Storing Opened Wine Bottles
Many regular wine drinkers find that just half a bottle of wine is satisfactory for an evenings drinking, and this level of intake does no harm to an otherwise healthy liver. In the absence of a companion to finish the bottle, drinking in moderation means dealing with the preservation of left over wine. It seems quite reasonable that we should keep the wine for the following day, but will the wine last this long? How should we keep it fresh, in the condition in which the winemaker intended it to be enjoyed?
Pulling the cork on a bottle of wine is a crucial moment in time. It is a point of no-return, as once cork has been separated from bottle, the wine is exposed to oxygen in the air, which has the potential to cause great harm. How the wine holds up as it released from its captivity depends on a number of factors, but the age of the wine is without doubt one of the most important. A young wine, say a classed growth claret of just five years of age, will benefit from exposure to the air at first. Decanting the wine into a suitable container helps to soften the tannins, and allows the bouquet to develop. Very old wines, however, are much more fragile, and may rapidly collapse, losing much of their character and bouquet within just minutes or hours of being opened.
Consequently, it seems silly to expect an old and venerable wine to survive from one day to the next. But for younger, sturdier wines which, for most of us at least, comprise the vast majority of our drinking, there are methods which may be employed to preserve the wine so that it may be enjoyed the following day.
Like all foodstuffs, wine can be preserved by placing it in the refrigerator. Chemical reactions are much less rapid at lower temperatures, and hence the process of oxidation that will eventually make the wine undrinkable occurs much more slowly than it otherwise would. Lowering the temperature of the wine also inhibits the action of acetic bacteria, which threaten to spoil the wine by converting it into vinegar. I think placing the left over wine in the refrigerator is one of the most important steps in preserving it for the following day. There are, however, techniques which go further towards preserving the wine by attempting to lessen the effect of oxygen more directly.
Shoving the cork back in a half empty bottle of wine and refrigerating goes some way to slowing its degradation. It may be better, however, to decant the wine first from the full bottle (750ml capacity) into a spare half-bottle (375ml capacity), recork it and then refrigerate it. This practice lessens the amount of oxygen in contact with the wine, there being just a small amount between the top of the wine and the cork. Some wine lovers regard this practice to be ineffectual, arguing that the contact between oxygen and wine resulting from the act of pouring it into the smaller bottle outweighs any benefit gained from the smaller volume of air in the half bottle. Thereís no evidence either way, but my personal experience suggests that there is a difference, and so I usually decant.
Going one step further towards removing the wine from contact with oxygen involves the use of a vacuum device. A specially designed rubber bung is inserted into the neck of the bottle, and a simple pump used to extract the air. This results in a partial vacuum at best, as itís quite impossible for such a simple piece of equipment to achieve anything better. I imagine this is a commonly used technique, as the necessary equipment is quite inexpensive and can be found in most supermarkets. Itís not one, however, that I recommend. My experience suggests that storing a wine using a vacuum device has a detrimental effect on the wine. When comparing wines decanted to a half bottle and stored in this way with those decanted and simply recorked, those that had been vacuumed had less aroma on the nose, and seemed flat and dull.
I think there may be two reasons for this. Firstly, when using the hand pump itís quite common to see a steady stream of bubbles rising up to the surface of the wine. This is dissolved gas, most probably carbon dioxide, coming out of solution under the reduced pressure. Such a change in the composition of the wine may quite feasibly result in a duller, less interesting wine. Secondly, I hypothesise that it may not be just carbon dioxide that is lost. Many of the interesting aromas on the nose of a wine are volatile compounds, and it may be that storing the wine under partial vacuum causes these to evaporate and be lost from the wine also.
For the serious wine lover, a quick squirt from a cylinder of compressed nitrogen can be employed to protect the wine from oxidation. This seems like the ideal solution, with no reason to suggest loss of volatile compounds, and minimal contact with oxygen as the nitrogen gas settles over the wine. Unfortunately there are mixed reports, with some suggesting that the nitrogen may have a detrimental effect, particularly on the less robust, older wines. Itís also just one more piece of kit to clutter up the kitchen cupboards. I wouldnít put anyone off trying it, but I donít personally recommend it.
One exception to the above is sparkling wine. To try and decant such a wine would be foolish, and would probably result in the loss of more fizz than would be lost as a result of leaving the wine in a half empty bottle. The use of nitrogen is probably unnecessary, as a layer of carbon dioxide from the bubbles protects the wine from oxygen. This is probably why many drinkers report little change in the character of the wine, when simply recorked and refrigerated, or even when stored in an open bottle. Many wine lovers use a pressure cap, myself included, and judging by the amount of pressure behind the cap when released Iím sure it goes some way to preserving the amount of fizz. Itís not often I use one, though. Somehow I never seem to have any difficulty finding someone to help me polish off a bottle of Champagne.
With a little care the vast majority of wines can be stored safely to be finished the following day. I would not recommend trying to keep wine any longer than this, as the above measures serve only to delay the inevitable deterioration of the wine, not to prevent it. My personal practice is to treat all still wines the same, red or white, including fortified wines such as Port. I decide beforehand how much of the wine I am going to drink that evening, and usually this is half a bottle. Immediately upon opening the wine I pour half into a 375ml bottle, seal with the cork and refrigerate. The next day I remove Port and red wines from the fridge a few hours before I wish to drink them in order that they may gently come back up to a suitable temperature. White wines generally remain in the fridge, although some come out for a short while first. Through experimentation I have found this simple practice to be the most effective method of keeping the wine well.