Wines are made from hundreds of different grape varieties, each one imparting specific characteristics. In some regions, one grape variety is used to make a wine; in others, winemakers blend several varieties in a single wine. Here are a dozen of the world's best and most widely used grape varieties. For each one, I will discuss what wine people call "varietal character," or the special qualities of the grape.

White Wine Grapes

Chardonnay. The hottest grape for white wines among American wine aficionados, Chardonnay is low in varietal character--that is, the grape itself does not have immediately recognizable, identifiable flavors. It ripens well, meaning that the wine can be rich, a little sweet, high in alcohol--all things that the American wine-buying public seems to like. It takes beautifully to a range of barrel techniques, such as fermentation in the barrels and the stirring up of yeast, which ultimately give the wine flavors not derived from the grape itself. So when you open a Chardonnay, you may smell and taste tropical fruit (pineapple often appears), bubble gum, toast, vanilla or spice (such as clove). My favorite Chardonnay flavors are earthy-minerally, often derived from the chalky soil of Burgundy (especially Chablis, a French village in Northern Burgundy that turns out spectacular Chardonnay-based wines). A great white Burgundy (which is made from the Chardonnay grape) grown in a top vineyard and made by a master winemaker can be a complex delight when aged for ten years or so.

Sauvignon Blanc. This grape is easy to identify in a blind tasting. What's hard is finding the words to describe it. When Sauvignon Blanc is grown in a cool area, the resulting wine is herbal, even vegetal--some of the world's Sauvignon Blancs suggest canned asparagus. Sometimes a quality creeps in--trust me, this is attractive--that is reminiscent of sweaty clothes left in a gym locker. Winemakers often try to eliminate the varietal character of Sauvignon Blanc, which not everyone likes, by letting the grapes get very ripe, which gives the wine more general fruit qualities. Too bad. These days, even Sancerre (France's classic wine made from Sauvignon Blanc grapes) often doesn't taste "green" enough. The gap is being filled by Sauvignon Blancs from New Zealand, and some good ones from South Africa.

Riesling. In the 19th century, Riesling--not Chardonnay--was commonly considered the world's greatest white wine grape variety. Why? Because it's capable of making wine that really has "breed," as wine writers like to say, also described as "elegance" and "refinement." It doesn't taste hot, fat, flabby or "out of control" in any way. When Riesling is good, it combines a whole range of fruit flavors with a steely acidity that keeps the wine taut, which means crisp and low in alcohol. Young Riesling wines can smell like peaches, mint, lime, honey; as they age, they begin taking on desirable "petrol," or gasoline-like, tones. To Riesling freaks, the appearance of these minerally scents is cause for celebration. You may have heard that all Riesling wine is sweet. Not so: Much of the Riesling made in Germany and Austria is actually dry. In addition, some of the world's greatest dessert wines (such as Germany's Eiswein and Trockenbeerenauslese) also can be made from Riesling.

Gewurztraminer. The one grape that most wine-lovers would immediately flag in a blind tasting is Gewurztraminer, because its aromas and tastes are so distinctive. Unfortunately, describing it is not as easy as identifying it. Most wine people know that "wurz" means "spice," and therefore blithely describe the varietal character of Gewurztraminer as "spicy." But it doesn't really smell like any spice I know. The most powerful olfactory reference, for me, is fresh lychee fruit. Many proclaim that Gewurztraminer is the perfect wine for spicy food. But beware -- Gewurz can be bitter and high in alcohol--two qualities that don't play well at all with food that's "hot" with spices. To make things even trickier, most Gewurztraminer produced in Alsace, the home of the world's best Gewurz, is dry, but not all of it is so. In California, on the other hand, most of it is lightly sweet. Bottom line: Be really careful when matching Gewurz with food. It's an exciting stand-alone wine, but not a high-odds proposition at table.

Trebbiano. This grape is included by dint of its ubiquity: It is the Italian grape for white wine. It is planted all over the Italian peninsula, and is used for everything from Soave, the famous white wine of the Veneto region, to balsamic vinegar. Is it good? Not particularly--especially if you're looking for great varietal character in your white wine. It is, however, pleasant and serviceable. Trebbiano can create crisp, clean, light wines that are terrific partners for all kinds of Italian dishes. One of my favorite wines from Trebbiano is a super-light, highly refreshing Tuscan white called Galestro, which gets no respect in the U.S. but is guzzled by the ton in Italy.

Pinot Gris. Most Italian wines from this grape variety have the Italian version of the name, Pinot Grigio, right on the label. As it's made in Italy, however, Pinot Grigio (or Pinot Gris) doesn't have a great deal of varietal character. Move over to France, on the other hand, and you can see why wine-lovers sometimes rave about Pinot Gris. In the vineyards of Alsace in northeastern France, Pinot Gris is a different creature altogether. It's a much heavier, riper, more explosive wine, with some of that high-octane melon and spice that belongs to Alsace alone. This wine is not particularly flexible with food, but it is wonderful for a cold terrine of foie gras--a match served thousands of times a day in Alsace.

