that we cannot be as analytical as for taste—we can discriminate and taste sweet, sour, and salty for example, but smell has the property of being “synthetic” according to Shepherd4—a mixture of smells makes a unified smell. So, we need to think further about this. Hopefully, the reader will start to think more carefully about individual flavor notes and the whole flavor profile of each product in their portfolio. How is that overall profile synthesized or built up in the brain from the selective detections of its individual components? It is very easy to detect both sour and salt in a mix but defining a mix of even just a few different smells is incredibly complex. In-fact it is suggested that we cannot do this for more than 3 or 4 different flavor compounds in a mix.1, 3, 4 So much for looking at dozens or hundreds of molecules in our whiskey, rum or gin and becoming an “expert?” But see below.
Other mouth-senses and flavor In addition to smell and taste, foods and drinks possess physical properties that can be evaluated by the mouth—we call this mouth-feel, mouth-sense or food/liquid texture (viscosity). These sensations involve touch, pressure, temperature and pain (the burn of alcohol or chili pepper or the cooling effect noted with menthol, etc.) and are detected by a system called the trigeminal nerve pathway. Along with visual and auditory signal processing, the evaluation of our spirits and foods is quite involved. We will not delve further into the qualities of mouth-sense, touch, feel and texture here—nor the visual and auditory aspects of flavor evaluation—but the two books written by Shepherd and those by Holmes, Gilbert and Spence convey the details comprehensively and admirably.1-5 For now, just be aware of these other senses and the roles they play. It should be pointed out though that increasing heat releases more volatile compounds and stimulates olfactory receptors more strongly by retronasal smell, and illustrates the reason for not assessing products too cold. In terms of pain and sensory fatigue (a topic covered in sensory evaluation training) it is often best to reduce spirits from 40% ABV or above to about 20% ABV as routinely done in the Scotch whisky industry to better assess samples. Especially important for side-by-side comparison of two or more products. Though both full strength and diluted spirits could be assessed to try and get at all the flavor nuances. Be sure not to be deceived by the color differences though in diluted and undiluted samples! In routine training an instructor will often have the student or panelist assess the product at strength and then suggest adding a drop or two of pure distilled water to “open up the spirit” for further assessment of the volatiles. A discussion of ethanol-water composition and the effects on volatile release, determination and sensory evaluation appears elsewhere.12, 13 A summary note here would be that the flavors of our distilled spirits are enhanced by heating and dissolving in water (liquid). This increases the vapor pressure which causes volatile molecules to be released into the air from the glass or within the mouth. Moreover, volatile molecules released from our food and drinks are so very important to our
survival that they are evaluated quickly at the highest structures of the human brain.4 We quickly learn that which is bad for us! And sometimes even aromatically “bad” molecules contribute to the overall quality and acceptance of a product. Do you see some potential for bias here? Paraphrasing Shepherd4 here, for a very important point about assessing distilled spirits, “All spirit descriptive language is in fact organized around spirit types which we call prototypes. If this is in fact correct, what a spirits taster does in front of a spirit is not an analysis of its separate sensory properties but a comparison of all the cognitive associations he or she has from the spirit (color, initial aroma, and taste) with the impressions he or she has already experienced when tasting other spirits.” The aroma sense is synthetic as noted above. Shepherd was dealing with wine—we assume the same works for spirits. A take home message here. What Shepherd and others tell us is that descriptive language becomes important to our abilities to describe and distinguish between similar products. We train on known samples which may be spiked or enhanced with a specific, purified flavor note. We learn to assign that flavor a descriptive term or terms and learn about its origins in the production process, so we can detect its presence in future samples. See below for more on language and flavor profiling.
Let’s chew on some other flavor assessment ideas While we now understand that all our senses come in to play in our assessment of our distilled spirits we do not often think about chewing our food—or drink for that matter—to better assess their overall qualities. Yet chewing upon or swishing a drink in our mouths brings it into contact with all corners and orifices of the oral cavity—cheeks and throat—and adds to that retronasal assessment. Dilution with our saliva, and digestion from salivary enzymes affects the qualities and release of aromatic components as does, if it can be done, sucking in a little air while holding liquid in the mouth. Those “sucking” and “ooshh” sounds emanating from experienced wine tasters are not mere snobbish entertainment or to incite amusement from fellow diners. Make more use of your tongues and mouth muscles! A short chapter by Shepherd mulls this over even more.4
X is different from Y and this tastes like a ripe banana, not a green one So, all our sensory modalities—our ways of doing or experiencing something are being extensively researched today. Vision (color) and somatosensory (tactile sensations: including pain, temperature, astringency, and creaminess), and taste (sweet, umami, salt, sour and bitter), and smell (through the generation of smell images) allow us to recognize a flavor. Even nuances of flavor: unripe, green, ripe, yellow, old-browning or over-ripe and mushy, slimy or rotten banana. Moreover, this allows us to state that sample x is different
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