Why Does Chocolate Turn White? Unraveling the Sweet Mystery

By: HowStuffWorks.com Contributors & Desiree Bowie  | 
Chocolate truffles on a clean plate. One chocolate is slightly white on the outside.
The primary culprit of chocolate with a greasy or powdery white exterior? Poor storage. Kseniya Ovchinnikova / Getty Images

There's nothing quite like opening a much-anticipated box of chocolates only to find discolored candy with a white coating. Upon encountering this seemingly random anomaly, one question may come to mind: Why does chocolate turn white?

Luckily, the answer is pretty straightforward: This phenomenon is due to either sugar bloom or fat bloom, both of which can alter the appearance of your chocolate treats.


Understanding the science behind bloomed chocolate and learning how to prevent it is crucial for preserving the visual appeal of your sweets. In this article, we'll explore the causes of chocolate bloom and walk through how to store chocolate properly to prevent that unappetizing coating from forming.

What Causes Chocolate to Turn White?

Chocolate turns white due to a phenomenon called "chocolate bloom," which is the formation of white or grayish streaks or spots on the surface of the candy. There are two main types of bloom — sugar and fat — and they have different causes.

Sugar Bloom

Sugar bloom is normally caused by surface moisture. The moisture causes the sugar in the chocolate to melt. Once the moisture evaporates, larger sugar crystals form, creating a white, powdery coating on the surface of the chocolate.


This type of bloom can make the chocolate look dull and matte, and the texture may feel slightly gritty when touched. If this process is repeated, the surface can become sticky and even more discolored.

Sugar bloom is most often the result of overly humid storage, but it can happen when the chocolate has been stored at a relatively cool temperature and is then moved too quickly into much warmer surroundings. When this happens, the chocolate sweats, producing surface moisture.

Fat Bloom

On the other hand, fat bloom is caused by the crystallization of fats, typically cocoa butter, within the chocolate.

This reaction occurs when cocoa butter fats migrate to the surface due to temperature fluctuations, and these fats crystallize in an unstable form, resulting in a whitish or grayish appearance on the chocolate's surface and an altered texture. The chocolate may be slightly greasy when touched.


Is Bloomed Chocolate Safe to Eat?

Luckily for chocolate lovers, sugar and fat bloom are cosmetic issues rather than signs of spoilage. Although it might look a little less appetizing than a lustrous, rich chocolatey-brown piece of candy, bloomed chocolate is still okay to eat.

However, you may find the texture of sugar-bloomed chocolate to be a bit grainy on the outside, but it should still taste good. To prevent this from happening to your chocolate, simply use proper storage methods. More on that later.


How to Fix Bloomed Chocolate

Retempering bloomed chocolate is a process that involves melting and then carefully cooling the chocolate to restore its proper crystalline structure and appearance. This method is especially effective for chocolate that has experienced fat bloom (when cocoa butter separates from the cocoa solids).

Here's what you'll need:


Now you're ready to retemper that chocolate:

1. Chop the Chocolate

Begin by chopping the bloomed chocolate into small, even-sized pieces. This helps it melt evenly and facilitates the tempering process.

2. Melt the Chocolate

If using a microwave, place the chopped chocolate in a microwave-safe bowl. Microwave in short, 15- to 20-second bursts at a medium-low power setting (50 percent power) to avoid overheating. Stir between each burst. Continue microwaving and stirring until the chocolate is almost fully melted.

If using a double boiler, fill a pot with water and bring it to a simmer. Place the chopped chocolate in a heatproof bowl and set it over the simmering water, making sure the bowl doesn't touch the water. Stir the chocolate gently until it melts completely.

3. Check the Temperature

Use a food thermometer to monitor the temperature of the melted chocolate. The temperature varies depending on the type of chocolate.

  • Dark chocolate: Aim for 88–90 degrees Fahrenheit (31–32 degrees Celsius).
  • Milk chocolate: Aim for 86–88 degrees Fahrenheit (30–31 degrees Celsius).
  • White chocolate: Aim for 82–84 degrees Fahrenheit (28–29 degrees Celsius).

4. Seed the Chocolate

To encourage the proper crystallization of cocoa butter, add a small amount (about 10–20 percent) of unmelted chocolate pieces to the melted chocolate. Stir continuously until these pieces melt and the mixture reaches the target temperature.

Once you've reached the correct temperature, remove any remaining unmelted chocolate pieces from the mixture.

5. Cool and Test the Temper

Continue stirring the chocolate gently until it becomes smooth and glossy, which indicates that it has been properly tempered. To verify that the chocolate is properly tempered, dip a knife or spatula into the chocolate and let it cool at room temperature. It should harden with a glossy finish.

You can now use the tempered chocolate as needed in your recipe or for dipping and molding. If you're not using it immediately, keep it in a dry airtight container.


Can You Fix Sugar Bloom?

Sugar bloom is typically irreversible once it occurs because it involves the recrystallization of sugar on the chocolate's surface due to moisture exposure. However, you can still try to improve the appearance of the chocolate by gently brushing off the loose sugar crystals with a dry, soft brush or a clean cloth.

Keep in mind that this won't completely restore the chocolate to its original texture, but it can make it more visually appealing. To prevent sugar bloom in the first place, store chocolate in a cool, dry place, away from moisture and temperature fluctuations.


How to Avoid Chocolate Bloom

The best way to avoid chocolate bloom is to store the candy properly. Since the treat can easily absorb flavors from food or other products situated nearby, chocolate should be tightly wrapped and stored away from pungent odors.

The ideal temperature for storage is somewhere between 65 and 68 degrees Fahrenheit (18 and 20 degrees Celsius), with no more than 50–55 percent relative humidity. If stored properly, you can expect milk chocolate and white chocolate to be good for up to six months.


Dark chocolate with a high cocoa content, typically around 70 percent cocoa or higher, tends to have a longer shelf life than other types of chocolate. Due to its lower sugar content and higher levels of cocoa butter, dark chocolate is less susceptible to sugar and fat bloom and can last up to a year if stored in ideal conditions.

This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.

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Chocolate Expiry FAQs

What does it mean when chocolate turns white?
Discoloration of chocolate happens for two reasons: fat bloom or sugar bloom. Fat bloom occurs when liquid fat moves through the chocolate and then crystalizes on the surface. It's usually caused by a quick change in temperature. Sugar bloom occurs when the chocolate gets a bit wet, and the moisture draws out the sugar. When it dries, it leaves the whitish crystals behind. Both are harmless. The texture just might be a bit grainy.
How long can chocolate last?
When stored properly in a dry and cool place, milk chocolate and white chocolate can last for up to six months while dark chocolate with a high cocoa content can last for up to a year. Truffles and coconut topping chocolates, on the other hand, last only for three to four months.
How long can you eat chocolate after the expiration date?
If stored properly, you can eat milk chocolate and white chocolate two to four months after the expiration date without any difference in taste or quality. On the other hand, dark chocolate with a high cocoa content may last for up to one year.
Can chocolate be stored at room temperature?
You can store chocolate at room temperature without any major impact on the overall quality.