Anatomy & Physiology of Flavor

You walk into a bar and spy your favorite beer brand on tap.  Your mouth begins to water and a smile creases your lips.  There is a lot going on in your head and you've not even ordered yet!!

Beer drinking is such a sensual experience – you already knew that! But why?

At the most basic level of beer sensation ~     FLAVOR = SMELL + TASTE

But there is more to it than that -

Beer Sensory Experience = Flavor + Other Sensory Perception (visual, temperature, texture (mouth feel), pain) + memory + emotional state!!

To better explain:

The sensual experience of drinking beer depends upon a complex, multifunctional and interactive sensory system that allows you to perceive and categorize the unique chemical and sensory signatures that each brew brings to the table.

The first thing any craft beer lover does is take a long, deep whiff of that beautiful beer aroma. Taking in smell molecules (odorants) through the external portion of the nose (external nares) is referred to as the orthonasal route of smell (olfaction). When you take the beer into your mouth the volatile odorants in the beer can also travel into the nose by passing under and then behind the soft palate into the internal portion of the nose (internal nares). This is referred to as the retronasal route of smell (olfaction). Whether by the ortho or retro nasal routes the unique volatile and aerosolized odorants in the beer are detected by the smell (olfactory) receptors in the roof of the nose. This information is then transmitted via the olfactory nerves to the olfactory bulb and then via the olfactory tracts to the primitive olfactory cortex in the brain. At the same time, information about the smell is similarly transmitted to higher brain centers involved in conscious perception, analysis, categorization, memory and emotional response.  

Smell sensation takes two paths to the brain

Smell sensation takes two paths to the brain

The next thing you do, after enjoying the beer’s aroma is the best part – Drinking in that delicious smooth liquid ~

Taste (gustatory) receptors on the tongue, palate, and pharynx (throat) detect the salt, sweet, sour, bitter and umami (soy sauce-like) signatures of taste molecules (tastants). As beer passes over the tongue, these receptors send taste information to the brainstem relay station (nucleus of the tractus solitaries) via electrical roadways – or nerves.  The seventh (7th or facial), ninth (9th or glossopharyngeal) and tenth (10th or vagus) nerves are the roadways that lead to the brainstem.  

Taste traveling to the brain

This information is then transmitted to brain’s primary relay station, the thalamus, before it is eventually relayed to even higher centers in the brain centers.  These higher brain levels are responsible for conscious perception, analysis, categorization, memory and our emotional responses. 

Meanwhile, superimposed upon the gustatory and olfactory experience, beer drinking also includes the perception of temperature (warm, cold), mouth feel (thin, thick) and potentially pain perception - for those brews that include capsicum containing chili peppers. That’s right – “hot” is not a taste sensation it is a PAIN sensation!!

This information is relayed via the fifth (5th or trigeminal) cranial nerve roadway and then directed to the thalamus where it is processed and sent to even higher brain centers for storage as a memory and emotion.

The central nervous system plays an important role in determining what type of beer you and your friends like to savor.  Integration of gustatory, olfactory, touch, temperature and pain sensation underlies your sensual experience of beer while the central nervous system regions involved in memory and emotional response further enrich your experience.

So try something different next time you order a craft beer and make some great memories!!

Got it?  Let me know if you have questions!