Mold On Chips: Can They Get Moldy & Cause Throat Mold?

Chips (or crisps in the U.K.) are one of the most commonly eaten snacks in the world. They have a long shelf-life and are the perfect addition to parties and snacks to eat whilst watching films or sporting events.

So, what do you do when you open the packet and find that your favorite chips have got mold growing on them? Why did this happen in the first place, can you still eat them and how can you stop this from happening again?

In this article, we answer all these questions and more, so, for all you need to know about mold on chips, keep reading.

mold on chips

What causes mold on chips?

Mold grows on chips for the same reason it grows on other foods, the environment was correct for it.

Despite fungi (of which mold is a form of), being a complex organism, its needs are relatively basic and not too dissimilar to our own. All it needs are a source of hydration, nutrients, a small amount of oxygen, and preferably a temperature range between 60-80 degrees Fahrenheit.

Now that we know its requirements, let’s dive in a little deeper to see how you may be inadvertently providing what it needs.


Whilst fungi certainly need water to stay hydrated, they don’t need a great deal of it. In fact, humidity levels over 55% are great enough for the moisture in the air to begin condensing on cooler surfaces and forming droplets of water that fungi can use as a source of hydration.

Many elements within a home can cause large amounts of humidity, and certain rooms such as kitchens and bathrooms are the main offenders, as steam created from cooking and bathing passes through the property, raising its overall humidity levels.

Many states in the US also have year-round high-humidity levels, and when you add factors such as steam creation within a property, you are giving fungi all the humidity and moisture they could need.

Simply storing your chips in one of the high-humidity areas of your home could be a key component to why they are growing moldy faster than they should.


As we are discussing mold growth on potato chips, the nutrients part of the equation is fairly simple. When spores settle on a surface, they rapidly spread to form a colony, and this colony then feeds on whatever nutrients are available by releasing enzymes that break down the food source, allowing it to be absorbed.

Potato chips have all the minerals, fats, proteins, and carbohydrates that fungi need, making them a perfect source of nutrition.


Temperature is not a requirement for mold to “live” as such, as it can grow in cool temperatures and some strains have the ability to grow in temperatures nearing 100 Fahrenheit. However, the temperature range where it grows at its most rapid rate is between 60-80 degrees Fahrenheit. Many homes in the states set their central heating thermostats to between 70-75 degrees, and so for many months of the year, the ideal temperature range for its growth is provided.

What about tortilla chips?

Due to the way that tortilla chips are prepared, their shelf-life is considerably longer than many other food items, however, they are not immune to becoming moldy as some people may believe.

Tortilla chips are made from corn instead of potato, and still contain all the same nutrients found on potato, just in different amounts.

These amounts are still perfectly adequate for fungi to feed off, and if they are kept in the same conditions as potato chips, will be just as likely to suffer from fungal growth.

What types grow?

There are many strains of fungi that can grow on food and several are found very commonly. The most common strains to grow on potato chips include Penicillium, Aspergillus, and Cladosporium, with slightly less common strains including Alternaria and Rhizopus spp.

Some of these strains are more toxic than others as they have the ability to produce mycotoxins which can be especially harmful if ingested. Toxic strains that can be found growing on potato chips include Aspergillus, Penicillium, and Alternaria.

Without proper testing it can be very difficult to determine which strain may be growing on your potato chips, however, even strains that do not produce mycotoxins can be harmful to those with allergies so it is not advised to consume chips you believe to have mold growth.

Black mold on chips

For many years people have been under the impression that finding dark spots or patches of black dots on their potato chips indicated growth of fungi. This is usually not the case, and the fear that it could be something called “throat mold” has been debunked.

What you are more than likely looking at, is in fact starch in the potato that has oxidized after being exposed to air in a process known as enzymatic browning.

As long as the dark spots do not have a fuzzy texture and there is no musty scent, you can be confident you are not eating anything mold-related.

