A friend gave me a mixed dozen for Chinese New Year, mostly from the mid- to late 1990s, and in recent days we tasted half of them to see how they were faring. It was an education.

We began with a 1997 Carneros Creek pinot noir. This estate was a pinot pioneer in California. The Carneros region is in the south of the Napa valley, about 90 minutes by car north of San Francisco, and in summer it receives cooling breezes from the Pacific Ocean and San Pablo Bay.

The cork was in perfect condition and the wine, while it had peaked some years ago and was declining, was still pleasant. It was dark cherry in color with an appealing bitumen aroma. The tannins had softened, and while the wine had almost no length, it was still drinkable.

This pinot produced a lot of sediment, which is common for aged reds. Tasted the next day it was dead: oxidized and flat. The rest of the bottle went down the sink. The lesson here is to drink aged wines soon after opening and remember they are delicate creatures.

The next wine was a 1995 Bourgueil from the Lame Delisle Boucard estate in the Loire region labeled Cuvee Lucian Lame. This was their entry-level wine and not the grand wine that has won gold medals.

The cork crumbled and the wine smelled sour. It should have been consumed a decade earlier. Instead, it followed the pinot down the sink - a pity because these cabernet franc-based wines can be lovely when young.

The key issues here are longevity and storage. Some wines are not meant to be cellared and should be consumed young. This raises the question: If stelvin caps had been available back in 1995, would this wine have been drinkable now? It is impossible to know.

Some vineyards in Australia's premier cabernet sauvignon region, the Coonawarra, are doing tests, comparing stelvin caps with cork and artificial cork to see which are best for allowing wine to mature.

The same vintage has been sealed with all three closures and left for at least a decade. The tests started in 2005. It will probably be another decade before we will know the results.

Meanwhile, I prefer to buy wines with stelvin screwcaps. These may lack the romance of cork, but they ensure the wine is free of cork taint, a problem for the Australian wine industry some years ago.

The third wine tasted was a 1998 dornfelder from the St Antony vineyard in Germany. This was my first encounter with the dornfelder grape, so I needed to research it. Wikipedia tells me August Herold created the variety in 1955 at Germany's grape-breeding institute in Weinsberg.

Wikipedia also says dornfelder has good acidity and the ability to benefit from barrel ageing. It is also easier to grow than spatburgunder, the German version of pinot noir.

The cork for this 1998 dornfelder was in pretty good condition. The wine was almost black and tasted of slightly sour plums. All the tannin had been integrated. While the wine had peaked some years ago, it was still drinking well the next day.

After a break, another friend and I opened a 1995 Beringer private reserve chardonnay from Napa in California.

Beringer has pedigree. It is the oldest operating wine in Napa, having opened in 1876. The Beringer bothers chose the Napa region because it looked like the terroir they knew from home, Germany's Rhine region.

The brothers wanted to create tunnels in the hills on their property to store wine. The task of digging the tunnels went to Chinese workers who had returned to the area after helping build the railroad across the US. The tunnels took many years to complete but are the perfect place to store wine.

The cork in this chardonnay broke as it came out of the bottle so I had to push the remainder into the wine, meaning I needed a sieve to remove crumbs of cork.

This wine received at least a year in French oak, which may explain why it was so well preserved.

It tasted of dried coconut, with aromas of dried apricot. The color was dark gold, and it still retained a touch of acid. It was drinking well the next day, and matched well with an overly ripe French brie.

In December, Parker's Wine Spectator rated the 2009 Beringer private reserve chardonnay No 40 in its list of the top 100 wines for the year. The Beringer pedigree means I will seek their wines in the future.

Sadly, I cannot report positive things about the 2001 Nepenthe pinot gris from the Adelaide Hills of South Australia. The cork looked all right but crumbled like ash from a cigar as soon as the corkscrew entered. The wine tasted of nothing and went down the sink.

The 1994 Pendarves verdelho from the Hunter Valley of Australia also had a dodgy cork. But the wine somehow survived. It was dark gold, tangy yet dry, with a range of subtle flavors. Verdelho was once used to make fortified wines like madeira, and it is rare to find a table wine from this grape.

Pendarves Estate was started in 1986 by Dr Philip Norrie, a winemaker and doctor famous for his research into the relationship between wine and health. He published a booklet called Wine and Health.

So we come full circle, if you have read earlier wine columns about wine and health. What's the lesson here? Old wines can be wonderful but only if they have pedigree and have been stored well. Otherwise, they should be drunk young.