They did not drink the same liquid
The first explanation to eliminate, and the one most often skipped. Two people tasting a tea at different times, from different pots, with different water, at different ratios or at different temperatures are not disagreeing about a tea — they are describing two preparations. Water is the largest and least suspected variable: mineral content varies enormously between supplies, hard water flattens aromatics and adds a drying grip, and very soft water gives a hollow liquor. Temperature at the moment of tasting changes what is reported, with bitterness generally reading as less prominent as a cup cools and sweetness as more, which is why professional evaluation standardises it. Infusion number changes everything, since the fast sweet aromatic fraction leaves early and the astringent fraction keeps arriving. Even the vessel matters, because a narrow cup concentrates the air above the liquid and directs it towards the nose while a wide bowl disperses it. Any comparison worth having therefore holds all of this constant and brews simultaneously rather than in sequence, and any disagreement conducted without doing so is unresolvable in principle.
They do not detect the same compounds
Individual differences in olfactory sensitivity are real, well documented for several classes of odorant, and large. Some people detect a given compound at a small fraction of the level another person needs, and for certain compounds a proportion of the population detects essentially nothing at all — a specific insensitivity rather than a general one, so the same person may be unusually sensitive to something else. Detection thresholds also differ between compounds by orders of magnitude, which means a compound present in a vanishing quantity can dominate a profile for one taster and be absent for another. This is not a matter of training or attention and it cannot be corrected by either. It is the strongest single argument for weighting notes that recur across many independent descriptions and holding single vivid ones lightly, and it is one of the reasons this catalogue keeps a coarse controlled vocabulary alongside its prose. It is also a reason for courtesy in a tasting: a taster who cannot find what somebody else is describing may be entirely right about their own experience.
They have different reference sets
Every note is a comparison to something the taster is assumed to know, and the assumption fails constantly across cultures and households. Sweet potato as a note for Dian Hong works for a taster whose reference is the Chinese variety and works poorly otherwise. Longan, osmanthus, yam, jujube and cassia bark all assume familiarity, and in the other direction blackcurrant, digestive biscuit and malt loaf assume a British reference set that travels badly. Two tasters can therefore be detecting exactly the same thing and reaching for different names, which looks like disagreement and is a translation problem. The diagnostic is to ask what the other person means rather than whether they are right: a taster who says a tea is fruity and one who says it is like dried longan may be in complete agreement, and one of them has a narrower reference available. This is also why a tasting note is best read as a pointer to a resemblance rather than as a claim about the liquid, which is the position the whole of this catalogue takes.
They are attending to different dimensions
A cup delivers taste, aroma, mouthfeel and a sequence over time, and tasters weight them differently by habit and by training. Somebody whose attention sits on aroma will describe a tea by its top notes; somebody who attends to texture will describe the same cup by its body and its grip and may barely mention what it smells of; somebody trained in a tradition that values the finish will report almost entirely on what happened after swallowing. None of them is wrong and their descriptions may not overlap at all. The remedy is structural rather than perceptual: a shared framework — taste, aroma, mouthfeel, finish, and the change across infusions — makes it clear when two people are describing different dimensions rather than contradicting one another. Professional cupping does exactly this by scoring brightness, briskness, colour and body separately rather than producing a single verdict, and the discipline is worth borrowing informally. Most tasting disagreements dissolve the moment both people are asked which dimension they are talking about.
Expectation is doing more work than anyone admits
Price, packaging, provenance, the seller’s description and the opinion of whoever spoke first all move sensory judgement, and they move it for everybody including people who believe themselves immune. A note read before tasting is very likely to be found; a tea known to be expensive is rated more highly; and sensory judgements converge rapidly once spoken aloud in a group, which is pleasant socially and destroys the independence of every observation after the first. These are well-established effects in sensory evaluation generally rather than a failing of tea drinkers in particular. The practical responses are simple and are worth applying whenever a comparison matters: write before speaking, taste before reading the description, and where the question is genuinely important, taste blind. A blind comparison between an expensive tea and a modest one from the same category is the single most instructive exercise in this catalogue, and its results are frequently uncomfortable for exactly the reasons this paragraph describes.
The palate itself is not constant
The same taster disagrees with themselves. Astringency accumulates across sips and across cups, so the third cup of a black tea from the same pot is harsher than the first without the liquor having changed; a delicate tea tasted after an assertive one reads as thin when it is not; and recovery between sessions takes longer than most people allow. Time of day, what was eaten beforehand, a cold, ambient temperature and simple fatigue all move what is reported, and a cold in particular removes most of what is called flavour by closing the retronasal channel while leaving the tongue working normally. These are reasons to run comparisons under consistent conditions, to taste from delicate to assertive with plain water between, to stop before the differences stop being obvious rather than when the cups are empty, and to re-taste teas already judged. A tea dismissed early is often reassessed once there is a frame for it, and a note you disagree with a year later is the clearest evidence available that your palate has moved rather than that you were careless.