Try It, You'll Like It: The Influence of Expectation, Consumption, and Revelation on Preferences for Beer
Coauthor(s): Shane Frederick, Dan Ariely.
Patrons of a pub evaluated regular beer and "MIT brew" (the same regular beer with some balsamic vinegar) in one of three conditions. One group tasted them blind (the secret ingredient was never disclosed). A second group was informed of the contents before tasting. A third group learned of the secret ingredient immediately after tasting, but prior to indicating their preference. Not surprisingly, preference for the MIT brew was higher in the blind condition than either of the two disclosure conditions. However, the timing of the information mattered substantially. Disclosure of the secret ingredient significantly reduced preference only in the before condition, when it preceded tasting, suggesting that disclosure affected preferences by influencing the experience itself, rather than by acting as an independent negative input or by modifying one's retrospective interpretation of the experience.
Source: Psychological Science
Lee, Leonard, Shane Frederick, and Dan Ariely. "Try It, You'll Like It: The Influence of Expectation, Consumption, and Revelation on Preferences for Beer." Psychological Science 17, no. 12 (2006): 1054-58.