On tortilla chips, it is not uncommon at all to spot many small black dots on the chip’s surface. This again is not mold growth, but it is a result of specs of hilum scaring. The hilum is the part of the corn kernel that attaches to the cob whilst it is growing. After being picked from the cob, the hilum turns darker, eventually becoming black.

As the process of making tortilla chips involves grinding kernels into a paste, many of the blackened hila are left and can be seen within the finished tortilla chip, and are perfectly safe to consume.

Caramelization of proteins and sugars found in potatoes and corn can also turn black when exposed to high heat, resulting in the occurrence of black spots. This process is sometimes referred to as the Maillard reaction.

What do moldy chips look like?

Some of the telltale signs of mold growth on chips include discoloration, a fuzzy or powdery texture, and visible patches of colonies.

As the fungi can grow on any of the chips in a bag, it can be difficult to spot signs of growth initially, especially if it has only been growing for a short period.

What may be more obvious, is a strong musty odor when you open the packet. This smell indicates the growth of fungi and is sometimes compared to old socks or the type of musty smell you may find in a basement or attic.

Are the strains dangerous?

Yes, any form of mold has the potential to be hazardous to the health of humans and animals. Strains that produce mycotoxins such as Alternaria, Aspergillus, and Penicillium are particularly harmful when ingested and can lead to a number of serious symptoms.

Even strains that do not produce these toxins can cause unpleasant allergic reactions in those sensitive to them or people with suppressed immune systems.

Symptoms of mold spore inhalation or ingestion can include:

  • Coughing
  • Sneezing
  • Fever
  • Nausea
  • Vomiting
  • Diarrhea

What happens if you eat moldy chips?

If you accidentally eat chips you believe may have had fungal growth on them, in the majority of cases you will not need to seek medical advice unless you present with symptoms shortly after.

Many individuals would suffer from little if any symptoms, but in case you start to notice symptoms within 24-48 hours of consuming the food item, you should consult a physician.

If you are aware of an allergy that you have to mold, you should seek medical advice immediately.

How long does it take for chips to grow mold?

The amount of time that it takes for mold to grow on chips or any other food items is determined by environmental factors such as the humidity levels, nutrients within the food, and temperature.

If the bag of potato chips is in a vacuum-sealed bag, the time it will take them to grow moldy will be significantly higher. However, any imperfections within the packaging would expose them to moisture which would significantly increase the rate of growth potential.

Under the right conditions, mold can begin to grow on food products within just a few hours, and within several days, noticeable patches of growth would be able to be seen with the naked eye. However, the salt that is added to many flavors of chips acts as a preservative, as can many other ingredients aimed at increasing their shelf-life. It is for these reasons that it can take several days to even weeks before any noticeable growth would appear.

Does one moldy chip spoil the whole bag?

A common question asked when dealing with fungal growth on foods, is if one item in a bag is found to be moldy, does it spoil the rest of the items or can it be thrown out and the rest consumed?

Unfortunately, it is never advisable to consume products you feel may have come into contact with mold. Just because the remaining items appear to be free of growth, does not mean that spores have not been released and settled on other items in the packaging.

Should you have any allergies, consuming these spores could still cause allergic reactions and unpleasant symptoms.

How to prevent mold from growing on chips

The best way to prevent mold growth on chips is to remove all the requirements fungi need to grow, which includes storing them in areas of the property with the lowest humidity levels (away from kitchens and bathrooms), inspecting the packaging for any imperfections or tears, and consuming them promptly before the expiration date.

If storing leftover chips, ensure they are kept in an airtight container and put in a dry location, preferably with a source of natural sunlight as this will help to inhibit growth.


Mold certainly can grow on chips, and this is mostly caused by them coming into contact with high amounts of moisture, either from the humidity levels of the rooms they are kept in or otherwise poor storage conditions. The best way to prevent fungal growth on chips is to keep them as dry as possible, consume them within their expiration date, and if storing leftovers, keep them in an airtight container.

Chris Walker

Chris Walker has struggled for several years with mold after buying his own property. After finding the solutions to several issues around his home, he decided to create this site in order to answer as many questions about mold and mildew as possible to help others dealing with the same problems.

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