The type of glass used to drink wine can greatly affect the taste. Why go through the trouble of learning the proper way to consume wine if you don't serve it in the right glass? Once you learn the basic parts of a wine glass, and what purpose they serve, you can select the right glass for the right wine and maximize your wine tasting experience.
The lip of the wine glass is simply the top rim. The lip helps to concentrate the aroma when sniffing. The degree to which the lip or rim is tapered from the bowl affects where the wine is directed to in the mouth. The lip of white wine glasses is narrow, like the bowl, to direct the wine better to the front of the mouth. The lip of red wine glasses is wider, as the aroma is less delicate, and directs the wine to the back and sides of the tongue.
The bowl is the part of the glass that actually holds the wine. In general, all wine glasses should have a bowl that is wider at the bottom and narrower at the top, to concentrate the aroma. Also, the bowl should be clear, smooth and not have anything that interferes with swirling the wine. Red wine benefits from a shorter, wider bowl, while white wine is more traditionally served in a taller, more narrow bowl—think balloon versus tulip.
The stem supports the bowl above and attaches it to the foot or base below. It also keeps the warmth of your hands away from the bowl, where it could affect the temperature and flavor of the wine itself. The stem should be sturdy and tall enough to comfortably hold but not so tall as encourage breakage or tipping. It should also be firmly attached at the bowl and base.
The foot or base of the glass serves the basic purpose of keeping it upright by providing a flat surface. It should be firmly attached to the stem and strong enough to avoid snapping if held instead of the stem for swirling when tasting. The base should also be broad enough to support the glass, at least when filled to the halfway point. While the base is a critical part of the glass structure, it does not affect the taste of the wine.