Maybe it started in 1999 with Fritz Knipschildt’s $250 Madeleine, a French Périgord truffle wrapped in dark chocolate. Or perhaps it was in 2000, when Jacques Torres brought his eponymous chocolate factories and shops stocked with $150 gift boxes to New York. Or in 2006, when French chocolatier Valrhona launched its limited-edition Porcelana de Pedregal, 11 ounces of chocolate made from the rare Criollo bean, molded to look like a cacao flower and priced at almost $80. (Gourmands were incensed when the run ended in mid-2007, and Valrhona is contemplating bringing the chocolate back in another form.)

Once simply the stuff of Easter eggs and Hershey bars, chocolate has become a foodie fetish. It’s sniffed and paired, judged for texture, aroma, and subtleties of flavor. Chocolate isn’t just chocolate anymore—it’s limited-edition, 64-percent-cocoa bars from beans harvested at a single estate in 2005. If Willy Wonka were a real person, he’d be out of a job.

For the past half-century, most of the chocolate sold in the U.S. came from relatively inexpensive cacao beans, usually harvested in West Africa, Malaysia, and Indonesia. Over the past several years, however, finer stuff—made out of pricier and rarer beans from tiny plantations in South America or the Caribbean—has hit the market.

“Chocolate companies started making chocolate available to the public that was similar to what French chefs were using,” says Gary Guittard, president and C.E.O. of Guittard Chocolate in Burlingame, California. The public responded so strongly that the prices of some cacao beans have more than doubled during the past year.

Making chocolate is no simple undertaking—cacao beans must be harvested, fermented, dried, shipped, roasted, shelled, crushed, and mixed with vanilla, sugar, and sometimes milk. Then the cocoa passes through a refinery before the chocolate is heated and poured into molds. Some days, it seems that choosing chocolate is just as complicated as making it—but not with our sweet advice.

The Basics: Chocolate comes in three main forms—dark, milk, and white. Dark chocolate contains less sugar and milk, so it tastes stronger and appears darker. Milk chocolate has a much lower dose of cacao, tastes milder and sweeter, and appears coffee-colored instead of dark brown or black. High-quality white chocolate, from companies like Ghirardelli or Valrhona, contains a high percentage of cocoa butter, which is what makes it smooth, but no cocoa solids. White chocolates from cheaper brands often contain no cacao product at all.

The Need-to-Know Number: Among dark-chocolate lovers, the percentage of cacao in the bar, usually indicated on the wrapper, is something of a snob index. While 70 percent is currently trendy (meaning 30 percent of the bar is composed of other ingredients like sugar, vanilla, and lecithin), bars are available with cacao content as high as 100 percent. (A sharp snap when you break a dark-chocolate bar is a good sound, since more cacao content means a harder chocolate. A smooth texture is also an indicator of quality, since the best chocolate is “conched,” or refined, for as long as three days to make sure there’s no grittiness.) The more cacao, of course, the less room for sugar, so these bars are intense-tasting, almost bitter. If that’s not your thing, don’t feel déclassé: Many experts argue that sugar brings out chocolate’s flavor.

The Bean to Beat: Commercial chocolate is made from three kinds of cacao beans: Criollo, Forastero, and Trinitario. Connoisseurs know to look for Criollo chocolate, usually touted on the label; the beans are the most prized because they produce light, aromatic, nutty, caramel-colored chocolate and sell for up to $15,000 a metric ton. The best Criollos grow in microclimates in Venezuela and Colombia. Forastero beans are used in 80 to 90 percent of the world’s chocolate. Their candy is heavier than that made from Criollo, and it can be bitter. These beans generally cost less than $1,900 a metric ton. Smack in the middle, genetically and economically, is the Trinitario bean, a hybrid of the first two. First grown in Trinidad, Trinitario is now found all over the world and sells for between $1,900 and $5,000 a metric ton.

The “Organic” Gimmick: Don’t fall for products—even from high-end chocolatiers—labeled “organic.” The beans may have been grown without pesticides, but nearly all commercial chocolate beans are sprayed with methyl bromide at the shipping port, at the factory, or both, to remove insects and dirt. To ensure your bonbons are pesticide-free, look for brands that say “nonfumigated” instead.

The Singular Sensation: Single-bean chocolate bars (like single-bean coffees) are all the rage. The trend started when small farms, especially those in Brazil, the Dominican Republic, and parts of Venezuela, started producing exclusive-derivation bean shipments, meaning the beans all come from a small grove of identical trees within a certain area. “Each microclimate has beans with particular genetics,” Guittard says, “and each climate creates a specific flavor.” Some beans make peppery chocolate, others make earthy chocolate, and others make chocolate tinged with vanilla, depending on the biology of their surroundings.

The Good Save: Chocolate can be stored for well over a year, provided the spot is cool and dry and the temperature is constant. Changes in temperature result in a “bloom”—white patches that make chocolate look moldy but are just the harmless result of cocoa butter coming to the surface. Make sure chocolate is wrapped and stored away from pungent foods, as it absorbs flavors. If the chocolate crumbles instead of melts in your mouth, it’s either old or of poor quality.

The Payoff: To best enjoy chocolate, eat it at room temperature: too cold and it’s waxy; too hot and it melts. The best chocolates melt quickly—the human body is just warmer than the melting point of chocolate—and have a powerful aftertaste. For a diverse tasting plate, assemble chocolates from different growing regions and compare, as you would with cheese; dried fruit (like apricots) and nuts (like almonds) make good accompaniments.