Red Wine Grapes

Cabernet Sauvignon. If Chardonnay is the vanilla of today's commercial climate, Cabernet Sauvignon is the chocolate. These two "flavors" dominate wine lists and wine shops in America. Historically, Cabernet Sauvignon is the major grape variety used in the great wines of Bordeaux's Medoc region in western France, and all the textbooks say that these wines are the world's greatest reds. Cabernet Sauvignon is easy to pick out in a blind tasting--the varietal character, like that of the white Sauvignon grape, has to do with herbs and vegetables (bell pepper is a favorite taster's image). But great Cabernet goes beyond that; in youth, it often includes divine whiffs of red fruits, such as raspberry. As it ages, good Cabernet Sauvignon gets even more interesting, picking up a whole spectrum of aromas--of which cedar, or "cigar box," is the most classic. Because top-quality, expensive Cabernet Sauvignon can be fiercely tannic in youth, it often needs 15 to 20 years to shed its tannins, develop deep flavor and reach its best.

Merlot. Merlot is another grape in the classic Bordeaux blend. Because the textbooks say Merlot is used to "soften" Cabernet, a myth spread: Merlot is the soft one, round and gentle, not tannic. It is true that if you grow Merlot a certain way in certain places, it will fit that profile. But you can grow soft Cabernet, too, and you can grow a tough Merlot. In fact, Merlot's varietal character is not far from that of Cabernet Sauvignon; it's easy to mix them up in a blind tasting. The tell-tale Merlot quality--look for it in wines named for the French Pomerol and Saint-Emilion regions--is a scent reminiscent of the floor of a pine forest with lots of fallen needles. Merlot, too, can be fruity, even jammy, in youth, and then can age into something complex, mysterious and magnificent.

Pinot Noir. Unlike the Bordeaux region, Burgundy, in eastern France, usually makes red wine from one grape alone, and that grape is the incomparable Pinot Noir. Pinot is more delicate and subtle than Cabernet Sauvignon or Merlot. In youth, the emphasis is on strawberry-like and cherry-like red fruit (not on herbal qualities as in Cabernet); experienced Pinot-spotters sometimes look for a whiff of geranium as a Pinot clue. In youth, Pinot--though it can be tannic--is rarely as austere as Cabernet; much Pinot Noir gives pleasure after two or three years of aging, while many Cabernets need many more years to be palatable. When a great Pinot Noir that is meant to age reaches its climax--the best ones can easily go 15 or 20 years--you have one of the most extraordinary experiences in all of wine. Some hints of cherries and strawberries may remain, alongside the orgasmic array of earthy, animal-like, erotic, truffly aromas that defy description (and would defy a censor).

Syrah. One of the greats of southeastern France's Rhone Valley, Syrah is a grape with power and weight. Syrah is the backbone of such thick wines as those from the French appellations of Cote Rotie, Cornas and Hermitage. Often quite dark and purple in youth, textbooks call it "peppery," as in freshly ground black pepper, but I find it more animal-like, or "sauvage," as the French like to say, meaning "wild," actually smelling like wild animals. A nice feature of Syrah is that less expensive examples of it, such as those from St. Joseph or Crozes-Hermitage, can have complexity and give pleasure after only three or four years in the bottle. The really great Syrahs--such as Hermitage from a great producer in a great year--can evolve for decades into the same kind of indescribable nuance and mystery that old Cabernet Sauvignon or old Pinot Noir can yield. Much Syrah was planted in California in the '90s, and Shiraz--the Australian name for Syrah--is the workhorse red grape of the Australian wine industry.

Zinfandel. Though no one knows exactly where this grape came from--the current belief is that it is a transplant from Puglia, in southern Italy--it is indisputably California's grape today, with almost no winemakers in other places producing it. It's actually made in a variety of styles in California, from elegant to brutal. But the quintessential Zin-ness always comes through: Red fruits and berries, but with a wild, zesty, almost minty aroma that's often called "brambly." You simply have to try it to get a sense of its varietal character. Try a bottle not more than three or four years old, because that's when the Zin character is strongest.

Gamay. The grape of southern Burgundy's Beaujolais region is a heck of a lot simpler and less important than the other grapes on this roster. But why hold that against it? When you're drinking wine every day with your meals, "impressive" gets tired fast. The aroma of young Gamay (most Beaujolais is consumed within one or two years of harvest) is unmistakable: A lighthearted wave of cherry-strawberry fruit sweeps over you, sometimes joined by something so sweetly, irrepressibly fruity it smells like ripe banana. On the palate, Gamay wines are bright, reasonably crisp with acid and moderate in alcohol, with little noticeable tannin. In other words: Wines from Gamay grapes are ideal for all kinds of foods. There are a number of grape varieties in California with "Gamay" in their names, but none are the true "Gamay" of France's Beaujolais region.

-David Rosengarten