Many factors affect the way a coffee is perceived by the senses, and therefore these factors also affect the degree to which a coffee is appreciated. These factors include: Your immediate surroundings : Location eg: sterile laboratory or in a factory Nearby odors/aromas eg: perfume, smoke, food Degree of lighting Noise and other outside distractions Air current movement ie: diverts aromas from the nose Both the ambient temperature and the temperature of the coffee Color of surroundings ie: affects mood Differences in personal perception Concentration Shape and material of cup and/or spoon How you move the coffee in your mouth How long you keep the coffee in your mouth Whether you swallow or expectorate The time of day Your expectation (this is exaggerated if you have seen the label, beans, bag, etc) Your general health When you last ate and what it consisted of Your coffee tasting proficiency.
The most important evaluation of a coffee is performed by ones olfaction. Olfaction is what allows one to sense aromas and occurs when air carrying the aromas passes over the receptors which are primarily located behind the bridge of one's nose. There are four major stages in the olfaction evaluation of a coffee, the dry aroma, the cup aroma, the nose, and the aftertaste. The dry aroma (aka. the fragrance) is the smell of the roasted and ground coffee beans. It is composed of compounds that are gaseous around room temperature, while the other 3 stages are from aromas turned gaseous only at the elevated temperatures associated with brewing. The cup aroma is the smell of the coffee brew. It is formed from the aromatic compounds leaving the surface of the brew. The nose is composed of the aromas that are released from the brew when it is taken into the mouth. Finally, after the coffee is swallowed, residue remains on the palate, the residue then emits vapors which are then sensed by olfaction, resulting in an aftertaste.