What causes the smoky flavor in malt whiskey?

The smoky flavor in malt whiskey is primarily attributed to burning peat. In the production of certain Scotch whiskies, peat is often used as a fuel during the malting process, where the grains are soaked and dried. When peat burns, it emits smoke that contains various phenolic compounds. These compounds permeate the barley, infusing the grain with the characteristic smoky flavor that defines some styles of malt whiskey, particularly those from the Islay region in Scotland.

While there are other factors that can contribute to the overall flavor profile of whiskey, such as charred barrels and fermentation processes, the distinct smoke flavor associated with certain whiskies is most directly linked to the use of peat in the malting process. The use of peat smoke sets these whiskies apart within the broader category of malt whiskey, making this option the most accurate choice regarding the source of the smoky flavor.