Most wine will taste ok for about 24 hours if left at room temperature. If placed in the fridge, the wine can taste fine for up to a week. Wine starts to degrade once it comes in contact with oxygen. There are many gadgets available on the market that can help you remove oxygen from uncorked wine bottles. If you don't want to spend money on these gadgets, you can follow two simple ways to extend the life of your wine. The simplest way would be to close the wine bottle with the cork tightly and store the unfinished wine in the fridge. You can also also transfer the wine to a smaller bottle, close it tightly and place it in the fridge. By doing so, the wine surface area exposed to the oxygen in the air would be smaller, slowing down the oxidation of the wine.