Imagine you’ve been waiting all day for five minutes to yourself so you can sit down and tuck into a bar of your favorite chocolate. You peel back the wrapper, excitement mounting, tastebuds tingling… but alas! It’s all covered in weird white stuff! Why does chocolate sometimes go white like this, and – most importantly – is it still okay to eat? Chocolate lovers of the world, rejoice: we got you.

Why does chocolate go white?

That unsightly coating you sometimes find on chocolate is called a bloom, and there are two different types.

A “fat bloom” occurs when the crystal structure of triglyceride fats in cocoa butter changes, for example if it melts a bit when stored improperly. These fats can separate from the other ingredients in the chocolate and move toward the surface, appearing as white or gray patches. It looks a bit… fungal, we’ll grant you, but rest assured it isn’t mold. 

Another variation of a fat bloom is where the fat has migrated away from parts of the chocolate, which can then appear lighter in color. You might get both of these fat blooms on one piece of chocolate.

The other type of bloom is a “sugar bloom”, which is less common. This happens when sugar in the chocolate dissolves after exposure to condensation or moisture. When the moisture evaporates, sugar crystals are left behind on the chocolate’s surface.

As British chocolatiers Whitakers explain, both types of blooms can look pretty much the same. Any type of chocolate – milk, white, or dark – can experience bloom, but there are some factors that can make it more likely. For example, chocolates with high-fat fillings like nut pralines may be more susceptible to fat bloom.

Is “bloomed” chocolate safe to eat?

This is the million-dollar question, and the answer is – thankfully – yes. 

Fat or sugar bloom does not make the chocolate unsafe to eat, but it might make it less tasty. It can affect the flavor and texture, so you might not enjoy that bar you’ve been looking forward to quite as much as you thought you would. 

How can you avoid chocolate bloom?

Safe it may be, but nobody wants bloomed chocolate. Luckily, there are some steps you can take to avoid it. 

Some of this lies in the production of the chocolate itself, which for most people (except perhaps those planning to enter the Great British Baking Show) is beyond our direct control. Tempering is a vital process when manufacturing chocolate products. The chocolate is heated and cooled slowly and precisely to ensure that crystals of cocoa butter form correctly and distribute evenly in the final product. It’s how chocolate gets that oh-so-appealing glossy exterior, and correct tempering also helps it resist fat bloom.

But assuming you’re purchasing the chocolate rather than making it yourself, this should all have been taken care of. All you need to worry about is proper storage. According to the folks at Whitakers, chocolate should be kept at a temperature between 17 and 20°C (63-68°F), but the most important thing is consistency – fluctuating temperatures are often the cause of fat bloom. You should also keep your chocolate in dry conditions to avoid sugar bloom, ideally in an airtight container.

Now here’s a debate for you: to refrigerate, or not to refrigerate? People have strong opinions about this, but as far as preserving chocolate quality goes, there’s only one answer. As explained by Hotel Chocolat – and let’s face it, they probably know what they’re talking about – storing your chocolate in the fridge can make sugar bloom more likely.

That does beg the question of what to do in the summer months, and we’re afraid there’s no easy solution to that, except to look for a dark, shady cupboard somewhere. Or you could just eat all your chocolate before it has a chance to bloom. We’ll leave that decision up to you.

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.