntary making things a little murky. Luckily the big guys (Suntory and Nikka) have signed up to these conventions, and many of the smaller producers have followed suit.

Japanese whisky definition

Japanese whisky must be:

• Made from cereals into a mash that only uses enzymes created in the malting process
• Distilled and matured in Japan
• Aged in a wooden cask of no more than 700L in size for a minimum period of three years
• Be bottled in Japan at a strength of at least 40% ABV
• Be distilled no higher than 95% ABV

It is worth noting here that some whiskies we thought of as “Japanese” are a blend of Japanese and Scotch whisky (we’re looking at you Nikka from the Barrel). Although delicious, they are not technically Japanese whisky, but global blends that are blended in Japan.

The easiest way to spot a purely Japanese whisky is to look for the term “Japanese Whisky” on the label. A global blend will likely say “whisky” on the front and “Product of Japan” on the back.

America

The American whisky industry was originally shaped by the European diaspora in the 1600s and many of the most famous distillers in the USA have British or Irish routes. There are many styles of whiskey in America, each with their own set of rules and regulations. Unusually, American whiskey doesn’t have a minimum age statement, but if labelled “straight” we know it’s at least 2 years old.

Here are three of the main ones:

Bourbon definition

Bourbon whiskey must be:

• Distilled in America at no higher than 80% ABV
• Made from a mash bill that contains between 51% and 79% corn (more than 79% corn is classified as a corn whisky)
• Casked at a maximum of 62.5% ABV
• Aged in brand new casks for a minimum of 2 years. If younger than 4 the age must be stated on the label
• Bottled at a minimum of 40% ABV

Tennessee whiskey definition

Tennessee whiskey must be:

• Made in the state of Tennessee
• Filtered through charcoal in the Lincoln County process
• Follow the rules of Bourbon whisky

Rye whiskey definition

American rye whiskey:

• Made from a mash bill of at least 51% rye
• Follow the other rules of Bourbon whiskey

To access exclusive American whiskies, join The Whisky Club free today.

A growing whisky making world

There are many more nations making whisky these days, this guide is just the tip of the iceberg. Many of the new kids on the block have followed the Scottish means of single malt production, making things a little easier. Here at The Club we ensure our Members get as much information as possible about any whisky they buy, and with no obligation to purchase, you are free to dip in and out of the styles that intrigue you the most.

World whisky FAQs

What is the basic definition of whisky?

Whisky is a distilled alcoholic spirit made from cereal grains and matured in wooden casks. It’s essentially distilled beer (without hops) that has been aged to develop flavour.

What’s the difference between Scotch and Irish whiskey?

Both are similar, Scotch whisky must be made in Scotland and Irish whiskey must be made in Ireland. In terms of production, Irish whiskey allows added enzymes in the mash and can use any type of wood for maturation whereas Scotch whisky production can only use enzymes from the diastase of malt and can only use oak casks for maturation.

Why is Japanese whisky sometimes not really Japanese?

Some whiskies labelled as Japanese are actually blends of Scotch and Japanese whisky. Look for the words “Japanese Whisky” on the label to ensure it meets the voluntary 2021 standards.

What makes Bourbon different from other whiskies?

Bourbon must be made in the U.S. from at least 51% corn, aged in new oak casks, and distilled below 80% ABV. It’s known for its sweet, rich flavour.

Is Tennessee whiskey the same as Bourbon?

Almost... Tennessee whiskey follows all the Bourbon rules but must also be made in Tennessee and filtered through charcoal (the Lincoln County Process). So technically, all Tennessee whiskies are Bourbons but with an extra filtration stage and a tight geographical area of production.

What is pure pot still Irish whiskey?

It’s a traditional Irish style made from a mix of malted and unmalted barley, distilled in pot stills. It offers a creamy, spicy character unique to Ireland.

How long must whisky be aged?

It varies by country:

• Scotland, Ireland, Japan: Minimum 3 years
• Australia, USA (if labelled “straight”): Minimum 2 years

For more information on how whisky is aged, check out The Whisky Club's guide to casks.

Is whisky always made from barley?

Not always. While Scotch and Japanese whiskies use malted barley for enzyme creation, American whiskies like Bourbon and Rye use corn and rye respectively as their main cereals, and don’t need to use barley, but many do. Likewise, Irish and Australian whiskies will mostly use barley, but there is no regulation that says they have to for certain styles of whisky.

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