Which of the following is a characteristic of single malt whisky?

Single malt whisky is defined as a whisky that is produced at a single distillery and is made from 100% malted barley. This characteristic highlights the unique attributes that each distillery imparts to its spirit based on its specific production methods, regional influences, and maturation processes. By being produced in a single distillery, the whisky retains a distinctive flavor profile that is representative of that location and its traditions.

The other options do not accurately describe single malt whisky, as they pertain to different types of whisky or production methods, which is why they do not fit this definition. This distinction is crucial for understanding the classification and appeal of single malt whiskies in the broader spirits category.