The High-Risk Distinction: Soft vs. Hard Cheeses
When evaluating the risk level of cheese, the primary factors are moisture content and pasteurization. Soft cheeses, like Brie, Camembert, and feta, are considered higher risk because their high moisture and low acidity create a favorable environment for bacteria such as Listeria monocytogenes. Listeria is particularly concerning because it can grow even at refrigerated temperatures, posing a serious threat to vulnerable populations.
In contrast, hard cheeses such as cheddar, Swiss, and Parmesan are generally considered lower risk. Their low moisture content and longer aging process create a hostile environment for bacterial growth. This does not mean they are immune to contamination, but the risk is substantially lower than with soft, fresh cheeses.
Pasteurization: A Crucial Safety Step
Pasteurization is a heat-treating process that kills harmful bacteria in milk and dairy products, significantly reducing the risk of foodborne illness. In many countries, the majority of cheeses sold in grocery stores are made from pasteurized milk. Always check the product label for the word "pasteurized" to ensure safety, especially when purchasing soft cheeses.
However, it is important to remember that pasteurization does not eliminate all risks. Cross-contamination can occur after pasteurization if the cheese is not handled or stored properly. This is why even cheeses made from pasteurized milk can sometimes be involved in food safety incidents, highlighting the need for vigilance throughout the food production chain and in the consumer's home.
The Exception for Aged Cheeses
Some unpasteurized cheeses are considered safe because they are aged for at least 60 days, a process that kills off potential pathogens. Hard, unpasteurized cheeses like aged cheddar or Parmesan are examples where the risk is minimal due to the hostile environment for bacteria. However, aged, unpasteurized soft cheeses still carry a greater risk.
Special Considerations for Vulnerable Groups
For most healthy individuals, the risk of getting sick from a properly stored, pasteurized cheese is very low. However, certain groups are at a much higher risk of serious complications from foodborne illnesses like listeriosis. These vulnerable populations include:
- Pregnant women: Are approximately 10 times more likely to contract listeriosis, which can cause miscarriage, stillbirth, or severe illness in newborns.
- The elderly: Have weakened immune systems that make them more susceptible to severe infection.
- Infants and young children: Have developing immune systems that are more vulnerable to bacteria.
- Immunocompromised individuals: People with conditions like AIDS, cancer, or diabetes are at increased risk.
Individuals in these high-risk groups should avoid all soft cheeses, even if pasteurized, unless they are cooked until steaming hot. Cheeses to avoid include Brie, Camembert, blue cheeses, and some Mexican-style cheeses like queso fresco.
How to Safely Store and Handle Cheese
Proper storage and handling can significantly reduce food safety risks. Follow these best practices:
- Use proper wrapping: Store cheese by wrapping it in cheese paper or parchment paper, followed by a loose layer of plastic wrap to allow it to breathe while retaining moisture. Do not wrap directly in plastic for extended periods.
- Refrigerate correctly: Store cheese in the vegetable crisper drawer of your refrigerator, as this area maintains a more consistent temperature and humidity.
- Avoid cross-contamination: Use separate utensils for different types of cheese to prevent transferring bacteria or mold. Store stronger-smelling cheeses away from milder ones.
- Handle mold appropriately: If mold appears on hard cheese, simply cut at least an inch around the affected area, and the rest is safe to eat. However, if mold appears on soft, shredded, or crumbled cheese, you must discard the entire product.
Cooking Cheeses for Added Safety
For those who love soft cheeses but are in a high-risk group, cooking them until they are steaming hot is a safe way to enjoy them. Heat kills harmful bacteria, including Listeria. Baked Brie, for example, is a safer option than eating it cold. This cooking method applies to any cheese where pasteurization is uncertain or for cheeses you would normally avoid. Cooking cheese into dishes like casseroles or enchiladas is another excellent way to ensure its safety.
Comparison of Safe vs. Risky Cheeses
| Cheese Type | Examples | Pasteurization | Relative Risk | Best Practice for Vulnerable Groups |
|---|---|---|---|---|
| Hard Cheese | Cheddar, Parmesan, Swiss | Often Pasteurized, sometimes Raw but aged | Very Low | Generally safe, avoid rind. |
| Semi-Hard Cheese | Edam, Gouda | Usually Pasteurized | Low | Generally safe. |
| Soft Pasteurized | Cream Cheese, Cottage Cheese | Always Pasteurized | Low to Medium | Safe, but some experts recommend caution with mould-ripened types. |
| Soft, Mold-Ripened | Brie, Camembert | Can be Pasteurized or Unpasteurized | Medium to High | Avoid unless cooked until steaming hot. |
| Blue-Veined | Roquefort, Gorgonzola | Can be Pasteurized or Unpasteurized | Medium to High | Avoid unless cooked until steaming hot. |
| Soft Unpasteurized | Queso Fresco, Raw Feta | Unpasteurized | High | Avoid entirely unless cooked until steaming hot. |
Conclusion
Is cheese a high risk food? The answer is not a simple yes or no. For the general healthy population, hard and pasteurized cheeses are safe and can be part of a healthy diet, providing valuable protein and calcium. However, specific types of cheese, particularly soft, unpasteurized varieties, present a higher risk of foodborne illness, especially for vulnerable individuals. By paying attention to pasteurization labels, practicing good food hygiene, and cooking potentially risky cheeses, consumers can safely enjoy dairy products while minimizing the threat of harmful bacteria. Always check with a healthcare provider if you have specific dietary concerns, especially if you are in a high-risk category. For more comprehensive food safety guidance, consult resources from authoritative organizations like the Centers for Disease Control and Prevention.
