A wine glass is a type of glass stemware which is used to drink and taste wine. It is generally composed of three parts: the bowl, stem, and foot. Selection of a particular wine glass for a wine style is important, as the glass shape can influence its perception.
Proper Use
It is important to note the most obvious, but often most neglected, part of the wine glass—the stem. The proper way to drink from the wine glass is to grasp it by the stem and drink. The purpose of this is so the temperature of the wine is not affected when holding the glass. This is achieved because the stem is not in direct contact with the wine. It would be more difficult to control the temperature of the wine if one held the glass by the bowl because it is in direct contact with the wine.
Materials
Wine glasses made of fused or cut glass will often interfere with the flavor of the wine, as well as creating a rough, thick lip, from which it is not as pleasurable to drink. Blown glass results in a better vessel, with a thinner lip, and is usually acceptable for casual wine drinkers. High quality wine glasses are often made of lead crystal, which is not technically crystal, but is merely called it through convention.[citation needed] Lead crystal glasses’ advantages are primarily aesthetic, having a higher index of refraction, thus changing the effect of light passing through them, but lead poisoning becomes a danger. Using lead in the crystal matrix also offers several advantages in the material’s workability during production. Wine glasses are generally not coloured or frosted as this would impede the appreciation of its colour.
Shapes
The shape of the glass is also very important, as it concentrates the flavor and aroma (or bouquet) to emphasize the varietal’s characteristic. The shape of the glass also directs the wine itself into the best area of the mouth from the varietal. Though to say that a given varietal has a specific target area of delivery in the mouth is wildly speculative, despite the marketing attempts of prominent stemware manufacturers, such as Riedel and Spiegelau, to make consumers believe this. Some small benefit may be derived from drinking a given varietal from its specially designed glass, but to go so far as to say it improves the taste of the wine would be to go too far. In general the opening of the glass is not wider than the widest part of the bowl.
The stem of a glass is an important feature as it provides a way to hold the glass without warming the wine from body heat. It also prevents fingerprints from smearing the glass, and makes the glass easier to swirl. Except for the wine connoisseur, wine glasses can be divided into three types: red wine glasses, white wine glasses and champagne flutes.
White wine glasses
White wine glasses are generally narrower, although not as narrow as champagne flutes, with somewhat straight or tulip-shaped sides. The narrowness of the white wine glass allows the chilled wine to retain its temperature for two reasons;
The reduced surface area of the glass (in comparison to red wine glasses) means less air circulating around the glass and warming the wine.
The smaller bowl of the glass means less contact between the hand and the glass, and so body heat does not transfer as easily to the wine.
Decoration
In the 18th Century, glassmakers would draw spiral patterns in the stem as they made the glass. If they used air bubbles it was called an airtwist if they used threads, either white or colored, it would be called opaque twist. [1]
ISO Wine tasting glass
The ISO has standardized a series of glasses for wine tasting. They are stemmed with elongated, tapered bowls, with capacities of 120 (for sherry), 210, 300 or 410: milliliters.ISO 3591:1977
Source: http://en.wikipedia.org/wiki/Wine_glass
