Sensory Exercise: Jelly Bean Test
The jelly bean test is a quick, simple sensory exercise that demonstrates the difference between orthonasal and retronasal olfaction. It is also a great way to demonstrate the difference between our sense of taste and our sense of smell.
Humans have two distinct pathways for perceiving aromas: orthonasal and retronasal. Orthonasal olfaction (olfaction is the fancy word for smelling) occurs when you smell an aroma that is outside your body, such as holding a flower to your nose or smelling petrichor. The aroma molecules travel up your nostrils and through your nasal cavity to your olfactory epithelium, which is the part of your body that is responsible for detecting aromas.
Retronasal olfaction occurs when you ingest something, and the aromas travel up your oral cavity to the olfactory epithelium. Most of the time, when people talk about how something “tastes,” they’re often talking about how something smells. Retronasal olfaction is the main component of flavor perception, not our sense of taste, although our sense of taste is also important. We experience the aroma of whatever we put in our mouths retronasally.
While orthonasal and retronasal olfaction travel through different cavities to reach the olfactory epithelium, there is no difference in the way we perceive the aromas arising from them. That is, orthonasal olfaction does not use separate receptors or signals from retronasal olfaction. What changes our perception of aroma differences is the environment in our mouth. When you take a sip of beer, the humid and moist environment of your mouth will warm up the sample, which will release more aroma molecules. The pH of your saliva will also affect your perception by increasing the pH of the beer, which makes some aromas more detectable and other aromas less detectable. Also, taste and mouthfeel will influence your retronasal perceptions.
The jelly bean exercise is also a good way to demonstrate the difference between our senses of taste and smell. One of the examples I like to use when explaining the difference between taste and smell is when we are stuffed up and say that we can’t “taste” anything. In reality, our sense of smell is what is being affected by the blocked sinuses, not usually our sense of taste. Our sense of taste has five basic tastes: sweet, sour, salty, bitter, and umami; our sense of smell can detect upwards of trillions of different aromas. Performing the jelly bean test is essentially simulating having a stuffy nose.
Sensory Exercise: Jelly Bean Test
The jelly bean test is designed to demonstrate the difference between orthonasal and retronasal olfaction, as well as the difference between our sense of taste and our sense of smell. Understanding how orthonasal and retronasal olfaction are different is a foundational key to becoming a better beer taster. It is simple to prepare and demonstrate. It is quick but highly effective.
MATERIALS NEEDED:
Jelly beans (see notes below)
Optional: individual baggies
Optional: nose plugs
PROCESS:
Divide out 4-5 jelly beans per participant.
If using baggies for participants, put the jelly beans in the baggies.
If using nose plugs, place them in the baggies as well.
EXERCISE:
Each participant receives 4-5 jelly beans or one baggie, if using.
Instruct each participant to hold their nostrils shut or put on their nose plugs. There should not be any air moving from their mouths to their nasal cavities.
Instruct each participant to place a jelly bean in their mouth, with nostrils still closed, and chew for a few seconds. Participants should note what they taste (sweet, sour, salty, bitter, umami) as well as note the absence of aroma or “flavor.”
Instruct each participant to release their nostrils and exhale through their nose, noting what aromas they perceive.
NOTES:
You do not necessarily have to use jelly beans - candy is the most common, but you can use any type of food. The jelly beans aren’t the important part - they’re just a convenient, inexpensive vehicle.
There are a variety of ways you can select the jelly beans. They can all be one flavor, they can be several flavors, and/or they can be different flavors but similar colors. What has worked the best for me is to either have two flavors with similar colors (e.g., cherry and cinnamon) or organize the jelly beans by color family, such as putting blues in one bag, yellows in another, etc.
It’s tempting to use jelly beans like Jelly Belly’s BeanBoozled jelly beans. I know it’s tempting because I attempted to use them in a presentation. Luckily, I tasted the jelly beans ahead of time and discovered that the disgusting flavors (liver and onions, barf, dead fish) were truly horrifyingly disgusting. Like gag-inducing, regret-burping nauseating. If everyone participating gives informed consent, then go bananas. Don’t surprise anyone with BeanBoozled jelly beans unless you enjoy no one ever trusting you again and being hated while having to clean up vomit.