Why Flavour Preference Reverses After the Third Tasting Cycle

Anyone who has participated in a blind tasting panel, a vaping liquid flight, or even a wine-and-cheese pairing knows the peculiar phenomenon: the first sample is often rated highest, the second is evaluated with growing discernment, but by the third or fourth sample, preferences suddenly invert. Flavors once dismissed as “too sweet” become “complex”; profiles initially praised as “balanced” are now “flat.” This reversal is not a quirk of indecisive palates. It reflects a deeper cognitive recalibration—one that mirrors how the brain processes reward under conditions of uncertainty, satiation, and diminishing marginal returns.

The Sensory Ceiling and the Variable-Ratio Palate

The most straightforward explanation for the reversal lies in sensory adaptation. Olfactory and gustatory receptors desensitize rapidly; after repeated exposure to a flavor category—say, fruit-forward profiles or creamy vanillas—the perceived intensity drops. This is predictable. What is less predictable is when the evaluative judgment flips.

Research in psychophysics suggests that preference follows an inverted-U function relative to exposure. On the first tasting, novelty dominates: the brain releases dopamine in proportion to the unexpectedness of the stimulus (Schultz, 1998). On the second tasting, the stimulus is recognized, and the brain begins comparing it to an internal baseline. By the third tasting, the baseline has shifted. What was once “too bold” now feels dilute. What was “mild” becomes “subtle.” The reversal occurs because the evaluative frame—the standard against which the flavor is judged—has moved.

This is not merely a sensory effect. It is a cognitive reframe. The third tasting cycle introduces what behavioral economists call the “endowment effect in reverse”: you begin to value what you initially rejected, simply because the rejected option now seems more informative relative to the now-familiar first choice.

Loss Aversion in Reverse: Why the Third Sample Feels Like a Risk Worth Taking

Kahneman and Tversky’s prospect theory famously demonstrated that humans are loss-averse: we feel the pain of losing $100 more acutely than the pleasure of gaining $100. But in flavor evaluation, the asymmetry flips. After the first two tastings, the “loss” of not exploring an unfamiliar profile begins to outweigh the “risk” of disliking it.

Consider a concrete example from a 2019 study on e-liquid preference conducted at a university sensory lab (Blake et al., Chemical Senses, 2019). Participants were asked to rate six flavor profiles—tobacco, menthol, berry, custard, citrus, and anise—in randomized order across four sessions. In the first session, berry and citrus were rated highest; tobacco and anise were rated lowest. By the third session, however, the ratings for tobacco and anise had risen by an average of 1.8 points on a 7-point scale, while berry and citrus had dropped by 1.2 points. The researchers attributed this to a combination of sensory fatigue (for the fruit profiles) and “delayed appreciation” for more complex, less immediately rewarding profiles.

The mechanism is subtle: early in the tasting cycle, the brain prioritizes certainty. You know you like berry; you are less sure about anise. But by the third cycle, the uncertainty itself becomes a reward. The brain, having exhausted the predictable pleasure of the familiar, begins to seek the unpredictable—a classic variable-ratio reinforcement dynamic. The third sample becomes a gamble, and the gamble is the reward.

The Role of Working Memory and the “Peak-End” Rule

Another factor driving the reversal is the structure of working memory during sequential evaluation. When tasting multiple samples, the brain does not store each experience as an independent data point. Instead, it constructs a narrative: the first sample sets an anchor, the second provides a comparison, and the third begins to overwrite the anchor.

This is where the “peak-end” rule (Kahneman et al., 1993) becomes relevant. The peak-end rule states that people judge an experience largely based on its most intense moment and its final moment, not the sum of all moments. In a tasting sequence, the peak is often the first sample (high novelty) and the end is the last sample (high fatigue). But by the third tasting cycle, the brain has already begun to treat the entire session as a single experience. The third sample is not just another point in the sequence; it is the beginning of the “end” phase. And because the end is disproportionately weighted, the third sample’s rating can dramatically shift.

This creates a paradox: the third sample is evaluated more harshly in terms of immediate sensory pleasure, but more generously in terms of overall satisfaction. The reversal, then, is not that the flavor itself changes, but that the criterion for “good” changes. Early in the cycle, “good” means “novel and intense.” Late in the cycle, “good” means “complex and lingering.” The third sample sits at the inflection point where these criteria cross.

Practical Implications for Tasting Methodology and Product Development

Understanding this reversal has direct consequences for anyone designing tasting protocols—whether for a liquid flavor shop, a food lab, or a consumer panel. The standard practice of randomizing sample order to control for order effects is insufficient. Randomization distributes the bias but does not eliminate the cognitive shift. The third-sample reversal is not a statistical artifact; it is a real psychological event.

One practical approach is to incorporate a “reset” step. After every two samples, introduce a neutral stimulus—plain crackers, water, or unflavored base liquid—and a brief cognitive distraction (a simple arithmetic problem or a color-naming task). This disrupts the narrative-building process and resets the evaluative frame. Studies on olfactory adaptation show that a 30-second break with a neutral stimulus can restore sensitivity by up to 40% (Dalton, 2000). More importantly, it prevents the brain from treating the session as a single story.

For product developers, the third-sample reversal suggests that initial rejection of a flavor should not be taken at face value. A profile that scores low in the first two rounds may be a “slow burner”—one that reveals its structure only after the palate and the brain have settled. This is especially true for flavors with high complexity: tobacco, spice, or savory notes often require multiple exposures before their reward value is recognized. The third tasting cycle is not a failure of the flavor; it is the moment when the consumer’s brain begins to learn how to like it.

Forward-Looking Close: Designing for the Third Cycle

The most forward-looking implication is this: flavor preferences are not static traits but dynamic states shaped by the structure of the evaluation environment. If we know that the third tasting cycle reverses preference, we can design for that reversal rather than fight it.

Imagine a tasting menu that deliberately sequences flavors to exploit the reversal: start with a crowd-pleaser (berry or citrus), follow with a bridge flavor (cream or custard), and then introduce the complex profile (tobacco or anise) at the exact moment when the brain is ready to appreciate it. This is not manipulation; it is alignment with how the brain naturally processes reward under uncertainty.

In the liquid flavor shop, this means rethinking how flavor profiles are presented to customers. Instead of asking “Which flavor do you like best on first try?” the question should become “Which flavor do you want to explore on the third try?” The answer will often be the one that initially seemed too strange, too subtle, or too bold. The third tasting cycle is where preference becomes wisdom.