The short answer
Single Malt Scotch comes from a single distillery. It's distilled from malted barley, in stills called pot stills. Single here refers to the one distillery, not a single cask.
Multiple casks are possible
A bottling can contain whisky from various casks from the same distillery. This is entirely compatible with Single Malt. Single Cask, on the other hand, refers to a bottling from one individual cask. The two terms answer different questions.
The word single refers to the origin, not the quantity. It means: what's in the bottle comes from a single distillery. How many casks were combined to make it is left open by the term. For many bottlings, it's several. This helps keep a distillery's character consistent over the years.
Single Cask answers the other question, namely the number of casks involved. Both pieces of information aren't mutually exclusive and can appear together on a label. If there's no mention of a single cask, that's not a statement about quality. That question simply wasn't asked here.
No automatic quality ranking
Single Malt and Blend can't be compared like school grades. Find a style you like, and read the full designation. Even a Single Malt can taste light or bold, smoky or not smoky at all.
A practical exercise: compare two bottlings with similar strength and different cask descriptions. This gives you a feel for the style. Buying based on the word Single won't get you there. Write down the entire product name, since the distillery name alone often isn't enough to find it again.
It helps to go beyond the distillery name when taking notes. Write down the full designation, the strength, any cask information, and, if available, a batch reference. A distillery releases different bottlings over the years. Two of them can differ more noticeably than two whiskies from entirely different origins.
When comparing two bottlings, use small amounts and let both glasses sit side by side. Your first impression often shifts after a few minutes. If you go back to the first glass afterward, the difference usually becomes clearer. Tasted one after the other without pausing, it's easy to miss.
Comparing Single Malt, Single Cask, and cask strength
These three terms are the ones most often confused. Each answers exactly one question, and none of them promises you a particular taste.
Remember this above all: Single Malt tells you something about the distillery, Single Cask about the number of casks, and cask strength about the strength at bottling. Keep these three apart clearly, and you'll read a label correctly in seconds.
| Term | Question it answers | What doesn't follow from it |
|---|---|---|
| Single Malt Scotch | Malt whisky from one distillery | Just one cask, or automatically better taste |
| Single Cask | A single cask as the origin | A particular alcohol strength |
| Cask Strength | Information about bottling strength | A single cask |
How to recognize a Single Malt
Take a moment at the shelf to look at the front of the bottle. That's where the category is stated, often in smaller print beneath the name. Everything else is usually found on the same label: the strength, cask information, and occasionally a note that the whisky comes from a single cask.
If two bottles from the same distillery are side by side, compare the details listed under the name. That's exactly where the difference lies that you'll notice later in the glass. The distillery name alone won't help you much when buying again, since it applies equally to very different bottlings.
Single Malt doesn't mean a single cask
The most persistent misunderstanding: that single stands for a single cask. It stands for a single distillery. Almost as common is the assumption that the category says something about rank. It tells you about origin and raw material, namely malted barley, distilled in pot stills.
Smokiness is also often attributed to the category. Whether a Single Malt tastes smoky or not at all has nothing to do with the term. It tells you just as little about how powerful the bottling will feel in the glass. If you want to know that, read the strength statement and the cask description.