But is it really true with peaches? Can a peach be ripe but not soft? I've had soft peaches that had no flavor; were they ripe? I started to wonder about ripeness and after talking to a number of winemakers, I am not the only one questioning what ripeness is and how to achieve it.

In the past, UC-Davis and other schools of enology have argued that ripeness isn't a question of semantics; it's a question of science. Ripeness has a definition, so, to the scientist at least, something is either ripe or it isn't. That's why scientists don't always make great wine, and why there's a considerable amount of wine on shelves around the country that is absolutely correct from a winemaking point of view and absolutely worthless to many wine lovers. You've tasted them, perhaps calling them "green" or unripe – the stemmy, green bean flavors found in many mass-produced red wines, the insipid white wines that have alcohol, some sweetness, some color, but little flavor and aroma.

A couple of years ago, I took a refractometer into the vineyards of Domaine Carneros to better understand when grapes were picked. I'd read textbooks and had a good sense of benchmark figures for the elements of ripeness, primarily sugar content in a grape. It's a relatively simple device: squeeze a grape on the side of a viewing prism, correct for temperature, look through the viewer and a little scale gives you a convenient reading of sugar content. Compare that with acidity and pH, and you know if your grape is ripe. Wow, I thought, anyone can do this.

Domaine Carneros Winemaker Eileen Crane checked her own refractometer and agreed with my assessment. The sugar levels were right where we wanted them, but no one was hurrying to start picking. "Let's taste a grape," she said. It was sweet, it was juicy, it was...well, it was boring. "If I were making wine from a textbook, I'd pick now, but I think we'll wait a while longer. These grapes are only ripe with sugar, and the acidity is in the right place, but they're not really ripe because they don't have the flavors yet. Ripeness doesn't always equal flavor."

I thought about tomatoes and peaches in the grocery store that are picked early and ripen, sort of, but not really. They get soft, there is sugar there, but there is little flavor. In nature, ripening is a process of seduction, a fruit or vegetable's means to its reproductive end that depends on animals to eat it to spread its seeds. Grapes with the right sugar but not the right physiological ripeness look good but are hardly mature. They are the bimbos of the wine world.

"If you pick wine grapes based only on sugar, you get wine that has the right amount of alcohol, that vinifies well, but it may not be the wine or style you really want. This is the way wine was made in this country for years, by the numbers, like a recipe," says Sonoma-Cutrer Winemaker Terry Adams. "Having a recipe served us well because it got the American wine industry rolling," he says, but Adams also acknowledges that the recipe only went so far.

Just as polyester leisure suits may have worked as clothes but not as fashion, technocratic wines worked as experiments but not as beverages.

"These days, we are paying much more attention to what ripeness really means," says Steve Reeder, winemaker at Sonoma's Chateau St. Jean. "Just as statistics don't always tell the whole story about an issue in the news, sugar levels or other means of measuring ripeness don't really tell us everything about how a wine will turn out. Wineries can over-crop and bring in grapes with diluted flavors that are still technically ripe. I won't make any wine without tasting the grapes no matter how ripe the instruments say they are."

As the new millennium dawns, Reeder, Adams and like-minded colleagues are actually moving back in time. "This is the way European winemakers have done it for centuries," says Hogue Cellars' Chief Winemaker David Forsyth. "I think the move to technology was good because it helped build an entire industry, it raised awareness about wine and brought it into our culture, but it is equally important now to understand some traditional realities as well."

Forsyth, whose original training was in zoology, and Sonoma-Cutrer's Adams, who studied for a career in medicine, represent a new wave of winemaking experience. Along with UC-Davis-trained winemakers who learned their craft in the field after graduation as much as in the classroom, there's a new interest in tradition in California.

"It's a return to the Old World," Adams says. "It's ironic, because my predecessor at Sonoma-Cutrer, Bill Bonetti, is a generation older than I am but has a more New World approach to winemaking. Bill was more willing than I to pick by the numbers, and there's no doubt he made great wines doing that his way, but I pick more by feel and am less concerned about the alcohol-acid balance than the generation before me."

The flip side is that the Old World is still learning from the New. There is no question that many Bordeaux are now being made in a style that is more approachable at a young age, and that technological advances have brought new stability and consistency to the wines of Burgundy.

Forget what the winemakers in any country say – just taste what they make and it becomes apparent that we are increasingly living in a wine world divided less by tradition than by quality. There are over-cropped wines made in every country, just as every region is producing bottles made with care and élan. I think the market is ripe for a re-evaluation of flavor and finesse, but only time will tell.

Senior Editor Lyn Farmer produces a radio program on wine.