Sometimes a man is born for a specific task. For Caspar MacRae, it is to answer this question: What’s the difference between all of the types of whiskey?

He’s the Global Brand Director for Irish and American Whiskies at William Grant & Sons, plus he was born and raised in Scotland. He set us straight with a little help from Tullamore D.E.W. Irish Whiskey’s master blender Brian Kinsman and global brand ambassador John Quinn. And, while Tullamore has been doing Ireland proud since 1829, these gentlemen appreciate whiskey in all its forms and spellings. 

We’ll start with the Europeans and work our way over to America and keep going for brief stopover in Japan. Hey, it’s a global beverage.

As Scottish, Irish and American distillers experiment and innovate more and more, there is more and more overlap between these different branches of the same tradition.

A Mix of Mashes.
“Essentially, we are all trying to distill and mature a brewed mash of malted grain and water,” says Quinn.

Kinsman breaks down the national divide…

Scotland: “Single malt is 100 percent malted barley,” while “grain whisky is a combination of malted barley and any other whole grain cereal, typically wheat or maize.” He notes that the “use of peated malt is commonplace” and even “unpeated whiskies often have trace levels of peat, adding some additional flavor character.” This is a big reason the Scottish version tastes so smoky.

Ireland: Again, single malt is pure malted barley and grain is the malted barley/cereal combo. Here’s where the separation starts. Unlike the Scots, the Irish have pot still, a “combination of malted and unmalted barley.” For those unfamiliar, Quinn explains it this way: “Pot still whiskey was invented in the late 1700s when the English King decided to apply a new ‘Malt tax’ and the Irish decided if they used less malt they’d pay less tax—the resultant whiskey could not be called malt whiskey (as here we must use 100 percent malted barley).” So suck on that, Prince Charles.

Differing Distillations.
“In Scotland it’s typically distilled twice and in Ireland it’s typically distilled three times,” says Quinn. As a result, MacRae observes the Irish version “may be a little lighter in the body and smoother on the finish,” while Kinsman describes double-distilled Scottish offerings as a “heavier, more robust distillate.”

Quinn sums up the taste variation: “Scotch is usually more earthy and robust, while Irish is described as fresher, fruitier and is often said to be smoother.”

The Spelling.
Here’s an easy way to remember: Ireland’s spelling of “whiskey” has an “e” in it, like the word “Ireland,” while Scotland, like its whisky, does not. America has embraced Ireland’s spelling so we have “whiskey,” while Japan and pretty much the rest of the planet chose to follow Scotland’s lead.

Now it’s time to go to the other side of the Atlantic…

Enter America.
Kinsman chose to focus on bourbon in discussing the mash, which “needs to be greater than 51 percent corn with other cereals including malted barley, wheat and rye.” MacRae notes that the Irish and Scots “mature our whiskey in cool warehouses in previously used oak casks,” while Quinn says that Americans use “new oak for the barrels” and “place them in warm warehouses.” MacRae credits this technique with imparting “a lot of flavor in not much time.”

Quinn points out this difference in barrel approaches results in a nice synergy between the nations: “Ireland and Scotland, we are happy to buy the used bourbon casks as they offer us a different flavor return, vanilla in direction, and the American whiskey producers are very happy to have ready-made customers for these barrels as they are not allowed use them a second time.”

What’s the difference in flavor for the American approach? Quinn says it produces “a lot of sweet and yet tannic flavours” and MacRae notes they tend to be “big and bold” and the use of corn gives it “a sweet, oily note.”

And now to complete our journey…

Japan Joins the Party.
Japan began making whisky commercially in the 1920s. To put this is in perspective, Tullamore was turning 100 as they were just getting started. As you can tell from the spelling, Scottish whisky was the inspiration and they tend to use its production methods, to the point that they’re known to import peated barley.

That said, in recent years the Japanese version has come into its own with a reputation for being luscious and silky. The moment most often cited in its rise to American/global popularity is Jim Murray’s Whisky Bible 2015 naming the Yamazaki Single Malt Sherry Cask 2013 the best in the world, making Scotland even more surly than it normally is. (Also, as with most things, props must be paid to Bill Murray.)

Now that we’ve established the lines, you can start blurring them. MacRae reports, “As Scottish, Irish and American distillers experiment and innovate more and more, there is more and more overlap between these different branches of the same tradition.”

We’ll debate adding water or rocks next time.