Retronasal olfaction is the process of smelling volatile aroma compounds through the back of the throat as they travel from the mouth to the nasal cavity during tasting and swallowing. It is a major reason why aroma contributes so much to what people experience as flavour. The term is used in wine tasting, food science and sensory evaluation.
When wine is in the mouth, volatile compounds are released from the liquid and move through the nasopharynx toward the olfactory receptors in the nose. These aromas are perceived internally, rather than by sniffing the wine through the nostrils. The brain combines retronasal smell with taste, texture, temperature and other sensations to create the overall flavour experience.
Orthonasal olfaction is smelling wine through the nostrils before tasting. Retronasal olfaction occurs as aromas travel from the mouth to the nasal cavity while tasting. Both are important in a structured wine assessment.
Take a small sip and allow the wine to coat the mouth. Some tasters gently draw a little air through the lips to release more volatile compounds, but this is not essential and should be done discreetly in professional service. Notice whether fruit, floral, herbal, spice or savoury aromas become more pronounced after the sip.
Example: a Riesling may show lime and floral notes on the nose, then reveal additional citrus, stone-fruit or mineral impressions retronasally as it is tasted.
Chef’s note: much of what guests describe as flavour is actually aroma. This is why congestion can reduce the ability to appreciate wine and food.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
