Their average life expectancy is approximately 15 years. From this age on they start to "age", and break up easily. And after ten years of use they progressively start to lose their elasticity and their natural moisture content.
On drying out, microscopic cavities forms which become breeding grounds from mould. The mould ends up transferring the characteristic "corked" aroma to the wine. A "corked" wine is one that has been spoiled by a cork contaminated by "Trichloranisole", or TCA, which can be detected at concentrations of just a few parts per trillion. It affects the wine, giving it a musty, dank, mouldy smell and an off taste.
Chlorine solutions used to sterilise corks have been found to encourage the production of TCA. This is the most common wine fault and can occur at the rate of one in 20 bottles opened (not at such a high rate for fine wines). This has stimulated the development of stoppers made from types of plastic, agglomerate cork and even screw tops.
Cork floating in the wine does not mean it is corked. It is a sign of a dried out cork or it could simply be that the bottle has been opened poorly. Mould on top of the cork is nothing to worry about either.

Contact with air, or "oxidization", spoils wine and is caused when a wine has been open for too long, has an ill-fitting cork or is simply too old. It is easy to spot; on the nose the wine will have a sherry-like smell and will taste dull and lifeless. Red wines will be dull brown in color, and White wines will turn a tawny or brown color.

Wine does not deteriorate because of the glass, however, its structure is modified.
Wine, when stored, can accentuate the characteristics it had before being bottled. And it is exactly these features acquired during its ageing in bottle which highlight some of the traits which will determine its quality.

The tannins from the grapes and the wood are rounded, reducing the primary characters (those from the original fruit) and increasing the notes which give the wine the hints of nuts, spices and wild herbs.

Light, heat and oxygen, depending on the amount of contact with the wine, produce a slower or faster evolution in the wine. The higher the temperature, the faster the wine evolves. The slower the evolution of the wine, the more harmonious the combination of the flavors of the grapes and those flavors acquired in the fermentation and maturation phases will be.

The size of the bottle also plays an important role in the evolution of its contents. Although the image of wine is that of 750ml bottles, widely used because they are easy to handle, wine is better protected in larger volumes.
Larger capacity glass containers retard the evolution of the wine, developing a wide variety of nuances which would have been lost in smaller containers.
The larger the container, the longer the life of the contents.

You will quite often spot clear crystals that look rather like sugar in the bottom of a bottle or glass. Sometimes the crystals attach themselves to the cork if the bottle has been stored on its side. They are "Tartaric Acid Crystals" (also known as "Tartrates") and are neither harmful to the drinker or the wine.
Tartaric Acid is a natural component found in grapes, and therefore wine, that crytalises when wine becomes very cold, or if the wine is old. Tartrates are usually a sign of a quality wine that has not been over-treated during vinification.
It is possible to ensure that the Tartrates do not form by filtering the wine prior to bottling. However such aggressive filtration is a more common practice in the making of bulk-produced wines because it can also strip a wine of its flavor.

The smell and/or taste of vinegar indicate that a wine has either been badly made or the bottle has been open for too long and has been attacked by a bacteria, called "Acetobacter". Acetobacter reacts with oxygen and this reaction changes the taste of a wine to a vinegary flavor. In fact, this is how vinegar is made. This fault is also described as "volatile".

Sulphur Dioxide (SO2) is the most common chemical used in winemaking. Almost every wine is made using this compound because it helps prevent oxidization and stabilizes wine. Careful winemakers use it judiciously because an excessive amount of SO2 causes disagreeable aromas in the wine.
Within the EU there are maximum permitted levels that may be used. SO2 is detected by a smell reminiscent to struck matches or bad eggs and may cause an unpleasant tingling sensation in the nose. However these wines will not be harmful, just unpleasant.

If it is a blue fish there is no problem and neither is it a sacrilege to have a light bodied young red wine, up to three years old, with fish such as turbot, cod and other delicate fish if they are garnished or have a strong sauce. Meat or fish, game or meat on the grill, fish done in the oven or in a casserole. Each dish demands a certain type of wine and vice versa. Full bodied reds need a heavy meal; delicate meals on the other hand need lighter wines, no matter whether they are young or aged.

The wine changes or worsens. A wine changes because it gains some attributes (becomes more supple, more spicy aromas appear), and it loses or harmonizes others, such as the character of the grape and some sensorial element of the terroir (soil and climate)

9 Does wine suffer when transported ?

Nowadays wines are sufficiently stabilized to undergo any onslaught. Only the flavors and the aromas get blocked (short aroma, without expression) in the days following the trip. After a fortnight they will have recovered.

10 Why do they usually use red grapes in champagne and the color of the wine is white?

Because they extract the must very quickly with very wide and shallow presses so that the must is not in contact with the skins long enough to be stained. Even so, the color of sparkling wines sometimes has reddish reflections.

A red wine should be drunk at between 16°C and 18°C; white wines are more expressive between 8°C and 10°C and roses at about 12°C Because they extract the must very quickly with very wide and shallow presses so that the must is not in contact with the skins long enough to be stained. Even so, the color of sparkling wines sometimes has reddish reflections.