What is a requirement for a whiskey to be labeled as single malt scotch?

For a whiskey to be labeled as single malt scotch, it is essential that it is distilled at a single distillery using pot stills. This requirement ensures that the whiskey maintains a certain level of quality and distinct flavor profile that represents the specific distillery's techniques and characteristics. Single malt scotch is made exclusively from malted barley, which must be processed and distilled in the same location, underscoring the craftsmanship and unique features of that distillery.

In contrast, other options fail to meet the criteria for single malt scotch: it should not be sourced from multiple distilleries, as that would make it a blended malt or a different category altogether. The prohibition against including different grains also clarifies that single malt refers specifically to malted barley, ensuring that the identity of the scotch is preserved. While aging for at least 3 years is a general requirement for all scotch, the question highlights the specific attribute that distinguishes single malt scotch from other types, making the emphasis on the distillation process at a single distillery and the use of pot stills crucial for its classification.