How can you tell if chocolate has gone bad

15 Jul 2020

Chocolate Knowledge

We explore whether chocolate can go bad so that you can enjoy chocolate at its prime

There’s nothing worse than opening up a packet of chocolate you’ve been waiting to dive into before realising its past its best before date. We’ve explored how chocolate is made in a previous blog – but how do you know if your chocolate has past its prime? Whilst chocolate may have a longer shelf life compared to other foods, it can sometimes change in appearance and texture, leaving some to question whether their chocolate has gone bad.

Although there’s no such thing as mouldy chocolate, you might want to avoid your bar if you think there are signs that it’s seen better days. If you’re not sure what to look out for then don’t worry – we’ve broken down the different ways chocolate can go bad, and how to avoid this in the future.

Can chocolate go bad?

For most of us, a bar of chocolate won’t last longer than a few hours after purchase, let alone long enough for it to go off. However, if left for too long then you might start to notice some changes…

Quality and freshness

High quality chocolate is best eaten within a few months of purchasing. This is because luxury chocolate brands use fresh ingredients in their chocolate and no additives – at Hotel Chocolat we only use natural ingredients in our chocolates, and use nothing artificial, ever. By using real ingredients such as freeze-dried strawberries in our Eton Mess, we can capture all the fresh and authentic tastes of the real thing. 

White chocolate Hotel Chocolat Eton Mess Selector
Freeze dried raspberry and meringue makes our White Chocolate Eton Mess Selector authentic

Difference in scent

Good quality milk and dark chocolate should have a smell that is rich in cocoa, and even white should have a fragrant cocoa butter smell to it. However, if your chocolate has a savoury whiff to it then it might have been left for too long.

Cheaper chocolates which have additives in them will last a lot longer before going off. Dark chocolate also keeps very well: flavonols, an antioxidant found in cocoa, contain natural preservatives, which is why dark chocolate with a high cocoa percentage will keep better than a cheaper dark chocolate containing less than 70% cocoa solids.

We’ve upped the cocoa content in our dark to about as high as you can get with our 100% dark chocolate, so that you can make your chocolate last for as long as you want it to.


As cocoa butter absorbs flavours and odours, you could find yourself munching on a chocolate bar which tastes like last-night’s leftovers. Cold temperatures from storing your chocolate in the fridge also prevents your chocolate bar from releasing more subtle flavours, meaning you don’t quite get all the nuanced notes of cocoa.

Whilst this isn’t a sign that your food has gone off, it could show that you need to store your chocolate properly. As unwrapped chocolate absorbs odours when it is in close proximity with other foods, this can affect the overall taste of your chocolate bar. So, whilst it isn’t technically a sign that your food has gone bad, you also don’t want the aromas of chilli con carne or curry permeating through your chocolate.

Besides the scent which can alter the overall taste of your chocolate, an overpowering bitterness is also an indicator that your chocolate has gone bad.

If you’re not sure if your chocolate is OK to eat, have a little nibble on it – if you taste anything other than the mellow, satisfying notes of cocoa, then your chocolate might be ready for the bin.


This is the biggest giveaway as to whether your chocolate has passed its peak is if it blooms. If you see a white or grey hue to your chocolate then it’s probably had a fat bloom – whilst it takes away from the glossy shine of your chocolate, it doesn’t affect the taste.

If your chocolate has a grainy and bitty texture then it will have experienced a sugar bloom. This can happen when your chocolate has been exposed to humidity or quickly moved from cold to hot temperatures. Again, whilst this doesn’t affect the taste of your chocolate, it does make for an unpleasant texture. But why does this happen?

The science behind the bloom

The fat bloom is commonly caused by the liquid fat – found in cocoa butter – crystallising on the surface of the chocolate. The exact stage in which the crystallisation process occurs is more of a mystery.

Writing in Applied Materials & Interfaces, a leading Chemistry publisher, researchers found that adding sunflower oil to a powdered mixture of sugar, milk powder, cocoa and cocoa butter meant that the liquid fat moved quickly through pores and tiny spaces of the chocolate.

After a few hours, the oil had softened into the solid chocolate, leading to an increased migration of the fat, resulting in a stronger bloom. The researchers suggest that minimising the amount of fat that is liquid at room temperature in the chocolate. They added that keeping it at a cool temperature – around 18C – can help prevent the unattractive bloom.

