Decanting wine is basically a process of pouring the contents of a bottled wine into a decanter vessel or another clean container. Why do we need to decant wine? Decanting wine serves two purposes: to separate clear wine from the sediment that have accumulated for years and to aerate wine with the hope to retain its aroma and flavors upon serving. Exposing wine to oxygen is beneficial to enhance the flavor and softening it.
Older and vintage red wines as they age, they naturally produce sediment, while white wines rarely produce sediment. Stirring up the sediment when poured, results to bitter flavors, cloudy appearance and gritty texture. And the wine will become less enjoyable, but not harmful.
Particularly fragile or old wine, especially 15 or more years old, should only be decanted for 30 minutes before serving. For younger, full-blooded red wine and even white wines, they can be decanted for 1 hour before serving. In some wine tastings, their wines are decanted for hours before serving and still taste delicious.
It's fun to experiment decanting wine. Aside from removing sediment, it's really more on about personal preferences. You can buy your own decanter, and try decanting some types of wines and see what happens. Some people find pleasure from just pouring wine from a decanter to their wine glasses. Or just enjoying the “show” of it.