Detecting Spoiled Cheese: A Quick Guide To Freshness

Cheese is a perishable food and can sometimes be tricky to determine if it has gone bad. Each cheese ages differently and therefore spoils differently. The three main attributes to look out for when determining if your cheese has gone bad are smell, appearance, and taste. If a mild cheese, like Monterey Jack or American, smells strong, like blue cheese or Limburger, then it's time to throw it away. If you notice mould on a hard cheese that hasn’t spread to the entire cheese, you can just cut out the mould and the area surrounding it. Be sure to check carefully that there’s no mould on the rest of the cheese before eating it.

Smell: an off scent, like ammonia, refrigerator, freezer, sour milk, or vinegar, can indicate bad cheese

Smell is one of the best ways to determine whether your cheese has gone bad. As cheese is a dairy product, an "off" scent can indicate that it has spoiled. This can be the smell of sour milk, ammonia, or even a refrigerator or freezer. If a usually mild cheese has developed a strong smell, similar to blue cheese or Limburger, it has likely gone bad.

When a strong-smelling cheese has gone bad, it will often have a very strong ammonia smell, similar to cat urine. If you are familiar with the cheese, and it smells like a much more concentrated version, it is probably no longer safe to eat.

It is a good idea to smell your cheese when you first purchase it, so you know how it should smell. This will help you notice any changes. Some cheeses can be pungent and "off" smelling to begin with, so it is important to use other indicators as well. For example, appearance and taste can also be good indicators of whether cheese has gone bad. However, if a cheese smells bad, it is probably best to trust your senses and throw it away.

Appearance: thick mould, discolouration, or changes in texture, like sliminess, oil, or bloated packaging, can be signs of spoilage

When it comes to the appearance of cheese, there are several signs that can indicate spoilage. Thick mould growth is one of the most obvious signs that cheese has gone bad. If your cheese is covered in thick mould, it's probably not worth saving. However, small amounts of surface mould can be trimmed off, and the rest of the cheese can be consumed as long as it shows no other signs of spoilage.

Discolouration is another indicator that your cheese has gone bad. This can occur due to oxidation or exposure to air, which can also result in a slimy or sticky texture. Changes in texture, such as sliminess, oil, or bloated packaging, can also be signs of spoilage.

In addition to mould and discolouration, you may also notice other types of fuzz in different colours or textures on the surface of the cheese, which is another sign that it has gone bad. White, green, or black mould on the surface of the cheese indicates contamination and should be discarded.

Taste: a sour or unpleasant aftertaste is a clear indicator of cheese gone bad

Taste is often a last resort when it comes to determining whether your cheese has gone bad. This is because it requires you to put a piece of the cheese in your mouth, which may be unpleasant if the cheese is spoiled. However, it is sometimes the only way to know for sure.

If you suspect your cheese may be spoiled, it is recommended that you only taste a small piece. This will be enough to determine whether it has gone bad. If the cheese has a sour or unpleasant aftertaste, it has likely gone bad. This may be accompanied by a bitter or acidic taste.

Tasting cheese is especially important if you are unfamiliar with the appearance and smell of the specific type of cheese. For example, some French soft cheeses have a white, fuzzy exterior that resembles bad mould but is completely safe to eat. In this case, tasting the cheese may be the only way to know for sure if it has gone bad.

It is important to remember that even the stinkiest cheese has been cultured and aged in very controlled conditions. A pungent cheese will still taste pleasant to a connoisseur. When it has gone bad, it will taste overly bitter or sour, or have a musty quality to it.

Type of Cheese: soft cheeses, like Brie, are more prone to spoilage and should be consumed within a week of opening

Soft cheeses, like Brie, are more prone to spoilage than harder cheeses. This is because they have a higher moisture content, which makes them susceptible to bacterial growth. Therefore, soft cheeses should be consumed within a week of opening.

When it comes to determining if your soft cheese has gone bad, there are several signs to look out for. One of the most obvious signs is the presence of mould. Soft cheeses like Brie already have a natural, edible white mould on their surface. However, if you notice any dark spots or green dots, this indicates spoilage and the cheese should be discarded.

Another indicator of spoilage is a change in smell or taste. Brie is known for its mild and creamy characteristics. So, if your Brie starts to smell sour or pungent, or tastes unpleasant, it has likely gone bad.

Changes in texture can also signify spoilage. If your Brie becomes dried out, lumpy, or excessively runny, it is probably past its prime.

To prolong the shelf life of soft cheeses, it is important to practise proper storage. Always store soft cheeses in the refrigerator, and ensure they are well-wrapped or sealed in airtight packaging. Additionally, maintain good cheese hygiene by using a clean knife to cut the cheese, preventing the transfer of bacteria and other food substances.

In summary, soft cheeses like Brie are more perishable and should be consumed promptly. By regularly examining the appearance, smell, taste, and texture of the cheese, you can help ensure that you catch any signs of spoilage and avoid consuming bad cheese.

Storage: improper storage, like exposure to light, can cause spoilage

When storing cheese, it is important to remember that light is bad for cheese. Exposure to light can cause light oxidation, which is facilitated by both natural and artificial light sources. Leaving cheese in direct sunlight or exposed to bright LED lights will cause spoilage.

Light oxidation occurs when oxygen from the air attacks fat molecules, proteins, and vitamins in the cheese. This sets off a chain reaction that can cause significant damage to the cheese. This process is also known as lipid oxidation or photo oxidation.

The most visible effect of light oxidation is discoloration. Beta-carotene, a compound found in high levels in cow's milk and responsible for the yellow colour of most cheeses, is broken down during oxidation. As a result, the exposed part of the cheese will lose its yellow colour and appear whiter.

Light oxidation also affects the flavour of the cheese. The oxidation process produces a large number of smaller molecules that can lead to off-flavours often described as "plasticky" or "cardboardy".

Additionally, light oxidation can impact the smell of the cheese. Most cheeses contain an amino acid called Methionine, which, when oxidised, produces a compound called dimethyl disulphide—the smell of boiled cabbage or potatoes.

To prevent light oxidation and ensure the quality of your cheese, it is essential to protect it from light exposure during storage. Store cheese in opaque containers or wrap it in paper or plastic to shield it from direct light. By taking these precautions, you can prolong the shelf life of your cheese and maintain its intended flavour, colour, and aroma.

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