Orthonasal Olfaction

Orthonasal olfaction refers to scent perception through the nostrils during inhalation — the primary pathway for detecting cannabis aromas in fresh flower, dried material, or smoke. This contrasts with retronasal olfaction, where volatile compounds reach olfactory receptors via the back of the throat during consumption. In cannabis evaluation, orthonasal assessment focuses on direct aroma detection from the plant material itself, capturing terpene profiles before combustion or other processing alters the volatile compound composition. Breeders and researchers commonly use orthonasal testing as a baseline method for comparing strain phenotypes and tracking terpene stability across generations.

Breeders working in aroma selection typically rely on orthonasal evaluation during phenotype hunts to identify individuals with distinct or potent volatile profiles. Consistent orthonasal markers help establish stable aroma characteristics within a line, supporting breeding programs focused on terpene expression.