Question: Is Chocolate Harmful to Eat when it has Turned White?
Answer: It is very common to open a chocolate bar or box of chocolates and find a powdery white film on the chocolate inside. What is this white film on the chocolate, and is it harmful?
The answer is, probably not. While many people believe what they are seeing is mold on the chocolate, what they are more likely witnessing is a condition called “bloom”. There are two types of bloom.
Sugar bloom is caused by moisture coming in contact with the chocolate. When you eat chocolate, that chocolate is typically sweetened with sugar. As we know from junior high school chemistry, sugar comes in crystalline form, although in the chocolate you eat, those sugar crystals are usually small enough that you can neither see them nor feel them with your tongue. When moisture comes in contact with the chocolate’s surface, those fine crystals of sugar are dissolved. However, when the moisture dried or evaporates, the sugar crystals precipitate out of the former solution onto the chocolate’s surface.
The other kind of bloom, fat bloom, is more complicated. It is often caused by a combination of different factors, among them improper storage conditions, changes in temperature, or chocolate that has been poorly tempered (or not tempered at all). Chocolate with fat bloom may have a soft or crumbly texture, and it will often have tan or grayish-white blotches on its surface.
Neither sugar bloom nor fat bloom are harmful to people. However, either condition will probably render the chocolate unpleasant to eat. Considering that you taste with your eyes first, most people will not want to consume chocolate that has turned white in this way. In addition, the texture of the chocolate may be adversely affected, so it will not have chocolate’s usual silky-smooth texture. Note, though, that even if the chocolate has turned white, it is still good for many cooking applications or to turn into a wonderful cup of hot chocolate.