Different

Types Of Cheese

And How To Tell When Mould Is Safe To Eat Or Time To Bin It

Quick Summary

Mould on cheese is not always dangerous: certain varieties are deliberately ripened with specific mould cultures. However, unexpected growth on soft, fresh, shredded or sliced cheese means discarding the product. Firm blocks such as cheddar may be salvageable by cutting away the mould and surrounding cheese correctly.

Deep Dive

Cheesemaking uses carefully selected moulds and bacteria to develop characteristic flavours, aromas and textures. Unwanted mould is different because its identity and spread are unknown. Moisture, density and processing affect how far contamination may travel beneath the surface. Knowing which varieties are intentionally mould-ripened, which can be trimmed and which must be discarded helps reduce both unnecessary waste and food-safety risks.

Why Does Mould Grow On Cheese, And Is It Always Dangerous?

Different varieties of cheese react to mould differently based on properties such as moisture content, acidity, texture and how long it is aged for. In some cases, mould is deliberately introduced during the cheese-making process; in other situations, mould develops naturally after the package is opened, due to exposure to mould spores. 

The process of cheesemaking involves the addition of certain bacteria that transform lactose into lactic acid, which enhances flavour and also changes the acidity of the cheese. Later on, the addition of mould culture provides other modifications. For instance, blue cheese features the mould Penicillium roqueforti that gives it blue-green tones, while Brie and Camembert contain mould culture to form their characteristic white rinds. 

However, unwanted mould cannot be detected simply by sight. Some fungi can form toxins, and unwanted growth can exist along with pathogenic bacteria. Therefore, just because a piece of cheese looks fine does not mean that it is safe to eat.

Which Types Of Cheese Are Safe When Mould Appears?

The most useful distinction is between mould that belongs to the cheese's intended production and mould that appears unexpectedly. Use this comparison when deciding what to do.

These recommendations follow established food-safety guidance on mouldy cheese. Even varieties deliberately ripened with mould can develop unwanted growth, so a familiar rind does not make every new patch safe.

How Can You Save A Block Of Cheese With Unwanted Mould?

Hard cheeses typically exhibit a more rigid consistency but usually have lower moisture content than soft cheeses. As a result, the chances of the mould penetrating are lower, although cutting should be done only in favourable conditions.

To cut a hard cheese, for instance, cheddar cheese, you should abide by the following steps:

• Cut generously: Make sure you cut at least 2.5 cm (one inch) away from the visible mould on all sides.

• Avoid dirtying the knife: Do not allow the knife to touch the mould before getting into the uninfected cheese.

• Isolate the remaining cheese: Keep the unaffected part away from the affected part and also use a clean knife and board.

• Examine carefully: If the mould is widespread, then the cheese might be heavily spoiled or have its own unusual smell or appearance. In this case, throw it away.

This method is not applicable to cottage cheese, cream cheese, ricotta cheese, mozzarella or anything shredded or sliced because their moisture makes it difficult to avoid the risk of contamination.

Why Are Soft Cheeses More Vulnerable To Mould Contamination?

Moisture is an important element in the way contamination acts. Soft cheeses are usually characterised by higher moisture content than aged firm cheeses, allowing for the spread of mould and some harmful bacteria to places that are not visible. Additionally, their texture makes it hard to slice the contaminated part without affecting the quality of the entire cheese.

Cottage cheese, ricotta cheese and cream cheese should be thrown away when mould is spotted. The same rule applies for mozzarella cheese and fresh cheese and for shredded, sliced or crumbled cheese. Just slicing the part with the mould or cooking the cheese is not enough to get rid of the contamination.

People who are pregnant, older adults, young children and people with weakened immune systems should be particularly cautious about foodborne illness. Choosing properly stored, pasteurised products where appropriate and following package instructions are important precautions.

What Cheese Safety Tips Help Prevent Mould Growth?

Proper storage slows down spoilage, but it is not a guarantee that cheese will not spoil and remain usable forever. Consider these easy steps when storing cheese:

• Maintain proper temperature in the fridge: Keep it at or below 4 °C (40 °F).

• Properly seal the cheese: Use proper packaging material or a container with a lid to minimise air and contamination.

• Use clean utensils: Never touch cheese with dirty hands or use a knife that has been in contact with other food items.

• Pay attention to the labels: Follow storage instructions and make sure to use the cheese within a reasonable time after opening.

• Don't mix cheese with questionable goods: Keep the uneatable cheese away from food and sanitise any surface or container that has touched it.

• Prevent long-term exposure to room temperature: Always put perishables in the fridge within two hours or one hour in temperatures above 32 °C (90 °F).

These tips are helpful for all kinds of cheese; still, they are especially vital for fresh cheese because it has more liquid in it. If you aren’t really sure if the cheese has a good rind or has mould, it is best to throw away the cheese instead of taste-testing it.

Conclusion

Mould is essential for the making of certain cheeses, but unwanted growth should raise red flags. Certain strains create the taste of cheeses like blue cheese or soft-ripened varieties, but not all strains are safe. Sometimes, hard cheese can be cut and saved. However, soft cheeses should be discarded when the mould appears. When in doubt, safety is more important than not wasting food.