How long can a wine last after opening?

Wine will begin to change as soon as it comes into contact with
oxygen so if you don't finish a bottle in one sitting be sure to
replace the cork or screwcap. Storing wine in the fridge also seems to
slow the oxidization process.

In some cases a wine can taste better the day after it was
opened, while in others it can "lose" fruit structure and become a bit
flat on the palate.

As a general rule of thumb however, wine can continue to be
drunk for several days after opening, but again, this depends on the
wine as some will hold up better than others.

How long will a certain wine last before it needs to be drunk?

It's a tough question to answer. So many variables are involved,
including the grape variety, wine style, quality of the vintage,
quality of the producer (and their track record for making wines that
go the distance) and the storage conditions the wine is subjected to by
the purchaser. Good storage conditions will go a long way to prolonging
the life of a wine.

If you want to get serious about keeping some of your wine long
term, do your homework on the potential life of the wine beforehand -
particularly if you want to purchase more than a couple of bottles.

If you buy a case of wine you can drink it over a period of
time and see how it is progressing. If it's still quite aggressive or
tannic leave it a while longer, or if you think it's ready, drink it
now.

If in doubt, drink it sooner rather than later - as a wine that
still has potential is much more satisfying to drink than one that's
past it.

What's the difference between New World and Old World wines?

The term "Old World" refers to the traditional European home of
wines that have been produced for centuries - such as France, Italy,
Spain and so on. "New World" refers not to the supermarket chain, but
countries such as New Zealand, Australia, South Africa and the Americas
that have been producing wines in more recent times only.

Common observations of the differences between the two styles
are the "Old World" wines are more savoury, lower in alcohol and bound
by more rules regarding the growing and making process.

"New World" wines are often described as fruity, fresh, and more diverse (and dynamic) in their production techniques.

What causes cork taint?

Corked wine emits a musty wet cardboard/wet dog kind of smell,
tastes flat on the palate and can have a bitter aftertaste. The most
common cause of this taint is TCA (trichloroanisole).

This can happen as a result of natural corks being washed with
chlorine, or can originate in the winery if chlorine is used as a
cleaning product meaning even wines sealed with a synthetic cork or
screwcap can be affected.

Sometimes you may open a wine and find the cork is a bit
crumbly - this does not necessarily mean the wine is corked, rather
that the cork has just dried out a bit. Some corks can also get a bit
mouldy, but this too is generally not something to worry about.

What are "legs"?

Wine "legs" are the streaks of liquid that slide down the inside of the glass after you have swirled your wine around in it.

Put
very simply, wine is a mixture of alcohol and water and legs are
created as a result of the alcohol, "surface tension" and evaporation.

Alcohol has a lower surface tension than water and evaporates faster -
as the alcohol evaporates, water concentration increases causing the
alcohol to pull together into a teardrop that then runs down the glass.

However, legs are not generally considered a great way to gauge the quality of a wine.