Can out of date chocolate make you ill?

Whilst most chocolates can go bad in the sense it might taste or look a bit different to a fresh chocolate bar, eating an out of date chocolate bar wouldn’t have the same repercussions as eating a piece of mouldy fruit or a bit of old beef.

In fact, chocolate doesn’t even have an expiration date, only a best before date. The difference between these two are quite considerable: an expiration date is used for foods which are unsafe to eat after a certain period, whereas a best before date is typically the time given before the food passes its peak.

Generally, chocolate is safe to eat after its best before date, however, this depends on the exact ingredients of your chocolate, as well as your personal references. For example, if you’re eating a fresh-cream truffle then you’ll want to eat them as soon as possible, due to the short-shelf life of the cream – chocolates which use fresh ingredients tend to go off within a few days of purchasing.

The reason as to why chocolate doesn’t go off in the same way as a lot of other foods is because it doesn’t contain any water, which is what bacteria needs to thrive and grow. As bacteria can’t live in chocolate, chocolates don’t have a use by date. Even if a bloom does appear, or your chocolate has a peculiar smell to it, it will still be safe to consume.

Does this depend on the type of chocolate?

As mentioned above, dark chocolate naturally keeps well, due to the high flavanol levels within it. Because it doesn’t contain milk, dark chocolate is also more likely to keep the best.

The ingredients in the chocolate also plays a role in how long it will last until it passes its best before date: fruit and nuts in chocolate can go off quicker than the chocolate itself, so make sure you don’t leave these bars for too long.

Can putting your chocolate in the fridge stop it from going bad?

Some might think that storing your chocolate in the fridge is the best way to keep your chocolate fresh, but it can actually have the opposite effect. Although you might want to put your chocolate in the fridge to stop it from melting in the summer, or to make sure it lasts as long as possible, putting chocolate in the fridge can affect your chocolate in more ways that you may think.

How can you save your chocolate?

So far it seems that in the summer, chocolate fans are damned if they do, and damned if they don’t; the choice between melted, squishy chocolate or hard, granular chocolate doesn’t seem like an easy one.

However, there are ways to protect your chocolate from the heat of summer. Considering that, for best results, chocolate should be stored in a temperature between 10C-20C, look for any cooler, shady parts of the house to store it in: a basement would be a good option. However, if the whole house seems to be warming up and there doesn’t seem to be another option, you can store your chocolate in the fridge, although you need to take a few precautions to ensure the quality of your chocolate isn’t lost.

Store your chocolate in an airtight container to ensure any unsavoury flavours don’t permeate your chocolate, altering its taste. To ward off the dull flavour and a brittle texture that refrigerating chocolate results in, take your chocolate out of the fridge roughly 30 minutes before eating, although make sure you don’t leave it directly in the sunlight. This ensures your chocolate has time to warm up to the room temperature without becoming a melted mess.

Does this apply to all chocolate?

Although we’ve been warning you against storing your chocolate bars in the fridge, there are times when refrigerating chocolate is a necessity. This is if you want to get creative in the kitchen and use chocolate as a decoration for your baked goods. Whatever design you opt for, you’ll want to melt it down and refrigerate it on a sheet of baking parchment if the ambient temperature is higher than 30C – remember, in the summer, chocolate is much more likely to remain a liquid form at room temperature.

To keep the quality of your chocolate high, you’ll need to temper your chocolate to ensure that it doesn’t become dull and crumbly in the fridge. Whilst this might appear technical, tempering your chocolate is a relatively easy process, and it can be made easier by using chocolate which melts evenly and smoothly. We suggest using chocolate drops – their miniature size means your chocolate melts effortlessly.

Now you know the best way to store your chocolate in the summer, you’ll want to find the best type of chocolate to enjoy in warmer conditions. Whether you opt for fruity chocolates, or a chocolate which is for adults-only, treat yourself to chocolate, whatever the weather.

So, whilst chocolate is safe to eat even after it’s past its best before date, it might not be as delicious as if you ate it within a few days of buying it. At Hotel Chocolat, we use natural ingredients only, which is why our chocolates might not last as long as the others you see on shelf. However, we think this is a necessary sacrifice – natural always tastes better.