Cheese can spoil, like any perishable food. When cheese spoils, it often harbors undesirable microorganisms or their byproducts, which can pose health risks if consumed. Understanding the signs of spoilage and the potential effects of eating spoiled cheese is important for food safety, helping consumers make informed decisions to protect their well-being.
Identifying Spoiled Cheese
Recognizing spoiled cheese involves observing sensory cues. Visual signs include unusual mold growth not characteristic of the cheese type. While some cheeses, like blue cheese or Brie, are intentionally made with specific molds, unwanted mold typically appears as fuzzy spots of various colors such as green, black, or even pink or red on cheeses not meant to have them. Discoloration of the cheese body itself, beyond normal aging changes, such as fading, darkening, or turning black or blue, also indicates spoilage.
The smell of cheese provides strong clues about its condition. Spoiled cheese often emits a pungent, sour, ammonia-like, or putrid odor, which is distinct from the pleasant, characteristic aroma of fresh cheese. An excessive ammonia smell, especially in aged or washed-rind cheeses, can signal spoilage due to bacterial breakdown of proteins. Examining the texture can also reveal spoilage; cheese that has gone bad may feel slimy, excessively soft, mushy, or crumbly, or it might appear separated.
Immediate Health Effects
Consuming spoiled cheese can lead to immediate health effects, primarily due to harmful bacteria or their toxins. The body often reacts to these contaminants, resulting in gastrointestinal symptoms. Common reactions include nausea, vomiting, diarrhea, and abdominal cramps. Symptoms can range from mild discomfort to more severe illness, depending on the type and quantity of harmful microorganisms ingested, as well as an individual’s overall health and immune system strength.
Bacteria such as E. coli, Listeria, Salmonella, and Staphylococcus aureus are frequently implicated in cheese contamination. These pathogens can produce toxins that irritate the digestive system, causing rapid symptom onset. In some cases, a fever may also develop, indicating a more systemic response to the infection. While mild cases might resolve on their own, vomiting or diarrhea can sometimes lead to dehydration.
When to Seek Medical Attention
While many foodborne illnesses from spoiled cheese may result in mild, self-limiting symptoms, certain indicators warrant prompt medical consultation, especially if symptoms are severe or persistent. These include high fever exceeding 101°F (38.3°C) or diarrhea lasting more than three days. Severe dehydration, with symptoms like decreased urination, excessive thirst, dry mouth, or dizziness when standing up, requires medical intervention.
Other concerning signs include bloody or black stools, green or yellow vomit, or prolonged and frequent vomiting that prevents keeping liquids down. Neurological symptoms, such as blurred vision, difficulty speaking, muscle weakness, or confusion, can indicate serious conditions like botulism, though this is rare. Individuals who are more vulnerable to severe illness, such as young children, pregnant women, the elderly, and those with compromised immune systems, should seek medical care promptly, as they are at higher risk for complications like kidney failure, meningitis, or sepsis.
Preventing Consumption of Spoiled Cheese
Proper handling and storage are important to avoid consuming spoiled cheese. Store cheese in the refrigerator, ideally between 35°F and 45°F (1.7°C to 7.2°C), to slow microbial growth. The vegetable crisper drawer is often suitable due to its stable temperature and humidity.
Wrap cheese properly to allow it to breathe while preventing excessive moisture loss and air exposure. Cheese paper, wax paper, or parchment paper wrapped loosely, sometimes followed by a sealed container, achieves this balance. Plastic wrap can be used for convenience, but it is recommended to only cover the cut surface, allowing the rind to breathe, and to change it frequently to prevent mold development.
Adhering to “best by” or “use by” dates on packaging helps gauge freshness, though shelf life varies significantly by cheese type. Hard cheeses generally last longer (several weeks to months after opening) compared to soft cheeses (typically about one week after opening). Cheeses should not be left at room temperature for extended periods; ideally, no longer than two hours. When visible mold appears on hard cheeses, it is safe to cut away at least one inch around and below the moldy area, as mold typically does not penetrate deeply into these types. However, for soft, shredded, crumbled, or sliced cheeses, any sign of mold means the entire product should be discarded, as spores can easily contaminate the whole item.