The Landscape of Taste: Flavors and Scenery.
The Landscape of Taste
"The most delicious coffee is different for everyone."
This time, we will explore what taste differences are, how much they influence individual preferences and coffee preferences, and the perspectives that emerge from these considerations.
"Taste Differences" Everyone Experiences
For example, when eating the same meal with a friend, one might say "delicious" while the other says "I'm not so keen on it." Everyone must have had such an experience.
Cilantro is a typical example. For some, it has a refreshing aroma, while for others, it tastes like "soap."
This is explained by differences in the olfactory receptor gene (OR6A2), which causes variations in how people perceive aroma components (aldehydes).
Similarly, the bitterness of bitter gourd and the hoppy notes of beer can also be perceived very differently by different people. Scientifically, the perception of bitterness can be measured by an experiment called the "PROP test," which is known to categorize individuals as follows:
• Supertasters (about 25%): Perceive intense bitterness.
• Medium Tasters (about 50%): Perceive moderate bitterness.
• Non-tasters (about 25%): Perceive almost no bitterness.
In other words, even with the same food or drink, a "completely different world of taste" can unfold due to genetic factors.
Scientific Background of Taste
Research indicates that taste differences are broadly caused by the following factors:
1. Genetic Factors
Example: Variations in the bitter taste receptor gene (TAS2R38) can alter bitterness sensitivity by several to tens of times.
2. Anatomical Factors of the Tongue
People with a higher number or density of "fungiform papillae" on the front of the tongue tend to perceive tastes more intensely.
3. Age and Gender Differences
Generally, children are more sensitive to taste than adults. Sensitivity is said to decrease with age, and some studies also show that women tend to have higher taste sensitivity.
4. Lifestyle and Environment
Smoking dulls bitterness sensitivity. Habits of consuming high salt or sugar can alter taste perception standards.
5. Psychological and Physiological State
Taste can also fluctuate due to stress and hormonal balance.
How Significant are the Differences? (Quantitative Examples)
Research data shows that these differences are much greater than imagined.
• Detection Threshold
A concentration difference of "120 to 1,000 times" for the same taste substance has been reported. For some, a minute amount is enough to taste, while for others, it requires 100 times the concentration to be perceptible.
• Just Noticeable Difference (JND)
For food examples, reports indicate that consumers can detect a difference when the sweetness of cola is reduced by about 9%. This means that with a 10% adjustment, some people will notice a "change in taste."
• PROP/PTC Experiment (Bitterness Sensitivity)
It is also reported that supertasters perceive bitterness more than 10 times stronger than non-tasters.
Individual Differences in Taste for Coffee
Applying this knowledge to coffee:
• While some people find light-roasted coffee to be "fruity and sweet," others say it's "just sour."
• Some enjoy dark-roasted coffee as "powerful," while others dislike it as "burnt-smelling."
These differences can be said to be "more about how sensations are perceived than a matter of preference."
Professional tasters (such as Q Graders) can distinguish tastes and aromas more finely through training, etc. However, this is thought to be due to an increase in the brain's resolution (details on resolution will be discussed later), rather than a significant change in taste perception itself.
Summary so far:
• Taste varies significantly depending on genetics, experience, and environment.
• Sensitivity to bitterness and sweetness differs by several to tens of times among individuals.
• At an everyday level, some people notice a 9% change in taste.
• Differences in coffee evaluation among people are inevitable, and this demonstrates human diversity.
Let's consider this further.
What Changes with Continuous Coffee Consumption
In conclusion, it is believed that continuously consuming beverages like coffee, which have a complex interplay of bitterness, acidity, and aroma, can lead to changes in taste "sensitivity" and "resolution." However, these changes have several aspects and can be scientifically categorized into "changes in physiological thresholds" and "changes in cognition and learning through experience."
1. Changes in Physiological Taste Sensitivity
• Potential for the threshold itself to change:
There are reports that high-salt diets increase the salt taste threshold (meaning it becomes harder to perceive saltiness unless it's more concentrated), and high-sugar diets increase the sweetness threshold. Similarly, frequent coffee drinkers are suggested to have an increased detection threshold for bitterness and acidity (meaning they become less sensitive).
→ Dullness due to physiological "habituation."
• Sensory adaptation:
Repeated intake of bitterness and acidity can lead to a state where the "taste feels weaker" both momentarily and continuously.It is believed that this significantly influences why daily coffee drinkers do not perceive "bitterness as intensely" as others.
2. Cognitive and Learning Changes (Improvement in Resolution)
• Improvement in flavor discrimination ability:
Studies on wine and coffee taster training have confirmed that repeated learning leads to an improvement in "the ability to distinguish and verbalize differences," even if "thresholds remain largely unchanged."
→ This aspect can be called "an increase in resolution."
For example, what was once perceived as "just bitter" can, with continuous drinking, be differentiated and expressed as "grapefruit-like bitterness" or "cacao-like bitterness."
• Differences due to focused attention:
When one intentionally focuses on specific elements of taste or aroma during training, they become more sensitive to those elements. This is believed to be a result of changes in the brain's resource allocation for sensory processing.
3. Coffee-Specific Elements
• Since coffee involves the simultaneous action of bitterness, acidity, sweetness, umami, astringency (polyphenols), and aroma components, continuous consumption allows one to learn "which part of the mixed taste to focus on."
• Regarding "acidity" in particular, beginners often perceive it as "sour = unpleasant," but reports indicate a tendency for experienced drinkers to positively evaluate it as "bright acidity" or "fruitiness."
To summarize the above:
• Thresholds (physiological sensitivity) can increase (become dull) with repeated consumption.
• However, "resolution (the ability to distinguish subtle differences)" significantly improves with experience and training.
• When drinking coffee continuously, a dual change can occur: one becomes "less sensitive to the intensity of bitterness and acidity" while becoming "more sensitive to differences in flavor and quality."
Even when drinking the exact same coffee, the world perceived by each person is unique.
As stated above, the perception and interpretation of complex coffee flavors vary among individuals, so it should be impossible to evaluate individual taste differences beyond a defined set of specific evaluation criteria.
Even baristas, roasters, and tasters, who drink "good coffee" more than anyone else, have their own preferences for coffee.
With this premise, by discussing "differences in perception" while drinking the same coffee with someone, or by seeking the "most delicious coffee" that only you can savor, and enjoying these very differences, new perspectives will surely open up through coffee.
As someone who delivers coffee, I always strive to provide special coffee with excellent flavor and quality, and many stories that cannot be perceived by taste alone. However, no matter what kind of coffee it is, it goes without saying that you are the one who ultimately determines its value, for better or worse.
Without being constrained by anything, enjoy various coffees in diverse ways. From there, new horizons might open up.
Representative papers, references, and sources
1. Nutrition Reviews (Temporal patterns…) — A review article demonstrating large individual differences (120-1,000×).
2. “Just noticeable difference in sweetness perception of cola” — An example of measured JND in food (approx. 9%).
3. PMC: Association between Genetic Variation in the TAS2R38 … — Relationship between TAS2R38 and PROP sensitivity (genetic explanation).
4. The Taste Detection Threshold (TDT) Test — Procedures and explanation of threshold measurement methods.
5. “The Relationships Between Common Measurements of Taste Function” — Comparison and relationship of measurement methods such as thresholds, suprathreshold evaluation, PROP, and papillae count.