Chocolate sugar bloom

Chocolatiers refer to this as a bloomed chocolate, which is a wonderfully obscure and appealing way of describing the white stuff that forms on old Halloween candy. There are two processes that could be happening here, either sugar bloom or fat bloom. 

Sugar bloom is the candy world s way of saying sugar crystallization. If your candy is exposed to moisture, sugar molecules dissolve out of the fat in the chocolate and once that moisture evaporates, the separated sugars have a chance to crystallize. 

Chocolate (Figure 2.20) consists of a continuous phase of cocoa butter, substantially crystalline at room temperature and comprising 30 to 35% of the whole, in which sugar and cocoa solids are suspended. Milk chocolate also contains milk fat and solids. Lipids in chocolate have great importance in bloom formation. Bloom is a defect in the surface appearance of chocolate that appears as a white, powdery deposit. It is known to be associated with changes in the polymorphic forms of cocoa butter. 

Up to six polymorphic forms of cocoa butter crystals have been reported. It is common practice to work chocolate into very stable P or small jS crystal forms by slow agitation, careful control of temperatures, and tempering (holding) freshly cast products under specific conditions before release to the trade. Bloom, a grayish defect, occurs when chocolate or other types of coating fats have been allowed to partially melt, and some oils rise above the sugar and coloring matter in the product and recrystallize. 

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