Here is a simple answer to whether and why can cheese be left out overnight even though cheeses have different duration of how quickly they spoil.
Cheese historically has served to preserve milk for a long time. Therefore, many kinds of cheese by design can last overnight or longer without refrigeration.
Hard, or semi-hard cheeses, like mozzarella, cheddar, jack, gouda, swiss, Italian, and other types, can be left out of the refrigerator overnight. If a place is not too hot, too humid, and away from direct sunlight without any problem.
However, soft cheeses, like cream cheese, cottage cheese, usually deteriorate quickly without refrigeration and should not be left out of the fridge overnight.
The above is an oversimplified answer which requires qualification and clarification. For example, what is the kitchen temperature overnight? Is it heated? Are we talking about cold winter or summertime?
Read below in the article about specific types of cheeses and if they can stay out long enough and be safe.
In the wintertime, I sometimes leave some food on the floor in the package or even in the pot. It cools down and stays fine to eat. Cottage cheese, for example, maybe just fine in winter on the floor. That is because cold air settles down and hot air goes up – high school level physics.
That is why in winter, I feel safer leaving any cheese overnight outside of the fridge. But in the summer, I probably would not leave it because it will be too hot.
We are not discussing insects who may gather to bite your cheese so generously left for them by you.
I decided to do some heavy research on this topic. Below I am laying out the information I was able to find. Read on. It might be interesting.
How long can cheese be left out without spoiling?
I have eaten hard cheese, which was out for 2-4 days without refrigeration without any problem whatsoever.
The harder is the cheese, the longer you may leave it out without spoiling, including way longer than overnight.
Hard cheese, which was smoked or aged, and vacuum packaged may last for much longer than overnight, even if left out. I have read on forums that some people left out for months cheeses that are aged, but I would disapprove of such practice.
Processed cheese may last for days or sometimes weeks without refrigeration because manufacturers add preservatives to such cheese products. For example, natural cheese, made by farms, usually contains no preservatives and will start spoiling sooner.
Cheeses can easily survive days or weeks. It would be best not to refrigerate some of them according to some manufacturers’ consumption guidelines, mainly in Europe. Then, it depends on circumstances, so do it at your own risk.
To be safe – refrigerate your cheese and leave out the only part you will consume within 8-12 hours. If you see any signs of mold on your cheese that is not brie or camembert type supposed to have mold, it is time to discard it.
Cheeses are vastly different. While some can last overnight or longer without a problem, other cheeses may go bad much sooner. It depends on many factors, including original raw milk and the manufacturing process.
With that, I have reviewed forums and found that many people leave their cheese out for days at a time and report that it was acceptable to eat those. Even softer cheese like blue or Bree may last fine overnight without refrigeration.
It is worth noting that before selling some expensive hard cheeses in grocery stores, factories develop them. Some of them lie on shelves for weeks or even months (or even years) at the cool cellar temperature.
Few rules for keeping the cheese good
If you leave the cheese out, leave it in the coolest part of the kitchen – usually closer to the floor and out of direct sun rays.
It would be best if you kept cheese in the dark place to last longer. Put it in the basement if you have one. Just make sure you protect it from any curious mice, or you will face a classical mice & cheese problem.
Many kinds of cheese left out in a dry climate will last longer than in a humid environment because moisture enables bacteria breeding. To say, in Arizona, cheese can be left out overnight more safely than in Florida, for example. And probably more safely than on hot, humid nights in Minnesota.
Suppose cheese is in an unopened sealed manufacturer’s package. In that case, it has better chances of staying excellent and fresh overnight or longer. Vacuum-sealed is the best. Once you open sealed packaging, air comes in and allows bacteria to start developing quicker, spoiling the cheese sooner. In a closed (sealed) package, mold can still develop. Still, it takes longer to grow for mold in contrast with bacteria, which spreads faster.
One of the old tricks to keep hard or semi-hard cheese good is to cover it well to prevent air from coming in. For that purpose, you can use a glass jar or glass block (preferably), a regular cooking pot, or a plate covered with plastic wrap. This method may preserve cheese for longer, sometimes for days or a week, or even longer.
I had left hard cheeses overnight by putting them on a clean plate and covering them with another plate. Or in a container. And I ate them simply fine.
For example, in France, they do not refrigerate their cheese. And in Italy, pizza makers sometimes purposely leave cheese overnight before putting it on pizza to make it softer.
