Parmesan cheese is a versatile ingredient that can be used in a variety of dishes, from pasta to salads and even as a garnish. But have you ever wondered what happens if you don’t refrigerate Parmesan cheese?

The Short Answer

The short answer is that it depends on the type of Parmesan cheese. If it’s freshly grated, then it needs to be refrigerated to prevent spoilage. However, if it’s a block of Parmesan cheese that hasn’t been opened yet, then it can be stored at room temperature for up to several months.

Freshly Grated Parmesan Cheese

When you grate Parmesan cheese, you’re essentially creating more surface area for bacteria to grow on. This means that freshly grated Parmesan cheese needs to be refrigerated to prevent the growth of harmful bacteria.

If you leave freshly grated Parmesan cheese out at room temperature for too long, it can start to spoil and develop mold. This can lead to food poisoning if consumed.

It’s important to note that even if you do refrigerate freshly grated Parmesan cheese, it still has a relatively short shelf life. It’s best to use it within a week or two for optimal freshness.

Unopened Block of Parmesan Cheese

If you have an unopened block of Parmesan cheese, then you don’t need to refrigerate it right away. In fact, many people store their unopened blocks of Parmesan cheese at room temperature.

This is because Parmesan cheese is a hard and aged cheese that doesn’t contain much moisture. The lack of moisture makes it less susceptible to spoilage and bacterial growth.

However, once you open the block of Parmesan cheese, then you should refrigerate it like any other dairy product. This will help prevent the growth of harmful bacteria and keep the cheese fresh for longer.


In conclusion, it’s important to refrigerate freshly grated Parmesan cheese to prevent spoilage and bacterial growth. However, if you have an unopened block of Parmesan cheese, then you can store it at room temperature for several months.

Remember to always check the expiration date and use your best judgment when it comes to food safety. With proper storage and handling, Parmesan cheese can be a delicious addition to many dishes.

Quick Tips:

  • Always check the expiration date before consuming any dairy product.
  • If you’re unsure whether a dairy product is still good, trust your senses and look for signs of spoilage.
  • When storing Parmesan cheese in the refrigerator, make sure it’s in an airtight container to prevent moisture from getting in.