Imagine that you pull an unopened bar of your favorite chocolate out of the pantry, eager to take a bite, only to discover a whitish film discoloring the surface of your treat. This is a common occurrence and brings up many questions. What is the white layer? Is the chocolate still safe to eat? Can I still bake with it?
The whitish layer is what is known as “chocolate bloom.” There are two types of chocolate bloom: fat bloom and sugar bloom. The chocolate bar in the photo above shows only a very slight bloom: the dusty areas of what should be a shiny milk chocolate bar are patches of cocoa butter. Chocolate bloom can also look quite dramatic and the whole bar will be discolored.
Fat bloom is by far the most common type of bloom. It is usually caused when the chocolate is exposed to high temperatures – such as being left in your car on a sunny day – and then allowed to re-set. A warm environment will cause the cocoa butter to melt and separate from the rest of the ingredients in your chocolate, then rise to the surface of the bar creating an off-white “bloom.” Fat bloom can also be the result of improperly tempered chocolate. The best way to avoid fat bloom is by storing your chocolates in a cool place, preferably one where the temperature is consistent.
The second type of bloom is sugar bloom. This can be seen in chocolates that have a speckled appearance, rather than an even layer of white on their surface. It is caused by an excess of moisture that actually causes the sugar in the chocolate to crystallize. This is less common than fat bloom and can usually be avoided by storing your chocolates in a cool, dry place.
Chocolate that has bloomed is still safe to eat and still safe to bake with. It may not have the “snap” and silky-smooth texture of well-tempered chocolate, but the flavor will be just fine. I prefer to bake with chocolate that has bloomed because once you melt it down, it returns to its original condition and texture and you will never be able to tell that your cake, cookies or brownies started with a bar of bloomed chocolate.