Why chocolate turns white: A safe mystery unravelled

Have you ever opened a bar of chocolate that you've stored at home for a long time and noticed a white coating on it? Many of us wonder what it means and whether such chocolate can still be consumed.

Although the first impression might lead us to conclude that the chocolate is spoiled, the truth is somewhat different. The white coating that appears on chocolate is the result of specific processes related to storage methods and temperature changes.

The white coating on the surface of chocolate is not a uniform phenomenon. We distinguish two main types of coating: fat bloom and sugar bloom. Fat bloom occurs when chocolate is stored in fluctuating temperature conditions. Under the influence of high temperature, the fat in the chocolate begins to melt. When it gets cooler, this fat turns into a white coating.

Sugar bloom is the result of changes in humidity levels. When chocolate is cooled, sugar crystals on its surface dissolve. Due to water vapour condensation, after cooling, a white sugar coating forms.

The white coating can affect the taste and quality of chocolate, although the chocolate itself remains safe to eat. Fat bloom may give the chocolate a greasier taste and reduce its visual appeal. On the other hand, sugar bloom makes the surface rough, which can affect texture and taste. Despite these changes, chocolate with a white coating is not harmful to health, although it may be less pleasant to consume.

To avoid the formation of a white coating on chocolate, it should be stored in appropriate conditions. The best place is one where the temperature is stable without significant fluctuations. Chocolate should be stored at room temperature, away from direct sunlight and moisture. Keeping chocolate in the fridge or freezer is generally not recommended, as it can lead to sugar bloom due to water vapour condensation.

The white coating on chocolate, while it may look a bit unappetising, poses no health risk.