What Are the Differences Between Single Malt Whisky, Blended Whisky, Single Grain Whisky & Single Cask Whisky?

I once asked a colleague if he liked single malt whisky. He replied “Yeh, single malts, double malts, everything!”. I paused, and he said “I said something wrong, didn’t I?”. “Yes.” I replied “But it doesn’t matter. If you like whisky, lets drink some and talk about it.”

 A week later, we had a proper session, and got stuck into whiskies of different types, mostly single malt Scotch whisky and blended Scotch whisky. It was clear he had a well-developed palate and knew some of the brands, he just didn’t really know the terminology behind it all. Sometimes, people are afraid to ask, so they say nothing until they say something clearly wrong. My advice is to just ask – we are mostly a friendly bunch of people. But if you really don’t want to ask you can just read this and you’ll be well informed. 

What exactly does Single Malt Whisky mean?

‘Single Malt’ has two parts to it. Single, and malt. But the first part – ‘single’ – does not refer to the second part – ‘malt’. Single malt does not mean “made with one type of malt”. The two terms refer to separate things.

Single 

means the whisky is made at one single distillery. If I have a cask full of one whisky and add a single drop of whisky from another distillery, it can no longer be called a single malt, because it is the product of more than one distillery.

Malt 

means the whisky has been made from 100% malted barley, with no other grains allowed. No corn, no wheat, no rice, no rye, no unmalted barley.

And there’s more to it 

There’s a little bit more to it, that is not reflected in the name. Single malt whisky must be distilled in a pot still, rather than a continuous still. In other words, it must be made through batch distillation. There’s no rule about how many times it must be distilled in a pot still, but practically speaking it must be distilled at least twice.

Other Whiskies

Whisky that is made from other grains or made in a continuous column still is called grain whisky and if it is also made in a single distillery, it is called ‘single grain’ whisky. Note, again, that ‘single’ refers to the number of distilleries involved, not the grains. A ‘single grain’ whisky usually includes more than one type of grain.

So assuming the whisky is made in one distillery:

• 100% malted barley + pot distillation = ‘single malt whisky’
• Other grain bill + continuous column distillation = ‘single grain whisky’

This leaves two other combinations:

• 100% malted barley + continuous distillation
• Other grain bill + pot distillation

Both of these are also considered ‘single grain whisky’ as neither meets all the criteria for single malt whisky.

Once we’ve made single malt whisky and single grain whisky, we can mix them in different ways to create other categories, which is referred to as blending:

• Mix one or more single malt whiskies with one or more single grain whiskies = blended whisky
• Two or more single grain whiskies with no single malt whisky = blended grain whisky
• Two or more single malt whiskies with no single grain whisky = blended malt whisky

Other terms

You may encounter other terms such as ‘pure malt whisky’ or ‘vatted malt whisky’. Japanese whisky in particular uses the term pure malt whisky. These terms are no longer permitted by the legislation that governs Scotch whisky, though you may find them written on some old bottlings. They were banned as they were considered misleading.

You see, the term ‘single malt whisky’ has not been legally defined for all that long. Up until the 1980s there were bottlings called ‘pure malt’ that would fit today’s definition of single malt whisky, and other bottlings of ‘pure malt’ that would fit today’s definition of blended malt whisky. Both are of course ‘purely’ malt, but they are different things. Terms were changed to avoid confusion, and some people are frankly still unhappy about it.

For the record, when Japanese whisky says ‘pure malt’ today, they mean blended malt, but that old 1970s bottle of Glenfiddich your grandad hid in the back of the cupboard that says ‘pure malt’ is a single malt whisky.

So, single malt whisky & blended whisky are different, right?

Hold on to your hats.

Whisky is aged in casks, and in many countries the maximum cask size is 700 liters or less, so it is effectively aged in very small batches. Most distilleries don’t bottle in very small batches, they bottle in big batches, so they must mix many casks together first. In terms of common language usage, you could say this is ‘blending’, and that’s an argument that some people like to make on occasion. I find it a very pedantic and unhelpful argument, because obviously mixing casks from the same distillery is different to mixing casks from different distilleries and it’s easier to understand if we use different terms. I prefer to refer to mixing casks within a single distillery as ‘vatting’ rather than blending. Of course, this is not helped by the esteemed title of Master Blender, which is a often bestowed on people who mix together different casks from the same distillery to create single malts.

However, there is something called ‘single cask whisky’, which is taken from just one cask and is never vatted or blended. Except when it is sometimes vatted or blended, but that’s a story for another time.

Did I miss out any other whiskies? You can read more more about me here or click on my social media icons below to share your thoughts.