How to identify spoiled blue cheese

Smell the cheese. The best way to tell if blue cheese has gone bad is by smelling it. Fresh blue cheese will have a strong, sharp scent, but it will change if it starts to spoil. Give it a sniff, and if it smells like ammonia, it’s likely spoiled.

• When you first buy blue cheese, make sure to give it a sniff. This way, you’ll know what the fresh smell is like, and you’ll be able to detect any unusual odors as it ages.

Check the color. Fresh blue cheese will have mold on it, typically blue or green. However, the creamy part of the cheese will usually be white, beige, or yellowish. If you notice the cheese turning pink, brown, or green, it is likely spoiled.

• Just as with checking the smell, observe the color of the blue cheese when fresh so you can recognize any unusual changes as it spoils.
• Additionally, check the surface of the cheese for any sliminess or cloudiness, and discard it immediately if you notice any changes in texture.

Taste it. If your piece of cheese still smells and looks the same, you can differentiate by tasting it. Fresh blue cheese will have its distinctive sharp flavor, while spoiled cheese will have a more pungent taste. If you bite into a piece and find it too sour or unpleasant, throw it away.

• In most cases, tasting a small piece of spoiled blue cheese will not cause food poisoning, so this method is generally safe.

Discard cheese not refrigerated after 2 days. Blue cheese should be kept in the fridge to maintain its freshness. If left out in the open air, it will spoil much faster. In many cases, you will notice spoilage within a few days. If you accidentally leave blue cheese outside for more than 2 days, it’s best to discard it.

Discard cheese kept in the fridge for over 3 weeks. When stored in the fridge, blue cheese can last for a certain period. Always check the expiration date—most cheeses are still safe to eat 1 to 2 weeks past their expiration date, meaning blue cheese stored in the fridge can last for 3 to 4 weeks.

• To keep blue cheese fresh for as long as possible, make sure the refrigerator temperature does not exceed 4°C.

Remove cheese from the freezer after 6 months. Cheese stored in the freezer at a constant 0°C can technically be kept indefinitely, allowing you to store extra cheese to prevent spoilage if you don't plan to use it within the month. However, for the best flavor and texture, it's recommended not to keep it in the freezer for more than 6 months.

• Note that the flavor and texture of blue cheese can change once thawed. It may lose some of its sharpness and become crumbly.

Cut cheese into pieces for freezing. If you plan to store blue cheese in the freezer, it should be cut into portions of no more than 200 grams each. For crumbled cheese, divide it into equal portions. Use a food scale to measure each piece or portion before freezing.

• You can freeze blue cheese after it's opened or partially used. Just make sure to cut it into pieces or portions of 200 grams according to the guidelines.

Wrap in two layers. Whether you're storing blue cheese in the fridge or freezer, it needs to be packaged properly to stay fresh as long as possible. First, wrap the cheese in wax paper or parchment paper. Then, add an extra layer of plastic wrap or aluminum foil to prevent the cheese from drying out.

• If you're freezing the cheese, place the double-wrapped piece in a freezer bag to avoid freezer burn.
• If you're worried about the cheese absorbing odors from other foods in the fridge, place it in an airtight container after wrapping to offer maximum protection.

Store cheese in the lower part of the fridge. The colder the storage temperature, the longer blue cheese will stay fresh. Since the lower section of the fridge is typically the coldest, it's best to keep the cheese there for optimal longevity. If your fridge has a drawer at the bottom, that's an ideal spot as it is less likely to be opened frequently, which helps maintain a consistent temperature.

• If you notice any signs of spoilage when opening blue cheese, don’t hesitate to return it to the store. Bring your receipt if you want a refund or exchange.
• Blue cheese has a higher moisture content, which means it spoils faster than drier types of cheese.

• If any part of the cheese turns discolored, slimy, or cloudy, do not attempt to cut off the spoiled section and eat the rest. It’s best to discard the entire piece, as bacteria or mold may still be present inside.
• If you happen to consume spoiled blue cheese and feel unwell, seek medical attention promptly.