Question: What is the white film on solid chocolate?
Answer: That white or gray film or powdery coating that you sometimes see on the surface of solid chocolate is actually called "chocolate bloom". The white material is the cocoa solids that have separated from the rest of the chocolate and "risen" to the top. It usually happens when chocolate is improperly stored in an area that is too warm or too humid. Though it is somewhat unappealing to look at, chocolate that has bloom on it will taste fine and can still be used.