Book 27, Question 71
Why does old chocolate get a white film?
A white, powdery film on chocolate is called bloom.
Fat bloom happens when heat changes make some cocoa butter melt and then form new crystals on the surface. Sugar bloom happens when moisture dissolves surface sugar, which dries as tiny crystals. Chocolate with bloom is safe to eat but looks pale and may feel gritty. Storing it in a cool, dry place helps prevent it.