When cocoa butter or chocolate cools and solidifies, there are a number of different crystal structures that the fat particles can form. Unfortunately for chocolate manufacturers only one of these types of crystal is stable and give the lovely shine and “snap” characteristic of good quality chocolate. If you’re making chocolates it’s important to use a process called “tempering” to make sure the chocolate forms the right type of crystals.
If you’ve ever come across chocolate that looked like it had a white-ish dust or mold growth on the outside, this is called chocolate “bloom.” It’s a sign that either it wasn’t tempered correctly in the beginning, has been exposed to high temperatures at some stage, or is getting old. Don’t be alarmed, it’s just cocoa butter in the wrong crystal structure. It won’t hurt you to eat it.
