Sometimes a bottle of wine does not get completely consumed during a single sitting and might need to be preserved for another day. We might go so far as to say that this is a common occurrence, as people seek to enjoy wine sensibly and safely. Enjoy a glass of wine with dinner, and then another glass a couple of days later. But how long can you keep wine for once the bottle has been opened? Read on to find out the science behind the wine, what is happening when the bottle is open and how you can make your wine last for longer.
What happens when a bottle of wine is opened?
As soon as you pull the cork or open the screw cap of a bottle of wine, you are exposing the contents to the oxygen in the air. Oxygen is both the friend and foe of wine. Winemakers might make use of oxygen, for example, in the maturation process of their wines. By allowing a small amount of oxygen to access an aging wine in a controlled way, say through the gentle permeation of air through an oak barrel, the flavors of a finished wine are developed and changed.
In the immediate term, just as you are about to drink the liquid, the addition of a little oxygen is a good thing. It can help the wine to open up, allowing you to more easily perceive the complexity of flavor and aroma. That is why people advocate opening a bottle in advance to let it breathe, why people swirl the wine in their glass before they drink it and why there are so many gadgets and gizmos on the market to help you aerate your wine as you serve it.
However, once you have opened a bottle of wine and you want to enjoy its contents at their peak of condition, you are working with a limited window of time. The oxygen that helps your wine to open up and taste better is also slowly oxidizing it, a process that will eventually flatten its fresh and vibrant flavors, and ultimately turn it into undrinkable vinegar. That is because a chemical reaction is taking place. The ethanol (alcohol) in your wine reacts with oxygen to become acetaldehyde, and eventually acetic acid will form. So how can we protect against this?
How long is the window?
From pulling the cork to the wine being spoiled, you are only likely to have 3 to 5 days. It may take a little longer for enough acid to form that the wine tastes of vinegar, but after 5 days it will certainly no longer have the character and balance intended by its producer. This refers to wine that has been stored with the cork put back in the bottle and kept in the fridge too. The window would be shorter for an open vessel and one stored at an ambient or fluctuating temperature.
Fuller-bodied wines and mature wines that have already been exposed to oxygen during their production will also tend to oxidize slightly faster than wines that have not. This means that your fresh, young, and fruity white wines and rose wines kept in the fridge will retain their integrity for a little longer – you might hope for 5 to 7 days for a bottle in the refrigerator.
How to keep the wine fresh
Replacing the stopper that the wine came with will help preserve freshness a little, but the seal will no longer be airtight. It can push the damage back a little, but it will not stop it entirely. Very few things will create a perfect seal to prevent oxygen from reaching your wine entirely (after all, the air around us is 21% oxygen) but you can use a more effective seal to increase the longevity of your beverage. This might be a simple wine stopper, or you might buy a stopper that makes use of vacuum technology to remove the air from the bottle and keep it away from the liquid. The most effective and sophisticated method, but can be the most expensive, is using a wine stopper system that adds a blanket of gas over the leftover liquid to prevent any oxygen from reaching it at all. This is most often argon gas which is inert and safe.
Keeping your wine in the fridge once it has been opened, as already mentioned, is also the best place to prevent it from spoiling more quickly. However, with bold reds, you might not want them to be chilled down so far, in which case a cool, dark place is a better middle ground – although this is likely to mean that you can only expect around 1 to 3 days before those wines spoil.