A prestigious wine bottle should be shared and drunk, however, there are some necessary precautions to take in order to preserve the bottle once opened. Certain wines have been kept with patience and love, it would be a shame not to finish the bottle only because it was not properly saved. Knowing how long and how to keep an opened bottle of wine is a staple for any wine lover.
The wine preservation process requires a lot of attention : bottling, cork quality, light, temperature... Once the bottle is opened, it becomes a lot more fragile : when wine is exposed to air, the ageing process speeds up. It's called oxidation. When wine is exposed to light, it oxidises and loses its aromas. Heat also harms wine and increases oxidation. When wine oxidises, its aromas change and disappear until it turns into vinegar.
White wine can be kept for 1 to 2 days top, versus 2 to 4 days for red wine. A powerful red wine might keep a while longer thanks to its amount of alcohol and tanins. Same goes for a syrupy wine and its sugar content. Finally, natural wines are pretty vulnerable to oxidation since they do not contain sulfur (anti-oxidant). It is best not to keep an opened bottle of very old wine, it is very unlikely that it will survive in the fridge.
· First of all, avoid contact with air and oxidation with the help of a cork, preferably a clean cork (not the original one)
· Keep the opened bottle in the fridge, avoiding heat and light
· You may transfer the wine into a smaller bottle : there will then be less oxygen, which can alter the wine quality.
· Acquire a vacuum pump or specially made corks in order to drive the oxygen out of the bottle.
Other more sophisticated processes are available, such as compressed nitrogen which is inserted into the bottle in order to protect the wine.
Some older or sparkly wines deserve to be properly appreciated and not (or very shortly) stored. If not possible, it is absolutely necessary to take good care of it once it is opened. For any other types of wine, it is possible to use them in cooking, a red wine sauce for example or a fish dish using white wine.