What makes some bottles more expensive than others? And beware: There may be ingredients other than grapes in that bottle.

1. "You're paying for prestige, not taste."
Cruise the aisle of your local wine store. Take in the various vintages and imagine the taste of a fine old Bordeaux on your palate. But before you grab that special bottle, notice the dizzying degree to which wine prices can vary, even for offerings that seem extraordinarily similar. Take, for instance, bottles of Mondavi Pinot Noir 1997 and Benton Lane Pinot Noir 1998. They both come from the West Coast of the U.S. Their tastes are difficult to discern from one another. But then look at the price: The Mondavi, which sells for $30, is almost 75% more expensive than the $17 Benton Lane.

What is such a price difference really about? In a word, prestige. "Expensive wines command high prices because they are produced in limited quantities or come from very specific geographic regions," says Vic Motto, a wine industry consultant with Motto Kryla and Fisher in California's Napa Valley town of St. Helena. Motto cites the well-known Opus One — a joint venture of Robert Mondavi and Rothschild — as an example. Opus One's 1980 cabernet sauvignon sells for a whopping $150 a bottle. "How much better is that than a $50 wine?" asks Motto. "Probably not three times as good. But it's scarce, reliable and prestigious." According to Roger Asleson, director of public relations for Opus One, that is pretty much the point. "I'd have to ask him which $50 bottle of wine he has in mind," he says. "Will it have the cachet, the imprimatur of the Rothschild and Robert Mondavi families? No."

2. "Our labels are misleading."
Seeing the words "Napa Valley" on a wine label is reassuring. The area is known for its first-rate grapes, and many of the best American wines tend to originate there. That explains why California wineries like to have their products associated with the region — even if the grapes were grown someplace far away. Such was the case with a wine called Napa Ridge, which is actually made from grapes grown in Central, rather than Northern, California. Similarly, CK Mondavi, owned by a member of the famed wine-growing family, slapped references to the Napa Valley all over the labels of its wines, which are produced from grapes grown elsewhere in California. Earlier this year a California judge fined the California-based Bronco Wine Co., makers of Napa Ridge, $750,000, and CK Mondavi $300,000 over a labeling complaint. Furthermore, a ruling is expected to come down that will make it illegal to use a geographical name on a wine label unless 85% or more of the grapes in the wine come from that region.

The folks at CK Mondavi see it more benignly. "It was just a reference to where the winery was located, and it was originally OK'd by the Bureau of Alcohol, Tobacco and Firearms," says John Garaventa, brand manager with C. Mondavi and Sons. "Apparently they changed their mind." Via written statement, Bronco says, in part, "This was one of those notorious 'gut and amend' bills that started life as one thing and got hijacked to serve a special interest" — namely Napa Valley grape growers.

3. "Our favorite wines are less than the best..."
You're sitting in a restaurant, perusing a wine list with names that seem as recognizable as an ancient Greek epic. So you ask your waiter for assistance. He immediately suggests an offering, smiles and tells you that it's one of his personal favorites. What he doesn't tell you is why. "Some wine companies offer incentives to waiters who move their products," says Anthony Bourdain, chef at Manhattan's Les Halles and author of the scathing bestseller "Kitchen Confidential" about the ins and outs of the restaurant business. "Wine salesmen spend a lot of time in their customers' restaurants," Bourdain explains. "They give away fancy corkscrews, signage, cute outfits, free cases." In other words, it's often in the waiter's best interest to push one wine over another, even if it's not the best value.

In some cases, the benefits may be too alluring to pass up. "I know of one waiter who is ferociously selling a not-very-good wine," continues Bourdain. "The vintner maintains a chateau in Portugal, and the waiters who sell the most bottles of his wine get invited to stay there. I understand that the place is a Portuguese equivalent of Hef's pad."

4. "...but you won't notice anyway."
Last year a group of British wine critics were challenged to try five wines, four of which were defective in some way, and as one of the participants, Richard Neill, wrote in London's Daily Telegraph, "Thirty of the assembled tasters didn't get a single correct answer (as to what was wrong with each wine), and not one person managed to get all five right." The results of the test do beg the question: If the experts can't tell the good from the bad, what chance does an amateur oenophile have?

Tim Kopec, wine director for the restaurant Veritas in Manhattan, reveals some sure signs that you have been handed a bad bottle. "When you smell the wine, you are looking for a flaw," he explains, adding that you should at least hope for an agreeable, pleasant scent. If the wine smells like wet cardboard, Kopec explains, that means the wine has been "corked," that is, it's become infected with a spore from the cork. If it smells acidy, like vinegar, the wine is spoiled. You should also be sure to aerate the wine with a swirl before tasting it. What if you're still not sure whether or not the wine is flawed? Says Kopec: "Ask the sommelier (or waiter) to have a taste and give you his opinion."

5. "Don't buy my wine of the week."
Ever wonder why on certain trips to the wine store, various bottles are being offered at bargain-basement prices? Sometimes wines are on sale because merchants have gotten particularly good deals on them. But often there are other motivators at work. "Some places will push a wine because they have it in stock, and it's not moving," explains Al Hotchkin, owner of the esteemed Manhattan wine store Burgundy. Hotchkin was recently at a wine tasting where one of the star attractions was a French white wine. The people putting on the tasting bragged about having purchased the wine for about half its going price. After tasting it, Hotchkin realized that it was off-price for good reason. "The wine tasted old and tired," he explains.

