Chocolate Bloom: Why Chocolate Turns White and Whether It Is Safe

By the Chocolate Near You editors · September 8, 2026 · 5 min read

You unwrap a bar and find it streaked with grey, or covered in a dull white dust. It looks spoiled, but it almost certainly is not. That coating is called bloom, and it comes in two kinds.

Fat bloom

Fat bloom looks like soft grey or white streaks and swirls, and it can feel slightly greasy. It happens when cocoa butter crystals melt and reform in an unstable way, or migrate to the surface.

Common causes are temperature swings, storage that is too warm, chocolate that was not tempered properly, and filled chocolates where oils from a nut centre slowly work their way outward.

Sugar bloom

Sugar bloom is a dry, dusty or gritty white film. It is caused by moisture: water lands on the surface, dissolves some of the sugar, then evaporates and leaves sugar crystals behind. The classic trigger is taking chocolate out of the fridge into a warm room, where condensation forms on it.

How to tell them apart

Rub the surface gently with a fingertip. Fat bloom usually softens or smears because it is fat and melts at body temperature. Sugar bloom stays put and feels rough or powdery, and a drop of water on it will dissolve some of the crystals.

Is bloomed chocolate safe to eat?

Bloom on its own is a quality issue, not a safety issue, and bloomed chocolate is generally safe to eat. You lose the glossy look, the clean snap and some of the smooth melt. Use your judgement as with any food: if chocolate smells off, has fuzzy growth, or has passed its date, throw it away.

What to do with it

Melting resets the structure, so bloomed chocolate is perfect for baking, brownies, sauces, ganache and hot chocolate. Once melted and cooled, it will not regain its snap unless it is tempered again, but in a recipe nobody will notice.

How to prevent bloom

• Store chocolate somewhere cool and steady, roughly 60 to 68 degrees Fahrenheit.
• Avoid the fridge for bars. If you must chill chocolate, seal it and let it warm up inside its container before opening.
• Keep it away from heat sources and sunlight, including a warm car.
• Eat filled and nut-based chocolates sooner, since oil migration makes them more prone to fat bloom.

For the full rundown on temperatures and shelf life, see how to store chocolate.

Keep reading

• How to Store Chocolate So It Stays Fresh
• Cocoa Percentage Explained: Dark, Milk and White Chocolate
• How to Taste Chocolate Like a Chocolatier