Cheese Lifespan: How Long Does It Last After Opening?

Cheese is a kitchen staple thanks to its rich flavour and versatility, but how long does it last once opened? The answer depends on the type of cheese and how it's stored. Soft cheeses like mozzarella, feta, and Brie contain more moisture, so they're highly perishable and should be consumed within one to two weeks of being opened. Harder, aged cheeses like cheddar and parmesan, on the other hand, can last in the fridge for up to four months if unopened, and about six weeks once opened. Semi-hard to semi-soft cheeses like Gouda and Gruyère fall somewhere in the middle, with a fridge life of about two to four weeks after opening.

Soft cheeses last 1-2 weeks in the fridge

Soft cheeses typically last between one and two weeks in the fridge after opening. This is because they have a high moisture content, which makes them more perishable than harder cheeses.

To get the most out of your soft cheese, proper storage is key. For cheese sold in brine, such as feta or fresh mozzarella, keep it in the liquid and ensure the container's lid is secure. For blue cheese, you can wrap it in foil. Soft-ripened cheese, like Brie, has a delicate rind, so it needs more care than other soft cheeses. Wrapping it in cheese paper is best, but you can also use parchment paper and keep it in an airtight container.

A wedge of cheese starts to decline the moment it's cut off the wheel, and it won't improve in the fridge. So, it's best to only buy cheese for the week ahead.

After opening, you can safely store most soft cheeses in the fridge for at least seven days. However, it's always a good idea to inspect your cheese to make sure it's safe to eat, regardless of the best-by date.

Hard cheeses last 3-4 weeks in the fridge

Hard cheeses, such as cheddar, can be kept in the fridge for 3-4 weeks after opening. In fact, unopened hard cheeses don't need to be refrigerated, but they will last much longer if they are. Unopened blocks of hard cheese can last for up to six months in the fridge.

Hard cheeses last longer than soft cheeses because they contain less moisture, which means they are less prone to spoilage from bacteria. However, even hard cheeses will eventually go bad. Signs of spoilage in hard cheeses include blue, grey, or green mould, dryness, and a strong smell. If you see any mould on a hard cheese, simply cut off at least one inch around and below the mouldy spots. If you have a healthy immune system, you're unlikely to get sick from accidentally eating a small amount of mould. However, you should monitor yourself for symptoms of food poisoning, such as vomiting, stomach pain, or diarrhoea.

White specks or crystallised patches on certain aged hard cheeses, such as cheddar, parmesan, and gouda, are normal and safe to eat. These spots are most likely not mould but calcium lactate crystals, which form when the lactic acid in the cheese combines with calcium.

To maximise the shelf life of hard cheeses, wrap the cheese in wax, parchment, or cheese paper, then cover with plastic wrap before refrigerating. Alternatively, wrap the cheese first in parchment paper, then place it in a Ziploc bag to limit airflow and keep the cheesy smell from affecting other foods in the fridge.

Freezing cheese changes its taste

Freezing cheese is a great way to make it last longer, but it's important to note that freezing will change the texture and taste of the cheese. While it is safe to freeze cheese, the quality of most cheeses will suffer as a result of being frozen. Ice crystals form in the cheese during storage, which affects both its taste and texture. The expansion of water when it freezes and its contraction when it thaws break down the molecular structure of the cheese, causing it to become crumbly and dry.

Soft cheeses, such as camembert, brie, ricotta, and cottage cheese, are particularly susceptible to texture changes when frozen. They can become tough, crumbly, and exude liquid after thawing. Fresh cheeses like queso fresco and paneer also suffer significant texture changes when frozen. Hand-crafted, artisanal cheeses with delicate flavours can also be noticeably affected by freezing, losing their delicately balanced flavours.

On the other hand, industrially-produced cheeses, such as large blocks of store-bought cheddar, are less affected by freezing. Well-aged, hard grating cheeses like pecorino Romano and Parmigiano-Reggiano (parmesan) can also withstand freezing, although they may develop a slightly metallic or "burnt" flavour. These cheeses keep well in the refrigerator, so freezing is not necessary.

If you do choose to freeze your cheese, it is best to use it within two to three months for optimal taste and texture. Harder cheeses like parmesan may last a bit longer. Frozen cheese is best used in cooked dishes, such as casseroles, grilled cheese sandwiches, or baked goods, rather than eaten fresh.

To summarise, freezing cheese can extend its shelf life, but it is important to consider the potential impact on taste and texture. Soft and fresh cheeses are more susceptible to changes, while industrially-produced and hard grating cheeses are better suited to freezing.

