Couverture chocolate is a special form of chocolate used by chocolate manufacturers and professional bakers. This chocolate is richer and creamier than basic bar or eating chocolate, with a very high cocoa butter content which makes it ideal for things like molding, coating, and dipping. Less than 100 firms around the world produce the bulk of the world's couverture chocolate. Some of these firms produce only for their own private lines, while others sell to chocolatiers who lack the facilities and ability to make their couverture in-house.
Several characteristics distinguish couverture chocolate. The first is the quality. Companies which manufacture this specialized chocolate use chocolate scouts who scour the world for the best cacao beans, and researchers work to refine the perfect bean blend to ensure a very specific flavor profile. Huge chocolate companies like Hershey and Mars actually invest substantially in the cacao industry to breed specialized beans to meet their needs, while smaller chocolate companies seek out exotic and interesting crops to make their chocolate unique.
The beans used in couverture chocolate are ground especially finely for an extremely smooth and uniform flavor, and additional cocoa butter is added to make the chocolate richer and creamier. The higher cocoa butter content also means that couverture chocolate has a distinct glossy appearance, a very crisp snap when broken, and the ability to be melted and tempered with ease. Couverture chocolate's unique properties make it ideal for chocolate fountains, with the cocoa butter acting as a lubricant to keep the chocolate from gumming up the fountain.
Chocolatiers use couverture chocolate to come up with their own chocolate formulations, and they also use it to cover truffles, mold chocolate garnishes, coat fruit, and perform a variety of other tasks. Couverture chocolate is generally not mixed in with an excess of other ingredients, because of the high price and quality; it is designed to stand alone as an ingredient. It can also be used to prepare chocolate shells, glossy coatings for cakes, and so forth.
Although couverture chocolate is used to cover chocolates and other sweets, it should not be confused with covering or coating chocolate, an inferior product which has much less cocoa butter. It is also not the same thing as baking or cooking chocolate. When seeking out couverture chocolate for cooking projects, your best source is probably a store or company which supplies wholesale products to bakers and cooks. You can also source couverture directly through some chocolate companies; you may want to order samples from several companies to seek out the flavor profile you prefer, as couverture can taste radically different depending on the source of the beans and how it is handled.