Mold On Sour Cream: Safe To Eat? And How To Tell If It Is Bad

Sour cream is a popular dairy product used across the world as an ingredient and as the base for many dips and sauces.

So, what happens when you take your sour cream out of the refrigerator to make your favorite dip, only to find it has begun to grow mold? Can it still be eaten, what kinds of mold are growing, are they dangerous 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 growing on sour cream, keep reading.

Moldy sour cream

Related articles
Mold In Yogurt: Is It Safe To Eat And How To Prevent It
Does Milk Get Moldy And Is It Safe To Drink?
Moldy Butter: Is It Safe To Use And Can It Be Saved?
Mold On Ice Cream: Safe To Eat? And How To Tell If It’s Bad

Why does sour cream grow mold?

Sour cream grows mold easily because of its high water content and readily available nutrients that it can feed off.

Mold can contaminate the cream at many stages from the point it is produced to when you go to use it. For example, airborne mold spores can find their way into the tanks the milk is stored in before it is turned into sour cream, and whilst the pasteurization process will kill many strains of mold and bacteria, some have the ability to survive intense heat, and so remain in the liquid milk.

It can also find its way into the product during the storage and packaging processes due to either poor storage conditions or cross-contamination.

The environment that milk is stored in is an important factor when discussing the possibility of mold growth. Should the temperature the milk or cream is stored in reach higher than 40 degrees Fahrenheit for any amount of time, mold will be able to grow at a rapid pace.

What types of mold grow in sour cream?

The two most common strains of mold found growing in and on dairy products such as sour cream are penicillium and Mucor genera.

Penicillium strains are most commonly found growing within the soil, decaying vegetation, dry cereals, and fresh fruit and vegetables. It is usually through cross-contamination that it finds its way into dairy produce.

Mucor genera grow in similar circumstances to penicillium strains, but, most noticeably, it can commonly be found in soil and animal dung, so again cross-contamination is the most likely cause of Mucor strains being found in dairy.

Are the molds found growing in sour cream dangerous?

Yes, both penicillium and Mucor strains have the ability to produce unpleasant symptoms in people with allergic asthma and suppressed immune systems. In large doses, even otherwise healthy individuals can suffer from exposure to mold and its spores, these symptoms can include:

  • Nausea
  • Gastrointestinal discomfort
  • Vomiting
  • Diarrhea
  • Breathlessness
  • Skin irritation

It is important to note that in the majority of cases, many people would suffer from very little issue after coming into contact with either of these strains.

If you were to suddenly find yourself suffering from any of the symptoms listed above or any other new symptom, you should seek medical advice.

What does moldy sour cream look like?

Mold begins to grow on sour cream once it starts becoming rancid, the telltale signs of sour cream rancidity are a sour smell and taste, yellowing of the product, and visible signs of mold growth, usually appearing in patches with a green-blue to dark olive-gray coloration and a powder-like texture.

Visible mold growth takes several days to appear, starting with small circular patches that quickly spread over the remaining product, so as soon as you begin to notice any distinct change in smell and/or taste in the product, it should be discarded, as it is already past the point of saving.

What are the black spots on sour cream?

Black spots on sour cream indicate that the product has begun to turn rancid and grow mold. Small black, green, or blue dots found on the surface of the sour cream are often the first sign of mold growth.

Several bacteria (such as E. coli ), can begin to grow on expired sour cream at the same time as when mold begins to become visible, which can cause unpleasant symptoms if ingested.

It is for these reasons that if you notice any discoloration or small black, green, blue, orange, or white dots appearing on your sour cream, it should be discarded.

How long does it take for sour cream to grow mold?

Under the correct circumstances, mold can grow on any product extremely quickly.

For example, if you were to take an open pot of sour cream out of the refrigerator on a warm day and leave it to sit on the counter, mold, and bacteria can begin to grow within only a few hours.

The mold will not be visible to the naked eye at this stage and may take several days to form patches on the surface, but as long as there is a good amount of moisture and nutrients within a food item (with sour cream certainly has), it is the perfect place for mold to settle and create a colony.

What happens if you accidentally eat moldy sour cream?

The good news is that as long as you are a healthy individual without asthma or a suppressed immune system, and you were to accidentally eat mold that had been growing in sour cream, you would be unlikely to suffer any major symptoms.

As mold usually begins to grow in sour cream and dairy products that have already begun to spoil and become rancid, you would almost certainly be very aware that the product was not fit for consumption by either its taste or smell, so it would make accidentally ingesting a large enough quantity of mold to cause an issue by accident, unlikely.

However, if for any reason you did somehow manage to eat a large enough amount of rancid sour cream, both mold and bacteria could cause the following symptoms:

  • Nausea
  • Vomiting
  • Stomach cramps
  • Diarrhea
  • Allergic reactions

These symptoms can become serious if they persist for more than a few days, so if you become concerned by them, it is best to speak to a medical professional.

How to prevent sour cream from going moldy

Ensuring you are storing your sour cream correctly is the number one way that you can prevent mold and bacteria growth.

Once opened, keep the product in an airtight container in the refrigerator, preferably towards the back of the fridge and on the bottom shelves.

These areas of a fridge have the lowest humidity levels as well as more consistent temperature ranges, so will prevent fluctuations in the temperature of the product.

One other method that is frequently mentioned as being an effective method of prolonging the life of sour cream, is to store the product upside down in a sealed container.

The idea behind this is that because the lid is now on what is essentially the bottom of the container, the cream will seal any gaps where air could potentially find its what into the container.

By restricting airflow, the potential for bacterial and mold growth is lessened considerably.

Can moldy sour cream be saved?

Sour cream with mold found growing on it should be discarded as it is no longer fit for consumption.

Mold and bacteria growth speeds up considerably once dairy products have become rancid and will be far more likely to cause unpleasant symptoms in anyone who has consumed the product.

The taste, smell, and texture of sour cream will be noticeably affected once it has become rancid, and there is nothing that can be done to reverse this process once it has begun.

It is, therefore, best to discard any dairy product you suspect has become rancid, as it cannot be utilized in any safe way.

Can you scrape off the moldy parts from the sour cream and eat the rest?

No, scraping off the top layer of sour cream in an attempt to salvage what remains is not advised, as whilst you may have removed the visible mold, there are often “threads” (root-like structures) left within the deeper layers of yogurt.

If the strain of mold that was growing on your sour cream had produced mycotoxins or worse, aflatoxins, then these would also be present within the remaining yogurt and could cause symptoms if ingested.


Sour cream like many other dairy products will grow mold quickly under the correct circumstances. Penicillium and Mucor genera strains that commonly grow on dairy products can cause health complaints and allergic reactions in those with suppressed immune systems and allergies. Storing your sour cream in the refrigerator towards the bottom and back furthest from the door will improve its shelf life and prevent premature mold growth.

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.

Recent Posts