Sensory analysis mistakes, why do we make them?

Although our senses are very powerful tools, sometimes even more sensitive than state-of-the-art scientific equipment, if not used correctly they lead us into error and return wrong answers during our evaluation sessions.

There are many traps which we need to avoid in order to carry out proper sensory sessions. We can group them into three main blocks

  • Physiological Errors
  • Psychological Errors
  • Other minor mistakes

Each one of these categories includes some of the most frequent evaluation errors that we have to keep in mind in order to obtain the best performances.

Physiological Errors

This type of sensory analysis mistake derives from our natural response to sensory stimuli. Let’s get acquainted with them.

Among the physiological errors we can list

  • Adaptation error: occurs when we are subjected for a long time to a same stimulus. This leads to a decrease of sensitivity towards a stimulation. For example, when we enter an environment with a characteristic odour, after some time we no longer perceive it. People who have the habit of eating salty foods feel the need to increase gradually the amount of salt to sense the same intensity of the stimulus.

  • Increase or decrease error: occurs when two stimuli interact with each other providing a greater (or lesser) total intensity than the two single stimuli. For example, a fresh water solution is perceived sweeter if consumed in the presence of the smell of vanilla (increase between the senses). Similarly, sugar in coffee reduces the bitter intensity of caffeine (decrease in taste).

  • Threshold error: it is due to the different threshold of perception (sensitivity) that individuals have, so that two people with very different sensitivity can associate a different intensity to the same stimulus.

  • Pathological errors: occur when the subject has temporary or permanent physiological deficits, that make him/her unable to perceive some smells (anosmia), some flavours (ageusia), some colours (colour blindness) or other sensory stimuli.

Psychological errors, don’t let your brain fool you!

Psychological errors are related to the way our brain processes sensory information. The most commonly found are

  • Error of expectation: derives from previous knowledge that the judge may have about the product under evaluation. For example, a trained cheese judge, will tend to “seek” a pungent note (propionic or acetic) in cheeses that have large holes (such as Emmenthaler cheese) as these two elements, the presence of holes and the pungent note, are often related to the production process.

  • Stimulus error: occurs when the judge is influenced by irrelevant details that “suggest” differences between the products. We all know the example of a group of sommeliers who were asked to describe a