For a long time we couldn’t understand why the French didn’t join the crowd and simply put the grape variety on its label. Why did consumers have to guess what grape was used for a wine from Sancerre or Beaujolais?

Then came several weeks of tasting chablis made by producers like Vincent Dauvissat, Domaine Laroche and Domaine William Fèvre. Now we understand: There is chardonnay, then there is chablis. They are not the same.

The most noble and prolific white grape, chardonnay is grown in just about every wine country. It commands the world’s attention because of its familiarity across borders, and for the winemaker it is an indispensible moneymaker. But chardonnay’s character varies from region to region. Even within California, the grape’s profile can stretch from tropical fruit to apples, buttery to crisp and simple to complex.

But it is in Chablis, where Cistercian monks first made wine in 865 A.D, that chardonnay turns elegant, a quality that unfortunately not everyone appreciates because its fruit is more subtle. These wines are bone dry and absent the butteriness that characterizes chardonnay made in Australia and California.

It wasn’t until the 1960s that the chablis market was really established and by then American consumers were associating “chablis” with Gallo and other jug wine producers. As consumers became more knowledgeable, chablis emerged as a special wine made only in France.

Several weeks of tasting real chablis increased our appreciation and our understanding of why these exquisite chardonnays are so special.

“Chablis is the purest expression of chardonnay,” says Gerard Boyer, a national sales representative for Domaine Laroche. “It is an elegant wine, distinctive and with natural minerality — very important.”

Its unique qualities became evident when we served a wine from Burgundy’s Meursault region alongside a William Fevre chablis. Chablis is the northernmost district in Burgundy. Both wines are made from chardonnay grapes, but the meursault — one of our favorite white wines — was fatter and more creamy while the chablis was austere and minerally with fresh acidity.

Boyer attributes chablis’ unique characteristics to two influences: Ancient soil and a continental climate. The Kimmeridgian subsoil is one of a kind and gives chablis its mineral notes. The region can get frost as late as May, and it is not uncommon to see sprinklers and heaters in the vineyards to protect the grapes.

Moderate summer temperatures hold down the sugar, so the wines are never high in alcohol. Plus, they have natural acidity. A very hot 2003 vintage shows what can happen when temperatures soar: the wine didn’t have the balance or the acidity. One has to wonder what influence global warming will have on the region.

The natural acidity and unique flavors allow chablis to age so gracefully — not something many white wines can do. We tasted a 2004 William Fèvre Les Preuses, a grand cru, that was extraordinary with just a few years of age. It could easily age another decade. As the wine ages, its texture rounds off but the acidity and flintiness remains.

Chablis is divided into four appelations: Petite Chablis, Chablis, Chablis Premier Cru and Chablis Grand Cru. Prices range accordingly.

Here are some of the great chablis we tasted:

• Domaine William Fèvre Chablis Champs Royaux 2007 ($25). Very generous aromatics redolent of white peach, honeysuckle and citrus. Good mineral note that is classic for chablis and fresh acidity with just a touch of oak.

• Domaine William Fèvre Premier Cru Montmains 2006 ($40). Subtle lime and herbal aromas followed by a flinty and citrus flavor.

• Domaine Laroche Chablis Saint Martin 2006 ($30). Sporting a screw cap — thank heavens, French wine producers are gettting it — this crisp chablis is perfect with seafood. Elegant with citrus aromas, good acidity and a thin mineral component to match the subtle tropical fruit flavors.

• Dauvissat Vaillons Premier Cru Chablis 2006 ($92). Tom visited with the Dauvissats in their cellars years ago and knew then that this wine was special. Since then their prices have skyrocketed, but the wine remains one of the best and most coveted in the region. This old-vines chablis is full bodied with fresh acidity and citrus apple notes with a solid mineral component. Dauvissat’s profile is different because of a more obvious oak component.

• Maison Faiveley Chablis 2006 ($32). Grapefruit and lemon notes with long finish and rich texture.

• Josephine Dubois Premier Cru Montmains Chablis 2006 ($21). Elegant, balanced chablis with apple notes, mineral and fresh acidity. Very nice for the price.

• Joseph Drouhin Chablis 2006 ($23). This reasonably priced Drouhin has a fragrant nose followed by citrus notes and a hint of mint. Unique.