Can you get sick from eating bad cheese? (3 ways)

In this article, we are going to answer the question “Can you get sick from eating bad cheese?” and discuss what are the risks of eating bad cheese, how can cheese go bad, and how to know if cheese has gone bad.

Can you get sick from eating bad cheese?

Yes, you can get sick from eating bad cheese, especially when the cause of spoilage of cheese is the contamination by pathogenic bacteria (1, 2). 

Although the risks of spoilage are higher in cheese types made with unpasteurised milk and unripened cheeses (1), many food outbreaks have been reported involving cheese produced with pasteurised and even hard-ripened cheeses (1).

The most important causes of spoilage are insufficient pasteurisation of the milk and poor storage or handling practices. Cheeses commonly associated with food outbreaks are camembert cheese, Mexican-style cheeses, Brie and homemade soft cheeses (2).

Another problem related to foodborne diseases caused by the ingestion of cheese is cheeses sold in sliced or shredded forms, which do not always have a “best-by” date or expiration date, thus being stored and consumed after too long storage.

In addition, cheese can go bad due to lipid oxidation, resulting in the generation of oxidative products, such as aldehydes, ketones and peroxides, which characterise off-flavours and off-odours in cheese products and can be toxic when ingested in great quantities (4).

What are the risks of eating bad cheese?

The risk of eating bad cheese is experiencing a foodborne disease. Foodborne diseases can cause symptoms such as diarrhoea, vomiting, abdominal pain and fever (3).

Listeria monocytogenes is a pathogenic bacteria that can contaminate cheese products and many other foods and can cause, in addition to the common symptoms related above, neck stiffness, arthralgias (joint pain) and lead to hospitalisations and even death, especially in the case of elderly individuals and pregnant women (1, 3).

The ingestion of compounds resulting from the oxidation of lipids in the cheese can have negative effects on health. Monaldehydes and other substances derived from degraded fatty acids and vitamins in the cheese are known to have mutagenic and carcinogenic effects (4).

They act as free radicals in the body, leading to oxidative and inflammatory processes. In the long term, these oxidative and inflammatory processes in the body can lead to the development of many diseases, such as diabetes, and damage to the heart and the brain (4).

How can cheese go bad?

The main possibilities for cheese to go bad are (1, 2, 3, 4):

  • Contamination with pathogens present in the unpasteurised milk, in the case of cheeses produced with raw milk, such as Brie, Camembert and Mexican-style cheese
  • Contamination with pathogens present in the pasteurised milk due to insufficient pasteurisation or incorrect refrigeration of the milk
  • Contamination with contaminated milk cultures used in the process
  • Cross-contamination occurred during the simultaneous handling of raw foods and cheese
  • Poor hygienic practices in the kitchen or cooking place, improper or absence of hand washing, cleaning of utensils, etc.
  • Incorrect storage of cheese, especially fresh cheese
  • Too long storage of cheese in incorrect conditions, such as exposure to high temperatures and oxygen, favouring lipid oxidation

How to know if cheese has gone bad? 

To know if cheese has gone bad, you should observe the sensory properties of the cheese and identify possible indications that the cheese has gone bad. The main signs are (3, 4, 5):

  • Generation of off-odours and off-flavours indicating lipid oxidation characterised as rancid, soapy, “tallowy” or having a bitter aftertaste.
  • An off-flavour characterised as metallic or adstringent is also a sign of oxidation, whereas a musty aroma may indicate spoilage by psychrotrophic bacteria. 
  • Off-odours such as yeasty, pungent, sharp, suggestive of vinegar can be caused by the action of psychrotrophic bacteria in the cheese,
  • Discolouration (light-purple pigments, orange-coloured) or formation of slime on the surface can indicate microbial growth.
  • Formation of gas or blowing may be a sign of the action of anaerobic fermentation by bacteria of the Clostridium species. 
  • Unusual mould growth is characterised by dark green spots, brown spots and black spots.

Other FAQs about Cheese that you may be interested in.

Is cream cheese cheese?

Is cheese acidic or basic?

What is hard cheese?

Does shredded cheese go bad?


In this article, we answered the question “Can you get sick from eating bad cheese?” and discussed the risks of eating bad cheese, the ways cheese can go bad and how to know if cheese has gone bad.

Was this helpful?

Thanks for your feedback!



Yde M, Naranjo M, Mattheus W, Stragier P, Pochet B, Beulens K, De Schrijver K, Van den Branden D, Laisnez V, Flipse W, Leclercq A. Usefulness of the European Epidemic Intelligence Information System in the management of an outbreak of listeriosis, Belgium, 2011. Eurosurveillance. 2012 Sep 20;17(38):20279.


Robertson GL, editor. Food packaging and shelf life: a practical guide. CRC Press; 2009 Dec 21.


Lorenzo JM, Munekata PE, Dominguez R, Pateiro M, Saraiva JA, Franco D. Main groups of microorganisms of relevance for food safety and stability: General aspects and overall description. InInnovative technologies for food preservation 2018 Jan 1 (pp. 53-107). Academic Press.


DEMİRKAYA AK, ŞAHİN NG. Lipid Peroxidation Risk in White and Kashar Cheese. Atatürk Üniversitesi Veteriner Bilimleri Dergisi. 2021 Apr 4;16(1):73-9.


Clark S, Costello M, Drake M, Bodyfelt F, editors. The sensory evaluation of dairy products. Springer Science & Business Media; 2009 Jul 30.