Walk into a tasting room anywhere from the Willamette Valley to the Finger Lakes and the pours arrive in the same broad order. The sequence is built around the limits of the palate rather than around the lineup.
What palate fatigue actually is
Repeated exposure dulls the response to a flavor. Tannin, sweetness and alcohol all accumulate on the palate and shift how the next sample registers.
The effect is asymmetric. A heavy sample distorts a light one that follows far more than a light sample distorts a heavy one.
Ordering the flight is therefore a way of protecting the samples that are most easily overwhelmed, by placing them where nothing is standing in front of them.
Why the sequence runs light to heavy
Sparkling wines usually open a flight because their acidity and carbonation leave the palate cleaner than they found it.
Dry whites follow, then rosés, then reds in ascending order of tannin and body, with anything oaked placed after its unoaked counterpart.
Sweet wines come last because residual sugar lingers and makes anything dry that follows read as thin and sour by comparison.
How alcohol changes the sequence
Higher-alcohol wines contribute a warming sensation that persists, so a flight ordered strictly by weight can still mislead if a strong sample sits early.
Fortified wines are separated deliberately for the same reason, often served at the end or in a distinct flight of their own.
Spirits tastings apply the same principle more sharply, since ethanol dulls the palate quickly and a heavily peated or cask-strength sample ends the useful session.
Why the room controls the conditions too
Tasting rooms limit strong aromas in the space, because perfume, smoke or food nearby competes directly with what is in the glass.
Neutral crackers and water are provided to reset between pours, and spit buckets exist so that the sequence can be completed with judgment intact.
Lighting and glass shape are controlled as well, since color assessment and aroma concentration both depend on conditions the room can standardize.
What the order implies about the verdict
Because sequence affects perception, a wine's position in a flight influences the impression it makes, and experienced tasters account for that when comparing notes.
Formal judging deals with the problem by randomizing order across panels and by re-pouring outliers separately.
A tasting room is not a judging panel. Its sequence is designed to show each wine well, which is a different objective and worth remembering when reading one's own notes afterward.