Storing an open wine bottle is always a delicate matter because Oxygen turns red wine quickly into vinegar. The key is to reduce the amount of oxygen touching the surface when storing open red wine. There are few methods used to prolong shelf life, all based on minimizing exposure to oxygen either by replacing, removing the oxygen or reducing the surface area of the wine.
Always keep the bottle upright.
Do not put it on its side on a rack. Since oxygen is the enemy of wine, having the bottle upright provides less surface area to come in contact with the oxygen in the bottle.
Place your bottle with the cork in the fridge.
Due to the cold temperature, oxygen is not able to inflict the same damage at the same speed, so place your bottle in the refrigerator.
One great way to eliminate oxygen from opened bottle is by pouring the leftover wine into smaller containers. One of the biggest threat to wine is surface area. The more wine in contact with oxygen the more quickly It will start to degrade. If you’ve only drink half a bottle of wine, this means the leftover wine in the bottle is now expose to a half bottle of oxygen.
One way to remove oxygen from an opened bottle is to put another gas into the container. By pumping in a gas that is heavier than air, it will force the oxygen out of the bottle. Once the gas is inside the bottle, cork the wine immediately. The replacement gas usually does not alter the taste of wine.
You can pump the air out. Several hand pump and rubber stoppers are available in a wine shop or online.