Refrigerators keep things fresh and prolong the shelf-life of food, this is something most people will already know.
So why does cheese still go moldy if it’s kept in the fridge? Surely it should stay fresh for weeks or months?
In this article we will be answering the question, “why does cheese mold in the refrigerator”, we’ll also be covering whether or not it’s safe to eat cheese that’s gone moldy in the fridge, and how you can prevent it from happening in the first place, so keep reading.
Incorrect storage is the number one contributor to cheese growing mold whilst refrigerated. The use of plastic wrapping can retain moisture levels past 55% humidity, which is the ideal level for mold to grow. Faulty refrigeration units and incorrect temperature settings also play a large role.
Why does mold grow on cheese in the fridge?
Mold can grow in many places as long as the environment suits it. What it needs to thrive, is moisture, darkness, a food source, and a consistent temperature.
Here are some of the main causes of mold growing on your cheese even when chilled.
Now, you’re probably thinking that mold should not be able to grow in a fridge since the temperature is too low for it to grow, that’s the whole point of refrigeration after all.
However, if your thermostat is not adjusted correctly, and the internal temperature of your fridge is above 40 Fahrenheit (4.4 Celsius), mold will be able to grow (albeit more slowly than at a higher temperature).
How you store your cheese in the fridge can also play a large part in not only whether it molds, but also how fast.
For instance, many kinds of cheese are sold in blocks covered in plastic packaging. The cheese will remain fresh for a long time whilst in its packaging and unopened.
However, once you have opened the packet, additional moisture from the foods stored in the fridge can find its way into the packaging containing the cheese. Plastic retains moisture very well, so now the mold has a consistent source of hydration.
The cheese itself is an excellent food source and the fridge remains out of direct sunlight almost constantly, so mold spores are safe from UV light which kills it. Essentially, even though you may think your fridge is preventing your cheese from going moldy, you may be giving it the ideal circumstances to grow.
How do you keep cheese from going moldy in the fridge?
Ok, so we now know why cheese goes moldy even if you’ve put it in the fridge, but how can you stop it from happening?
The list below is some of the ways that you can preserve your cheese for longer and prevent mold from forming.
- Do not use clingfilm (Saran wrap) as this will retain moisture around the cheese.
- Place it towards the front of the fridge shelf near the door. Moisture tends to condensate on the back of the fridge, so the area closest to the door will have the least moisture.
- Use a light covering of oil. Covering your cheese in a fine layer of oil will prevent air and moisture from reaching the surface of the cheese, which will prevent mold from being able to form on its surface.
- Use your salad crisper/drawer. The level of humidity in the bottom drawer of your fridge is just right to store vegetables, and also cheeses. The humidity level will retain your cheese’s moisture, allowing it to retain its texture, but dry enough to prevent mold from forming for a considerable time.
How long does it take for cheese to go moldy in a fridge?
Soft cheeses such as cottage and mascarpone, need to be kept at a minimum of 5-8 degrees Celsius (41 Fahrenheit). If stored at this temperature, these cheeses should last for at least 7 days.
For harder cheeses such as cheddar, again, it should be stored at around 41 Fahrenheit, but due to the lesser moisture content, it can last up to 3-4 weeks before you can expect to see signs of deterioration such as mold growth.
Is your fridge to blame for your cheese going moldy?
Keeping your refrigerator clean is essential if you want to stop mold from forming on not only your cheese but all of its contents.
Mold needs a food source in order to survive, and if you aren’t cleaning your fridge on a regular basis, small amounts of mold can begin to form on remnants of food.
Once this mold is formed, it can produce spores that will travel through the air and find their way onto new food items and begin to grow there also.
You should be performing a deep cleaning of your fridge at least once per month in order to keep food residue to a minimum and lower the chances of both mold and bacteria growth.
The other factor is temperature, if your fridge is faulty in any way, it could lead to food being spoiled just as quickly as if it were sitting on the kitchen countertop.
For example, a door that does not close properly will allow warm air in and cold air to escape, not only increasing its internal temperature but also contributing to condensation formation and excessive moisture levels.
