The base ingredients for Scotch are simple: water, yeast, and grain. By federal regulation, there may be no additives, and distillation and barrel aging must happen in Scotland.

Malted barley is the traditional choice of grain, although wheat and rye are also used. This composition, along with whether it's blended, delineates Scotch into its main types.

Scotch malt whisky is the most regulated sub-style, necessitating that the spirit is made from exclusively a malted barley mash distilled in a pot still.

Single malt bottles are among the most expensive due to how it showcases its ingredients. Locally sourced malts mingle with local water and yeast to transmit regional qualities.

In the 19th century, Scotch was opened to more ingredients including rye, corn, and wheat, with malting an optional step. As a result, grain whiskies dominate the Scotch market.