How to identify spoilage in soft and hard cheeses

Soft cheeses have a high moisture content (50–80%) and examples include cottage cheese and mozzarella. Hard cheeses, such as Parmesan and Cheddar, have lower moisture contents and more acidic pH levels, which inhibit the growth of bacteria.

Soft cheeses are more susceptible to spoilage than hard cheeses. Psychrotrophic Gram-negative bacteria, such as Pseudomonas spp., are commonly found in soft cheeses. Their ability to degrade lipids and fats leads to unwanted flavours and odours.

Spoilage organisms of importance in soft cheeses include psychrotrophic Gram-negative rods such as Pseudomonas, Alcaligenes, Achromobacter, and Flavobacterium, which can produce objectionable odours and flavours due to the presence of lipolytic and proteolytic enzymes.

Other spoilage organisms that can affect soft cheeses include coliforms, such as Klebsiella spp., Enterococcus spp., and Citrobacter spp., which can produce a variety of defects in cheese.

Yeasts and moulds can also cause spoilage in soft cheeses. Species of Candida, Pichia, Kluyveromyces, Rhodotorula, Debaryomyces, and Torulopsis have been associated with spoilage in soft cheeses such as cottage cheese and cream cheese.

When it comes to identifying spoilage in soft cheeses, there are several signs to look out for. If you notice any mould or funky smells that weren't there when you bought the cheese, it's likely that spoilage is occurring. A slimy texture is also indicative of spoilage.

If you see any mould on soft cheeses, it's best to discard them, as mould can invade quickly. Ricotta, cream cheese, and cottage cheese should be thrown out if any mould appears.

Hard cheeses are less prone to spoilage than soft cheeses due to their lower moisture content. However, they can still be susceptible to spoilage from bacteria and mould.

Coliforms, Clostridium spp., and moulds are examples of microbes that can proliferate in some hard cheeses. One common defect in hard cheeses is late gas blowing, caused by Clostridium tyrobutyricum. This can cause sponge-like defects and a rancid taste in the cheese.

Another sign of spoilage in hard cheeses is the presence of red or black mould. White specks or crystallised patches on aged hard cheeses are usually safe to eat and are most likely calcium lactate crystals.

To summarise, spoilage in soft cheeses is indicated by the presence of mould, funky smells, or a slimy texture. Soft cheeses with any mould should be discarded, especially ricotta, cream cheese, and cottage cheese.

Spoilage in hard cheeses can be identified by the presence of red or black mould or other defects such as late gas blowing. White specks or crystallised patches are usually safe to consume.

How to store cheese to extend its shelf life

The shelf life of cheese depends on the type of cheese and how it's stored. To extend the shelf life of cheese, it's important to store it properly. Here are some tips on how to store cheese to extend its shelf life:

Wrapping and Packaging

• Avoid wrapping cheese in tight, non-porous material like plastic wrap, as this can dry it out and harden it.
• Instead, use porous materials like wax, parchment, or cheese paper to help maintain its moisture.
• Wrap blocks of cheese (or other types that don’t come in resealable packaging) and store them on the top or middle shelf, or in a drawer.
• For semi-hard to semi-soft cheeses, wrap the cheese in breathable parchment-type paper, then place it inside a Ziploc bag to limit airflow and keep the cheesy smell from affecting other foods.
• For soft cheeses, seal them in a little Tupperware container or plastic jar to limit airflow.

Refrigeration

• Keep the refrigerator temperature below 40°F (4°C). Higher temperatures increase the rate at which bacteria multiply, increasing the risk of spoilage.
• Place a thermometer in the warmest spot (near the door) to monitor the temperature.
• Store cheese above raw meats, poultry, and fish to avoid contamination.

Freezing

• Cheese can be frozen to extend its shelf life, but it may change its texture and taste.
• Freeze cheese before the number of days shown for refrigerator storage has elapsed.
• Cut the cheese into portions no larger than 1/2 pound each, and wrap tightly in heavy-duty aluminum foil or plastic freezer wrap, or place it inside a heavy-duty freezer bag.
• Properly stored, cheese will maintain its best quality for about 8 months in the freezer but will remain safe beyond that.

Inspecting and Cutting Cheese

• Inspect hard cheeses for mold and cut off any spots, but toss soft cheeses if you see mold.
• If you see specks of blue or green surface mold on hard cheese, cut off at least 1 inch (2.5 cm) around and below those spots.
• White specks or crystallized patches on aged hard cheeses are normal and safe to eat. They are likely calcium lactate crystals, which form when the lactic acid in cheese combines with calcium.

By following these storage tips, you can extend the shelf life of cheese and enjoy it for a longer period of time.

Frequently asked questions