The Differences Between Irish, Scotch and American Whiskeys

May 2, 2022

While Irish whiskey is widely accepted as being the original whiskey with its origins dating back to the 12th and 13th century and the first recorded mention of Aqua Vitae (the water of life/uisce beatha) in 1324, the roaming Irish brought their distilling skills to foreign lands through their travels and emigration over the centuries.

Today, whiskeys from Taiwan to Tasmania and Tennessee can trace their roots back to Ireland yet each country and style of whiskey around the world has evolved, determining their own rules, definitions and ingredients. In this article, we look at what makes whiskey Irish, Scotch or American.


Irish Whiskey

Irish Whiskey Characteristics



Must be a product of Ireland (fermented, distilled, matured on the island of Ireland) however it may be bottled outside of Ireland as long as it follows strict labelling criteria

Often triple distilled (although this is not written in stone). New Irish whiskeys are also being produced as double distilled. Grace O Malley Irish Whiskey uses double distilled malted barley

Maturation & ABV

Matured for a minimum of 3 years to no more than 94% Alcohol by Volume (ABV) and bottled at no less than 40% ABV


Most Irish whiskeys aren’t smoked/peated though this is changing with the introduction of new peated whiskeys . An example of peated Irish whiskey is Connemara


Irish Whiskey Classifications

Single Malt

Single Malt Irish Whiskey is made from 100% malted barley by a single distillery in a pot still. An example of Single Malt Irish Whiskey is Sexton Single Malt.

Single Grain

Single Grain Irish Whiskey is particularly light in style. Made typically from corn or wheat and no more than 30% malted barley, Grain Whiskey is produced in column stills by a single distillery. Kilbeggan 8 Year Old Single Grain is an example.


Blended Irish whiskey constitutes 90% of all Irish Whiskey production and is a blend of two or more other styles of Irish whiskey. Jameson is the most well known blended Irish Whiskey and consists of a blend of single pot still and single grain whiskeys.

Single Pot Still

Single Pot Still Whiskey is a mixture of both malted and unmalted barley (and up to 5% other grains such as oats, wheat, rye or corn) distilled in a pot still from a single distillery giving way to a creamier, mouth-coating texture. Redbreast is one of the best known examples of a Single Pot Still Irish Whiskey. 



Scottish (Scotch) Whisky

Scotch Whisky Characteristics



Must be produced in Scotland (fermented, distilled, matured in Scotland) from water and malted barley to which only whole grains of other cereals may be added

5 main areas where Scotch can be produced in Scotland – Lowlands, Highlands, Speyside, Campbelltown and Islay/Island regions with over 130+ active distilleries

Maturation & ABV

Must be matured for at least 3 years in oak barrels, distilled to no more than 94.8% ABV and bottled at no less than 40% ABV 


Typically double distilled though not essential. Whisky spelt without an “e”.


Scotch Whisky Regions

The Highlands area has 39 distilleries with a diverse flavor profile – from light, delicate and floral flavors through to the hearty and robust style many associate with this part of the country. Examples include Dalmore 18 Year and Macallan ‘Classic Cut’ 2020

The Speyside area encompasses about 50 distilleries. Strathspey is the heart of the Scotch Whisky business, producing the vast majority of whisky used in blends and also sold as a single malt. Glenfiddich 12 Year Old is an example

The Islay region, boasting 9 distilleries, is renowned for producing peated/smoked whisky a process done by drying the malted barley over a peat fire. Examples include Ardbeg & Laphroaig

The Lowlands is the most prominent region for Scotch distillation and is the home of the blend as well as large quantities of grain whisky. Auchentoshan Three Wood Lowland Single Malt Scotch Whisky – now there’s a mouthful!

Finally the Campbelltown region, once home to 34 distilleries, now boasts a modest 3 distilleries. Glen Scotia 15 Year Old and Springbank 1962 are examples.


Scotch Whiskey Classifications

Similarly to Irish Whiskey, the Scotch category is broken down into Single Malt Scotch (The Glenlivet), Single Grain Scotch (Haig Club Single Grain Scotch Whisky) and Blended Scotch Whiskey (Chivas Regal)



American Whiskeys & Bourbons

Every bourbon is an American whiskey but not every American whiskey is a bourbon. What this means is that unless you tick all the boxes of the stringent criteria that bourbon must adhere to, it cannot legally be called a Bourbon and therefore is only considered an American Whiskey as it is a product of America (fermented, distilled, matured in America).




Used to only be able to legally make bourbon in Kentucky and Tennessee. Over the last few decades, the stipulation on this requirement has become lax due to the increase in demand for bourbons and now can legally make bourbon anywhere in the US


Must use virgin American white oak barrels that are singly charred. These barrels can never have had any other liquor in them before, therefore technically cannot be used to make bourbon again. This is why so many bourbon barrels are used for maturing Scottish and Irish whiskeys

Mash Bill

Have at least 51% minimum corn in the mash bill. The remaining 49% comprises of other cereal grains such as wheat, rye or barley. This corn-forward mash bill coupled with the naturally occurring component of vanillin in bourbon barrels mean that bourbons tend to be sweeter than Irish Whiskeys or Scotches 

Maturation & ABV


Matured for at least 2 years to make a straight Bourbon

Distilled to no more than 80% ABV in 50-100 gallon stills and often bottled between 40-60% ABV



No blending or additives – except water to reduce it to bottling proof – is allowed in bourbon. Unlike in Scotch or Irish whiskeys where caramel coloring is permitted

“Bottled in Bond” bourbon must have been made using a single distillation at one distillery, aged in a federally bonded warehouse for a period of at least four years and bottled at 50% as originally defined in the 1987 Bottled-in-Bond Act


Many examples of bourbons exist today –Jim Beam, Woodford Reserve, Maker’s Mark, Four Roses, Knob’s Creek, Michter’s etc.


Rye Whiskey

Rye Whiskey essentially has similar criteria governing the labelling of the product as bourbon does but as the name suggests, Rye Whiskey must be distilled from a mash bill containing at least 51% rye within the United States. Rye must also use charred new American white oak barrels for a minimum of two years. Distilled in small batches in 26-gallon custom-built stills for an authentic historically accurate Prohibition-era taste at no more than 80% ABV. It then spends 24 months aging in new 15-gallon charred white oak barrels. Free from additives with no artificial flavors. Some examples include Redemption Rye Whiskey and WhistlePig 10 Year 100 Proof Rye Whiskey.


Tennessee Whiskey

The distinct difference in Tennessee Whiskey is due to a unique filtration process in which the whiskey is allowed to slowly drip through 10 feet of sugar-maple charcoal. Known as the “Lincoln County Process,” it can take up to two weeks to run one batch through the charcoal. The whiskey is then transferred to a charred barrel for aging for a minimum of two years. It is common to pick up a charcoal taste in Tennessee Whiskey. The most well-known example of Tennessee Whiskey is Jack Daniels.