Can chocolate spoil? (3 Reasons it could)

In this brief guide, we will answer the question “Can chocolate spoil?” We will discuss the reasons which make chocolate spoil and discuss the shelf lives of some common chocolates as well.

Can chocolate spoil?

Yes, chocolate can spoil. Factors that can cause the quality of chocolate to decline can be fat bloom, sugar bloom, substandard ingredients, perishable ingredients, or improper storage and handling [1]. 

Whether or not chocolate is more prone to spoilage depends on the content of cacao in a bar, the moisture or milk content, and the presence of non-cacao ingredients.

Components such as cream, butter, nuts, caramels, raisins, wafers, and other wet fillings can contribute to chocolate spoilage.

These products can be a source of contamination, as well as they easily absorb moisture under inadequate storage conditions, favoring microbial development and quality loss [1].  

In general, the low moisture content of chocolate products makes them less perishable foods, with a shelf life of a few bonus years [1]. However, the span of chocolate also depends on how you handle and store it. 

Improper storage, processing, and packaging – for example, poor hygiene and moisture gain – may encourage microbial contamination and growth.

What does make chocolate spoil? 

Chocolate spoils if its ingredients go bad, or if it is stored or packed improperly. Raisins will dry out, and nuts become rancidity and gain moisture, as well as wafers.

According to reports in research, adequate storage humidity and temperature are key factors to protect chocolates from many quality-associated issues, such as sugar crystallization, melting, and fat bloom [1]. 

Last but not least, the package must serve as a barrier to water vapor permeability.  In the absence of an effective wrap for chocolate, products will tend to lose or soak up moisture. 

The buildup of moisture on the surface of chocolates could then lead to mold growth on products [1].

How long do some commonly eaten chocolates last?

Have a look at the table ahead for the shelf life of some chocolate products [1].

Chocolate typeTypical shelf life 
Dark chocolate24 months
Milk and white chocolate16
Chocolate-coated fondant18
Milk chocolate-coated peanuts
Chocolate bars with raisins
Chocolate-coated wafer
Chocolate shells with soft caramel center
Chocolate shells with praline center


As you can see, the presence of non-cacao ingredients shortens the shelf life of chocolate, which happens for several reasons. For instance, extra ingredients can be a source of contamination for chocolates. 

Furthermore, they can be more or less prone to chemical reactions due for example to nuts that may undergo fat oxidation; to moisture loss, due to raisins; or to moisture absorption, as is the case of chocolate-coated wafers [1].

How to know that chocolate has gone bad? 

Here are the main transformations taking place when dark chocolate goes bad. 

  • Fat bloom: visibly recognized as a whitish superficial layer on chocolate accompanied by loss of surface gloss, the fat bloom is nothing more than fat crystallization on the surface of the chocolate. 

Factors leading to fat bloom include storage at temperatures higher than 18°C, melting of chocolate followed by recrystallization, and inadequate processing conditions [2]. 

  • Sensory changes: chocolate is high in fat, so one sign that it has gone bad is rancidity caused by fat oxidation. Although dark chocolate is rich in antioxidants, over time, fat oxidation is inevitable.

Other sensory changes comprise stale favor, hardness, crumbliness, and loss of superficial gloss.

Chocolates incorporated with nuts may experience extra rancidity because nuts are usually rich in unsaturated fat. They can also lose texture due to moisture pickup.   

  • Sugar bloom: means the crystallization of sugars on the surface of the chocolate, and is caused by moisture absorption.

Any of these signs can harm your health, they are just quality markers.

Although microbial growth is unlikely, incorrect storage conditions may somehow promote it. Therefore, upon any manifestation of mold, which shows a cotton appearance on the surface of the chocolate, discard the chocolate immediately.

How to store chocolate?

  • Chocolates should be kept in a dark, cool, dry area. 

It’s OK to keep it in the cupboard or a kitchen cabinet; it doesn’t need to be refrigerated. After you’ve opened the bag, make sure it’s properly wrapped before putting it away.

Adequate stock conditions protect the chocolate from heat (which promotes melting, fat bloom, and fat oxidation); moisture (which causes texture loss and sugar crystallization; and light (which can favor fat oxidation).

  • The optimum shelf life is at temperatures of about 18 °C or less [1,2]. According to studies, in general, the lower the temperature, the lower the bloom risk [2]. 

if the temperature rises to 30°C, it isn’t a huge problem, but the chances to occur fat bloom are increased. 

Above this temperature, chocolate is partially melted, and upon recrystallization, the fat bloom is very likely to take place [2].  

  • Hold the bar far from any heat sources while storing it, since heat may melt the chocolate.
  • After you’ve opened the bar, cover the chocolate in the aluminum foil that came with it, or seal up the bag if it’s resealable.

Can I eat expired chocolate?

  • Unopened packs: chocolates usually come with a best-before date, which means that after the date printed on labels, the quality of the product is no longer guaranteed, but it is still safe, according to the US Department of Agriculture [3]. 

Therefore, if your chocolate is sealed, has been stored properly, and does not show any sign of spoilage, it is supposed to be safe because the low moisture content of chocolate makes it a hostile environment for microbial growth.  

However, the quality of the chocolate can have dropped significantly past the best-before date. For instance, you may find the chocolate stale, the nuts rancid, or the wafer soft.  

So the best thing to do is to analyze case to case before deciding whether to eat the chocolate or not.

  • Opened packs: if you find a forgotten slice of chocolate in your pantry that has been previously opened but not finished before the best-before date, I do not recommend eating it, even if it looks ok. 

Although chocolate is considered a stable product due to its low moisture content, Morasi and others [4] highlighted that pathogens like Salmonella ssp. can survive in adverse ambient of low-moisture foods, including chocolate.

The authors also drew attention to the contamination of chocolate ingredients, such as nuts, peanuts, and almonds, which could take pathogenic microorganisms to chocolates. 

In these products, the surviving bacteria will wait until favorable conditions come up, such as moisture increase due to water absorption from the surroundings, after which they will develop quickly. 

Therefore, it is not a good idea to eat chocolate that has been opened for a long time and expired, or that you obviously see has been badly stored, for instance, exposed to moisture or mild heat.

If contaminated, these conditions could encourage salmonella and other pathogens to grow. 


In this brief guide, we answered the question “Can chocolate spoil?” We discussed the reasons which make chocolate spoil and the shelf lives of some common chocolates.


1. Subramanian P. The Stability and Shelf Life of Confectionery Products.

2. Lonchampt P, Hartel RW. Fat bloom in chocolate and compound coatings. European Journal of Lipid Science and Technology. 2004;106(4):241-74.


4. Morasi RM, Rall VLM, Dantas STA, Alonso VPP, Silva NCC. Salmonella spp. in low water activity food: Occurrence, survival mechanisms, and thermoresistance. Journal of Food Science. 2022;87(6):231

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