I had a chat with a wine marketing executive the other day and asked him what he thought of when he heard the phrase "a $20 bottle of wine."

He laughed and said that all depended on a lot of things, one of which was that without knowing the variety of grape, or the region the wine came from, or a lot of other things, he couldn't tell a thing from such a phrase.

A $20 Napa Valley Cabernet Sauvignon probably was not a very good wine, he said. But the same price for a Sauvignon Blanc could get you a very fine wine at a fair price.

So the phrase has little precise meaning until you add more qualifying descriptions. I have tasted a lot of very nice $20 Zinfandels, for instance, that were good wines. Conversely, I have had some $50 Zinfandels that were hard to swallow.

When you think about all the different grape varieties in the world and the multitude of regions that produce them, each grape and each region has certain pluses and minuses associated with them.

I don't see much Cabernet from the Carneros, for instance, but there is nothing that says a Cab from that region can't be very good. Yet often such wines are priced lower than they would be had they been from Rutherford.

The wide price disparity between one wine and another may seem to some people that wine pricing is based on some arcane, abstruse formula that average consumers could never understand. But there are a number of reasons why wines are priced the way they are:

— A wine can be priced artificially high to give the impression that it is really good. A tiny handful of people actually like such wines, and they are influential and have a pulpit from which they can reach a lot of acolytes.

— A wine may be priced too low because a lot of it was made and in order to sell it within a proscribed period of time (such as a year, so it will be sold before the next vintage comes out) the price is low enough to move the product.

— A wine that normally sells for a reasonable price is kept at that same price even though a new winemaker or source of fruit means that the price is far lower than the (new) quality of the wine.

— A wholesale company sees that the new vintage of a wine is being prepared to hit the market, and there is a lot of last year's very good vintage available. So the price is dropped for the last of the older vintage.

Note that in most of these cases, the quality of the wine is less an issue than are other considerations.

A classic case in point is how many retailers and wholesalers treat older white wines - with fear and disdain.

White wine doesn't age, goes the old saying. But in some cases, that is absurd. With certain kinds of wine, older is better - dry Riesling, for instance. I have often had some superb Rieslings in which the wine developed a sensational character after many years in the bottle.

Not all Rieslings develop this way, and for those that do not, dropping their prices to move them out is a valid idea. But to do the same with Rieslings that have aged well is a waste of a resource.

If a merchant or restaurateur has no one on staff who can tell which Rieslings are merely old and tired, and which are improving, he or she will not know which direction to go.

The bottom line here is that often the price of a wine is no reflection on its quality.

<em>Dan Berger lives in Sonoma County, where he publishes "Vintage Experiences," a weekly wine newsletter. Write to him at winenut@gmail.com.</em>