After fielding questions about bottles, the next question I am often asked concerns the cork.

Cork comes from the bark of an oak tree which is first harvested when it is 25 years old and thereafter every nine years. A tree can be harvested 13 to 18 times during its life.

Most of these trees grow in France, Spain and Portugal with Portugal being the biggest producer. At one time the impression came about that cork supply was failing and would one day be limited. This is not the case.

Before moving onto the various ways cork has evolved during the years, I can never resist a bit of trivia: when cork is squeezed towards its center it does not expand out towards its sides. So far, we humans have been unable to duplicate this with a synthetic material. If you apply a flame to cork it tends to char on the outside rather than burn which has led to its use in certain applications on the space shuttle.

Back to our discussion of cork and wine.

There are several problems with cork. Since it is a natural product it is not consistent. This means that if you are aging a case of wine there will be variation from bottle to bottle due just to the cork.

In addition there can be components in a cork that will negatively influence the flavor of the wine.

In some cases the cork flavor can be very subtle, simply reducing the natural fruit aromas and flavors of the wine. In other cases, it can give the wine a moldy unpleasant taste and flavor.

Needless to say as a winemaker I do not like either option.

In the early 1970's, Swiss wineries began working with a French company to develop a wine friendly screw top enclosure.

When I was in school in 1984, we tasted Swiss wines that had been bottled ten years previously with both cork and screw top closures. As Swiss wines tend to be light and fruity, we preferred the screw top wine as it had not aged and still maintained its youthful freshness.

Since then screw top manufacturers have developed a membrane that allows oxygen passage, thus allowing the wine to age. This means that screw tops are now suitable for age-worthy reds.

Indeed the most expensive wine in California, Plumpjack Winery Cabernet Sauvignon, is bottled with screw tops.

Since the American public has yet to warm to the idea of screw tops, wineries have looked about for other ideas.

Plastic corks are a way to avoid the problems of real cork and still make it difficult for the consumer to open the bottle.

As you can see, I am personally biased against plastic corks as they do not allow a wine to age. In my opinion we should either use real cork or screw tops.

A New Zealand winemaker once proposed that we pretend we had always used screw tops rather than corks and that a cork salesperson was calling on the winery.

The sales pitch would be something like this, "I have a new closure for you. It will leak three percent of the time and it will negatively impact the flavor of the wine up to 10 percent of the time. In addition the consumer will need a special tool to get it out. But all this will be made up by the neat pop it makes when it is pulled out of the bottle."

Real cork will probably always be used for wine bottles.

However, it is more a matter of tradition and the pleasure of hearing the cork come out of the bottle than it is of quality. As more and more wineries begin to use screw tops, it will become accepted at the consumer level.

When this occurs then White Heron Cellars will also begin to use screw tops.