A wheat beer glass is a glass that is used to serve wheat beer, known also as Weizenbier or Weißbier. The German glass generally holds 0.5 litres with room for foam or "head". It is much taller than a pint glass, and is considerably wider at the top than at the base, with a slight hourglass taper toward the bottom. This design purportedly allows greater production of foam, as well as increased exposure to air when the glass is tilted back. In other countries such as Belgium, the glass may be 0.25 litres or 0.33 litres.
Because of its unique shape, extra care must be taken when pouring a beer into a wheat beer glass to produce the desired head volume. The traditional method of pouring Weißbier is to first rinse the glass with cold water, then, without drying the glass, hold the bottle and glass almost horizontally while slowly pouring the beer. When the level of the beer touches the lip of the bottle, slowly bring the glass upright. When there is less than one inch (or a few centimeters) of beer left in the bottle, swirl the bottle vigorously to pick up the sediment and create foam, which is poured on top. If done correctly, the foam should just crest the lip of the glass without pouring over. (Full article...)