Blooming Chocolates

There's nothing like opening a much-anticipated box of chocolates only to find discolored, slightly gray candy. When chocolate turns gray; one of two is the culprit: sugar bloom or fat bloom.

Chocolate bloom is a sign that chocolate has not been stored correctly. The most obvious type of bloom, is fat bloom. Fat bloom may form on any chocolate causing unappealing dull gray-white blotches or streaks. Fat bloom forms when chocolate is exposed to heat during storage, causing cocoa butter crystals to melt and then re-crystallize. Sugar bloom, leaves chocolate feeling rough, and occurs when the chocolate is stored in damp or humid conditions.

Chemists in Sweden and Canada have used environmental scanning electron microscopy–to explain how a seductive, shiny surface of a chocolate, can change into an unappetising dull gray in poorly stored boxes and bars. They find that chocolate surfaces are heterogenous–bloom crystals grow from specific points on the surface. With filled chocolates, the liquid-state fat from the filling migrates through the chocolate–accelerating bloom formation and eventually, making the chocolate very soft.

Store chocolate at cool room temperature in a dark place with good air circulation. Ideally, chocolate should be wrapped in foil and then in plastic and stored at a constant temperature of 65°F and 50% humidity. The refrigerator in not recommended although if your kitchen is hot and humid, it might be your only choice. But you should wrap it well to protect it from odors. Formed chocolate candies such as truffles and pralines may be frozen, and defrosted in the refrigerator before being brought to room temperature for serving.

Although it might look less appetizing than a luscious, rich chocolatey-brown piece of candy, chocolate that has suffered bloom is still okay to eat. You may find the texture of sugar-bloomed chocolate to be a somewhat grainy on the outside, but it should still taste good. To prevent this from happening to your chocolate, simply use proper storage methods.