When you decant a wine or port, you pour it directly from the bottle into a glass container, usually a decanter. There are several reasons for decanting a wine: to separate the bitter sediment (or bits of broken cork) from the wine, to allow the wine to breathe, and to impress your friends. The process of decanting is quite simple, but first you need to know if the wine needs decanting (most whites and many reds do not), and if it does, for how long (fragile, elderly reds can be ruined in minutes). Prior to decanting, the bottle must be left upright for at least a day to allow the sediment to settle. When it's time to decant, pour the wine smoothly and steadily— to avoid stirring up the sediment—while using a candle or flashlight to illuminate the bottle from the bottom (so you can see the sediment clearly through the dark glass). See also aeration and lees.