Note: once you cut that thick outer shell of hard cheese, the spoiling process accelerates. Smaller pieces spoil quicker than a large portion of cheese.
Let us recap – for the cheese to survive longer at room temperature, you must keep it:
- In the dry place, keeping cheese dry,
- Where it is dark,
- Not hot, preferably less than 75F degrees,
- Well covered or packaged to prevent airflow,
- Do not contaminate cheese with other food or utensils,
- Do not touch it with dirty hands,
- Make sure to use a clean container where you keep your cheese.
How do you think people were storing cheese for thousands of years before the invention of the refrigerator? That is right – in caves and cellars in cool but not fridge temperature.
Important note! We are talking about plain cheeses left by themselves without anything else added. Suppose cheese is mixed in any food, like in a salad with mayonnaise or the cooked pizza. In that case, it will go bad sooner due to contamination by bacteria from other food.
Therefore, the verdict is that you can leave hard cheeses overnight out of the fridge without much problem.
What about cheddar or mozzarella cheese left out overnight?
For example, cheeses such as Grana Padano, Parmesan, or Pecorino age for months or years before being sold to a consumer. Source. Such cheeses have low moisture components and can stay good for a long time without refrigeration. Do you think it will hurt such cheese to stay one more night or a few more days? I do not think so.
Other cheeses like cheddar or mozzarella are usually considered-semi hard. You can even feel they are softer because of higher moisture content. More moist cheeses can go bad sooner (hence, the recommendation to keep cheese dry.) Leaving them overnight is usually fine. Few days – maybe, if you follow the rules I laid out above. A week or longer is usually too much. Some semi-hard cheeses may not stay good that long.
Soft cheeses like Brie and Neufchâtel are soft-type cheeses that mature for up to a month. Source. Thus, most likely, you can leave them overnight without problem too. Camembert cheese also ages from few days to few weeks to develop its trademark mold. I left it overnight without a problem. By the way, Camembert is developed (aged) in humid conditions. Therefore, I think it should survive humid kitchen overnight simply fine. Blue cheeses also develop for some time and can survive more than one night out.
Gouda is the cheese that goes through a process of aging, just like cheddar. It would be best if you did not refrigerate Gouda cheese for consumption. So, we probably can safely say that any complex and many semi-hard aged kinds of cheese can easily survive a night at room temperature. That includes cheddar and mozzarella.
Cheese usually tastes better at room temperature than when it is cold from the fridge. Many chefs serve cheese at room temperature. Please correct me if I am wrong.
Tip: What to do if my cheese went too soft? If you want to firm up soft cheese – put it in the refrigerator. Within 1-3 hours, cheese should firm up in the cold fridge.
Can shredded cheese be left out overnight?
Recall that cheese cut into smaller pieces will start spoiling faster than a large portion. That is, cutting cheese into shredded cheese will speed up its deterioration because it consists of many small pieces. Still, shredded hard cheese most likely will be fine after a single overnight stay in the kitchen at a normal temperature, especially if you take the precautions mentioned above.
Can cream cheese be left out overnight?
I pretty much answered this question earlier in this blog post. Cream cheese is not matured, and leaving it overnight may be risky. But occasionally, I did that, later ate it, and I was fine.
Still, cream cheese is not designed to last long. It does not go through the process of aging at the factory. The thing is, if the environment in the kitchen is cool, dry, dark, it may still be ok if left out overnight. Maybe even longer, if in winter. But cream cheese does not taste as good when it stays out for too long.
Can string cheese stay out overnight?
The same thing – string cheese is not aged, but manufacturers in the USA usually add preservatives. It is also made from pasteurized milk. Therefore, it should also survive overnight under proper conditions. Not if hard and aged cheeses, though. Do not expect it to last weeks or even a week in the open.
If string cheese is still in a sealed package, then it may survive even for a week. Depending on how long it traveled from the factory to store and how fast someone purchased it.
What does USDA say about refrigerating cheese?
Cream cheese, cottage cheese, shredded cheeses and goat cheese must be refrigerated for safety. Cheddar processed (American), block and parmesan do not require refrigeration, but fridge will extend their life. USDA.
Conclusion.
Most cheeses will survive overnight perfectly fine, especially by taking precautions I described in this blog post. Pretty much all hard and semi-hard cheeses will last longer than only overnight. They may soften more, but that is even tastier for, according to many people. And even some soft cheeses can easily survive overnight without a refrigerator.