The same is true for a broken gasket, as a broken or damaged seal will again allow warm air to enter and cold air to escape.
Broken or faulty thermostats are another common cause, as if your fridge cannot reach the appropriate temperature, you may believe your food items are being stored correctly, but they may actually be warm enough for molds and bacteria to begin to breed.
Should cheese be stored in an air-tight container in the fridge?
You may think that storing your cheese in an airtight container (such as Tupperware), would be the best bet when fighting mold growth, but you might be sacrificing the quality of your cheese by doing so.
Expert cheese mongers have stated that storing cheese in an airtight container will not allow the cheese to “breathe”, which can reduce its flavor and harm its texture. Instead, they suggest if you plan to use plastic containers to store your cheese, you should poke several holes in the container lid, and wrap the cheese in a porous material such as baking paper for an extra level of protection.
Does putting sugar cubes next to cheese in a fridge stop it from going moldy?
You may have heard that adding a sugar cube to the container you store your cheese in can help ward off mold growth and keep your cheese fresher for longer.
The concept behind this idea makes sense, as the sugar cube will absorb excess moisture within the container which can lead to mold growth. However, the precaution to take here is to not store your cheese for too long in this way, as if too much moisture is drawn from the cheese, it can become dry and begin to crack, spoiling its overall texture.
Why does cheese go moldy in the fridge before its expiration date?
As long as you are storing your cheese at the correct temperature (recommended by the producer), it should be lasting until the expiration date provided.
If you are seeing that cheeses and other foods you are buying are frequently going bad before their expiration date, check the temperature settings and your fridge for any faults.
There is also the possibility of cross-contamination, causing the cheese to mold quickly in the fridge. For example, directly touching the cheese with unwashed hands can spread mold spores from the outside world directly onto the cheese without any mold patches necessarily being nearby.
Will vacuum packing stop cheese from going moldy in the fridge?
Vacuum-sealing hard cheeses such as Gouda or Pecorino will help to slow down mold growth during refrigeration.
It’s important to do this correctly though, or the quality of your cheese could suffer.
Wrap your cheese in a piece of porous material such as parchment paper, this will help to absorb any excess moisture.
You also need to make sure you do not touch the cheese with your bare hands, as you will be trapping the air in the bag that is being sealed in, so if mold spores find their way onto the cheese before it is sealed, it is likely that mold will grow during storage.
Vacuum-sealed cheeses should last in the refrigerator for several months if the vacuuming process is carried out correctly.
If cheese can “age” for months, why does it go moldy so quickly in the fridge?
When hard cheeses are aged, they are dipped in a brine solution that prevents bacteria and molds from being able to survive on their surface.
These cheeses are aged in large blocks, which are then cut into smaller portions to be sold. The outer layer of protection is no longer present on the cheese you will have purchased, so if left in your refrigerator under the correct circumstances, mold will be able to settle on and begin to grow on the outer surface of the cheese.
Can you freeze cheese instead of keeping it in the refrigerator to prevent mold?
Freezing cheese can increase its shelf life, as mold cannot grow in temperatures lower than 40 degrees Fahrenheit. However, freezing and thawing cheeses can break down their structure, resulting in dry, crumbly textures with a loss of taste, and in some cases, degrades their ability to melt in a satisfactory manner.
Do different cheeses last longer when refrigerated?
Hard cheeses will generally last longer in the fridge when compared to softer cheeses.
For example, hard cheese such as cheddar can be expected to last several weeks in the fridge before mold may begin to grow, or even several months of vacuum packing (as explained above), however softer cheeses such as ricotta will last only a matter of days before they begin to go past their best. This is mostly due to the higher moisture levels in softer cheeses.
Examples of cheeses that last the longest in the fridge before becoming moldy and deteriorating, in general, are listed below from longest to shortest.
Hard cheeses – 3-4 weeks
Medium cheeses – 1-2 weeks
Soft cheeses – 7-10 days
Mold can affect any foodstuff you place in your refrigerator, however, keeping it chilled certainly does slow down the rate that it can grow and spread.
Ensuring your cheese is sorted correctly and within the correct temperature ranges is your best bet at keeping it mold-free for as long as possible.