What can we learn from these tests? First, that tasting wine is really hard, even for experts. Because the sensory differences between different bottles of rotten grape juice are so slight—and the differences get even more muddled after a few sips—there is often wide disagreement about which wines are best. For instance, both the winning red and white wines in the Princeton tasting were ranked by at least one of the judges as the worst.The perceptual ambiguity of wine helps explain why contextual influences—say, the look of a label, or the price tag on the bottle—can profoundly influence expert judgment.
Jonah Lehrer confirms what we all suspected: when it comes to wine, most people are just guessing.