Which chemical compound is responsible for the distinct flavor of aniseed spirits?

The distinct flavor of aniseed spirits is primarily attributed to anethole. This compound is a significant flavor component found in star anise and fennel, contributing a sweet, aromatic quality that is characteristic of products like pastis and ouzo. Anethole has a natural affinity for the palate and is responsible for the unmistakable licorice taste that defines these spirits.

Menthol, ethyl vanillin, and cinnamaldehyde do play roles in the flavor profiles of various spirits and liqueurs, but they do not contribute to the signature flavor of aniseed. Menthol provides a cooling sensation and is commonly associated with mint, while ethyl vanillin imparts a vanilla flavor, often used in sweeteners and flavorings. Cinnamaldehyde delivers a spicy cinnamon flavor, commonly found in certain spiced spirits. None of these compounds possess the specific aromatic qualities associated with anise, making anethole the correct choice for defining the flavor of aniseed spirits.