Like most other labels, the Scotch whisky label combines law, tradition, marketing, and whim, and may therefore be difficult to understand. Because of variations in language and national law, the following is a rough guide:
If a label contains the words “single malt” (sometimes split by other words e.g., “single highland malt”), the bottle contains single malt Scotch whisky.
"Vatted malt", "pure malt", or "blended malt" indicates a mixture of single malt whiskies. In older bottlings pure malt is often used to describe a single malt (e.g. “Glenfiddich Pure Malt”).
The label may identify the distillery as the main brand or as part of the product description. This is most likely the case for single malt. Some single malt whisky is sold anonymously or with a fictitious brand name. This can be at the request of the distillery or producer to protect their brand. An example of this is single cask whiskies independently bottled by companies such as The Scotch Malt Whisky Society, who use a numbering system as a part of their agreement with distillers. This does not indicate quality, but successive bottles may be completely different as each individual cask imparts unique qualities to the spirit. The only reliable way to identify the distillery is to use a reference.
Alcoholic strength is listed in most countries. Typically, whisky is between 40% and 46% abv. A lower alcohol content may indicate an “economy” whisky or local law. If the bottle is over 50% abv it is probably cask strength.
Age is sometimes listed as well. For example, if a bottle is labelled as 12 years old the youngest whisky in the bottle has been matured in cask for at least 12 years before bottling.
A year on a bottle normally indicates the year of distillation and one cask bottling, so the year the whisky was bottled may be listed as well. Whisky does not mature once bottled, so the age is the difference between these two dates; if both dates are not shown the age cannot be known from the bottle alone.