Orders placed before 1pm will be delivered within 1 -2 days. | Same-day Central London delivery available


By using meltchocolates.com you agree to our use of cookies for personalised content, according to Our Data Promise

What causes chocolate to bloom? (turn white)

September 21st, 2023

What causes chocolate to bloom?

Ever wondered why your chocolate bar is covered in mouldy like layer? Like the picture below…

pieces of chocolate with chocolate white stuff and bloom all over them

It’s all because of something called “chocolate bloom.” When your chocolate goes from warm to cold and back again, it can change its chemical structure.

This happens because the cocoa butter in the chocolate melts and separates from the rest of it, making it crystallize and look white on the surface.

In this blog, we’ll explain why this happens, what causes it, and whether it’s still okay to eat your chocolate when it looks like this. Let’s demystify the world of chocolate together!

Two different types of chocolate bloom

So now we know what causes chocolate to bloom, now to identify what type of bloom has occurred.

Fat Bloom: Fat bloom in chocolate is caused by the cocoa butter within it. When the cocoa butter melts and then re-solidifies, it can create a dull white coating on the chocolate’s surface, making it lose its usual smoothness and shine. This undesirable effect is known as “fat bloom.”

chocolate bloom on a chocolate bar

Fat bloom typically happens for two main reasons. Firstly, it can occur due to incorrect tempering, which is the process of ensuring that the cocoa butter crystals are evenly distributed in the chocolate during its melting and solidifying stages. Secondly, fat bloom might happen if you store chocolate at too high a temperature, causing the cocoa butter to melt and rise to the surface.

So if you are leaving your chocolate in direct sunlight, in a warm cupboard or even leaving it in your car, you may see chocolate bloom appearing.

To prevent fat bloom, choose a cool, dark cupboard away from strong odours to store your chocolate goods.

Sugar Bloom: Chocolate afflicted with sugar bloom often develops a rough, whitish surface and a grainy texture. This type of bloom is usually the result of temperature changes or storing chocolate in a humid environment.

Temperature shock plays a significant role in sugar bloom. It occurs when you quickly shift chocolate from a warm or hot location (like an open shelf near the oven) to a cold one, such as the fridge. This abrupt change in temperature causes condensation to form on the chocolate’s surface, which then interacts with the sugar in the chocolate, leading to sugar bloom. For instance, if you place your chocolate molds in the fridge right after making them, you risk exposing them to temperature shock. To prevent sugar bloom, allow your chocolates to cool down at room temperature before refrigerating them.

Chocolate sugar bloom

Is bloomed chocolate safe to eat? 

Yes! Certainly, don’t let good chocolate go to waste. Especially when you were so excited to eat it. It will taste exactly the same, though may have a different texture.

If you don’t want to eat it directly, and the thought puts you off. There are many different ways you can use bloomed chocolate. For one, you can melt down the chocolate in some milk and make a delicious hot chocolate. Check out our 3 Luxury Hot Chocolate Recipes for some inspiration.

Or if a birthday is coming up, save up the chocolate in the cupboard and use it to make a delicious chocolate cake or brownies. Good chocolate can be expensive, so there is no point of wasting it when you can still enjoy it in many different ways.


In conclusion, the mystery of chocolate bloom has been unraveled! Whether it’s the fat bloom caused by cocoa butter or the sugar bloom brought about by temperature changes, we’ve delved into the secrets behind these transformations. Remember, even though bloomed chocolate may not look its best, it’s still perfectly safe to enjoy.

So, whether you’re a novice chocolatier or a chocolate aficionado, armed with this knowledge, you can savor your sweet creations with confidence. Just keep your chocolate cool, dry, and away from sudden temperature swings, and you’ll be on your way to a deliciously satisfying chocolate experience every time. Happy indulging!

Is the white stuff on chocolate mold?

No, it is most likely chocolate bloom, which occurs when the chocolate has undergone big temperature changes.

Is it OK to eat chocolate that has bloomed?

Yes, it is perfectly safe to eat bloomed chocolate! It may have a different texture, but should taste just as good.

What does sugar bloom look like on chocolate?

Sugar bloom looks like a pattern of white dustings on the first layer of your chocolate.

What are the two different types of chocolate bloom?

There is fat bloom and sugar bloom - both are caused by temperature changes.



Be the first to know about Melt’s new collections, promotions and events

By signing up you accept the terms of Melt’s Privacy Policy