You should also be skeptical about those handwritten shelf tags that promote various wines — you know, the ones that promise a "velvety finish" and a "hint of blackberry" — as they may be little more than sales gimmicks. "Hopefully those cute things written that adorn the shelves were written by the wine merchant after he tasted the wine," says Hotchkin. "Less good is when the store copies it from a reputable review. The third possibility is something that I'd rather not think about." What does he imagine it might be? "Creative writing."

6. "The best regions make for the worst deals."
If you really wanted to get serious about wine, you'd spend much of your life traveling through obscure towns in France, checking out underappreciated wines from boutique growers. But because nobody has the time to do this, we are at the mercy of liquor-store salesmen who push us toward familiar wines from familiar regions that, of course, get sold at familiarly high prices. Robert M. Parker, who publishes a monthly newsletter called the Wine Advocate, cites the Burgundy Chambertin vineyard as an example. "Three wines that come out of there are stupendous, six are good and the rest range from mediocre to undrinkable," he explains. "Yet they all sell for $150 to $300 per bottle. You're paying for a legendary vineyard with a mythical reputation that often disappoints."

Fortunately, it's now possible to find good wines from little-known regions for bargain prices. That's exactly what Kermit Lynch does for a living. Lynch is a Berkeley, Calif.-based wine importer who spends half the year scouring the French countryside for unknown wines. Most recently, Lynch has had a lot of luck in the south of France. Some of his favorites? A white varietal from Domaine de la Done for $7 and a sauvignon blanc from Domaine Salvard for $9.

7. "The feds will love your wine."
The Internet seems like a fabulous resource for wine — especially for hard-to-find bottles produced in limited quantities. Unfortunately, most Internet wine retailers probably can't legally deliver to where you live. In a hangover from the days of Prohibition, most states' laws prohibit wine from being shipped interstate. In fact, there are just 12 states where you can legally and unquestionably receive a shipment. (To see where your state fits into all of this, go to www.wineinstitute.org.)

While many Internet retailers have different ways of dealing with this problem, some just ignore it; that is, they ship you the wine wrapped in brown paper, regardless of the law. Such a move may carry risks, even for you as the consumer. Explains John Hinman, managing partner at Hinman & Carmichael, a San Francisco-based law firm that specializes in alcoholic-beverage law, "You do run the risk of having the wine taken away. In Maryland, there have been a number of wine seizures, which tend to strike during the holiday season."

8. "Your wine has been spiked."
Because all wine essentially looks the same, the label goes a long way in guiding you toward what you want to drink. When something is identified as, say, cabernet sauvignon, that's what you expect to be drinking. But what if the label also promises that the wine includes "natural flavors"? You might assume that means other grapes. Nuh uh. In fact, the most likely mystery ingredients are fructose, water and alcohol.

How can the winemakers get away with it? Because laws state that while all the grapes present in the wine must be named, the specifics of any additives do not need to be listed. The whole thing is an outrage to Karen Ross, president of the California Association of Wine Grape Growers. "It's a rip-off to consumers," she complains. "When people put less expensive grapes in with, say, their zinfandel grapes (without making it clear to consumers), they get fined for doing it. But when somebody acknowledges that there are natural flavors mixed in with a known varietal wine, they are allowed to do it even though you have no idea what you're drinking."

9. "Wine is a rotten investment."
As with all limited commodities, the value of a wine grows when demand exceeds availability. That is the idea behind investing in wine futures, fancy financial instruments that allow you to buy wine years before it's produced, at a discounted price. Then, the theory goes, you will wind up with a case of wine poised to grow in value as it ages to perfection.

Really, though, wine futures are only great to buy if you want the wine to drink, since they guarantee you an allotment of the wine in question. As an investment, well, you'd be better off in the stock market. "It's pretty risky," acknowledges Jake Sobotka, a California-based financial adviser who is also an avid wine collector and a frequent purchaser of wine futures, though only for vintages that he knows he'll want to drink. "Yes, 1990 was a great year for Bordeaux, and you could have made a 50% return on your investment," he says. "But if you bought Bordeaux futures for 1992, '93, '94, '97 or '98, you actually overpaid in relation to what the wine sold for when it was released."

10. "Ignore the reviews I am touting."
Wine reviewers are everywhere, in upscale food magazines, in every newspaper and on the Web. Merchants, of course, use this to their advantage, scouring the wide field of critics to find reviews that will best help them to promote the wines they most want to sell. But don't be fooled. Those in the food and wine industry put limited stock in most of the reviews. You should do the same. Only one reviewer is regarded as being completely beyond reproach and stunningly consistent: Robert Parker, whose monthly newsletter accepts no advertising. "Robert M. Parker is the god," says Anthony Bourdain, flatly.

Upon hearing this adulation, Parker — who is partial to wines that are young and unctuous — points out that he was the first wine critic to "depart from the gravy train of being sponsored for trips and getting (four-star) treatment from the wineries. I pay my own way." Parker also believes that his signature method of giving wines a numerical score (out of 100 points) has created a level of accountability for reviewers who use it. "If you give a wine a 90," he says, "well, it better be a damned good wine."