Do you want to buy wine made the year of your childs birth to stash away and crack open on their 18th or 21st birthday?

But which wines are worth keeping, and what's the best way of keeping them so they develop slowly and are still good after all those years? Well, when it comes to keeping wine long term, you need to consider the crucial elements of acidity (in white wines) and tannin (in red wines).

Both acid and tannin are found in grapes - acid in the grape juice, tannin in the grape skins. They act as preservatives, but also, over time, change to form distinctive and hopefully delicious bottle-age characters. So minute amounts of the acid and alcohol in white wine, for example, combine over time to make toasty, nutty flavours. In red wine, the harsh, dry tannins of youth drop out of solution as the wine ages, resulting in the powdery sediment you find in older bottles, and making it taste smoother and mellower.

Traditionally, vintage port was the wine of choice for birthdays because it is both very tannic and also sweet (sugar also acts as a preservative). But tastes change, and vintage port is no longer fashionable, although by the time your kids turn 21, it may well be back in vogue.

By contrast, sparkling shiraz - another wine that develops well in the cellar due both to its sweetness and the preserving carbon dioxide - is fashionable now, but may not be in 20 years.

Full-bodied, tannic reds, such as Barossa shiraz and Coonawarra cabernet, are more likely to be options for the modern wine buyer. Another less-obvious option is white wine: crisp, lean whites such as Clare and Eden Valley riesling, and Hunter Valley semillon are excellent choices for long-term cellaring, as they have proven track records, and can drink beautifully over two decades.

Whatever wine you choose, though, try and buy it in larger bottles, such as magnums (1.5 litres), which hold twice the amount of wine as a normal bottle. Wine ages more slowly in bigger bottles. So wine in a magnum has a better chance of still being drinkable and delicious 21 years from now.

When it comes to ideal storage conditions for your wine, try and meet as many of the following criteria as possible.

1 Stable temperature
If the temperature fluctuates too rapidly from day to night, from week to week, corks can shrink, the bottles can leak and air can get in.

2 Cool temperature
The cooler the storage space, the more slowly the wine matures - between 12 and 15 degrees Celsius is ideal.

3 Humidity
If the air is too dry, the corks can dry out and shrink, the bottles can leak and air can get in. The ideal humidity is around 75 per cent.

4 Keep bottles lying down
If bottles are left standing for too long, the corks can dry out, shrink and ... well, you know the rest.

5 Keep long-term storage wine as far away from you
A friend's place (especially if they've got a proper cellar), or with one of the increasing number of professional cellaring companies. That way you won't be tempted to crack open the Grange at the end of a long, boozy evening.

Source:Better Homes and Gardens August 2005