The results of the four recognized stages to wine tasting –

• appearance
• "in glass" fragrance
• "in mouth" sensations
• "finish" (aftertaste)

– are combined in order to establish the following properties of a wine: complexity and character

• potential (suitability for aging or drinking)
• possible faults

A wine's overall quality assessment, based on this examination, follows further careful description and comparison with recognized standards, both with respect to other wines in its price range and according to known factors pertaining to the region or vintage; if it is typical of the region or diverges in style; if it uses certain wine-making techniques, such as barrel fermentation or malolactic fermentation, or any other remarkable or unusual characteristics.

Whereas wines are regularly tasted in isolation, a wine's quality assessment is more objective when performed alongside several other wines, in what are known as tasting "flights". Wines may be deliberately selected for their vintage ("horizontal" tasting) or proceed from a single winery ("vertical" tasting), to better compare vineyard and vintages, respectively. Alternatively, in order to promote an unbiased analysis, bottles and even glasses may be disguised in a "blind" tasting, to rule out any prejudicial awareness of either vintage or winery.

Blind tasting

To ensure impartial judgment of a wine, it should be served blind — that is, without the taster(s) having seen the label or bottle shape. Blind tasting may also involve serving the wine from a black wine glass to mask the color of the wine. A taster's judgment can be prejudiced by knowing details of a wine, such as geographic origin, price, reputation, color, or other considerations.

Scientific research has long demonstrated the power of suggestion in perception as well as the strong effects of expectancies. For example, people expect more expensive wine to have more desirable characteristics than less expensive wine. When given wine that they are falsely told is expensive they virtually always report it as tasting better than the very same wine when they are told that it is inexpensive. French researcher Frédéric Brochet "submitted a mid-range Bordeaux in two different bottles, one labeled as a cheap table wine, the other bearing a grand cru etiquette" and obtained predictable results. Tasters described the supposed grand cru as "woody, complex, and round" and the supposed cheap wine as "short, light, and faulty." Blind tastings have repeatedly demonstrated that price is not highly correlated with the evaluations made by most people who taste wine.Fact: date=November 2007 On the other hand, some extremely expensive wines of great fame, such as Chateau Petrus and Domaine de la Romanée-Conti, consistently receive the highest ratings in blind tastings of professional reviewers such as Robert Parker.