What defines single grain scotch?

Single grain Scotch whisky is defined by being distilled at a single distillery using grains other than just malted barley. While Scotch whisky can incorporate various grains, including corn and wheat, the term "single grain" specifically emphasizes that the whisky comes from one distillery and utilizes these non-malted grains in its production.

This designation distinguishes single grain Scotch from single malt Scotch, which is produced exclusively with malted barley at a single distillery. Therefore, the focus of single grain Scotch on the combination of distillation location and the type of grain used is what makes option C the correct choice. Understanding this aspect is essential for grasping the broader classification within Scotch whisky and the different production methods involved.