White wine glasses
A smaller bowl and mouth helps to lock in the aromas of the wine, and keep the chilled contents colder for longer. When drinking white wine, the glass should be held by the stem to avoid the heat of your hand raising the wine's temperature.
Red wine glasses
A generous bowl size and wider mouth allows the wine to breathe and flavours develop (a process called oxidisation). The glass should only be filled to widest point of the bowl, to give the wine plenty of room to breathe so the flavour and aroma can develop at a faster rate.
The long, elegant bowl of the flute is designed to maximise bubbles and sparkle. Generally used for sparkling wines such as Champagne, Cava and Prosecco, which are served cold, champagne flutes should be held by the stem to prevent hand temperature from warming the contents.