The wine glass is the final tool used (besides the human senses) in wine consumption and appreciation. Of course, the most important factor is that the glass must be clean so as to serve as an inert recipient for the wine. Any good glass or crystal stemware will serve the purpose just fine. However, a glass which has been constructed with special care for a specific wine or grape variety can further elevate the wine tasting experience. Though a poor or faulty wine cannot be masked with a high quality glass, a good or great wine can be accentuated, highlighted, with its finest character traits emphasized by drinking it from a superior glass.
It is now common to find basic "red" and "white" wine glasses. Typically the red wine glasses have a much more voluptuous bowl allowing for greater air to wine surface area, bringing out the red wine's characteristics. White wine glasses tend to be slimmer with less of a bulging bowl. Mirroring the custom with food serving sizes, American glassware is much larger than typical European glassware.
Some specialty glassmakers, like the eponymous Riedel family, have created an elite reputation based on their varietal glasses and different glass "series". It was discovered that the shape and potential volume of a glass, the radius of its rim, and the thickness of the crystal are all key factors determining how the wine's aroma reaches the nose and where the wine flows over the various taste zones of the tongue. The first varietal glass Riedel made was designed for Burgundy Grand Cru, (Pinot Noir), and is now on display in the NYC Museum of Modern Art. Riedel and other manufacturers make glasses to accentuate the following wines, just to name a few: Chablis/Chardonnay, Sauvignon Blanc, Riesling, Loire, Alsace, Sauternes, Rheingau, Burgundy Grand Cru (Pinot Noir), Cabernet Sauvignon/Merlot, Tinto Riserva, Chianti Classico/Zinfandel, Hermitage.
Why so many different styles of glasses? According to Riedel, "Better wine is being produced today by more people in more places than ever before in history, with world-class wine being made by literally thousands of wine-makers. Wine enthusiasts go to great lengths to discover these wines, buy them in sound condition, store them properly, serve them at the correct temperature and in surroundings that enhance them. Shouldn't they also drink them from glasses that bring out their maximum beauty? Is a glass's impact on the taste of wine fact or fiction? In his highly regarded wine journal, Robert M. Parker Jr. of The Wine Advocate, says, "The effect of these (specially designed) glasses is profound. I cannot emphasize enough what a difference they make." Experiment with the same wine served in different types of glassware and decide for yourself.