Hard cheeses are often sold in large quantities, and so it’s easy to have a leftover block of Pecorino, especially when most recipes only require a few tablespoons to finish off a dish. So, what happens when you forget the rest of the block in the back of your fridge?
Does hard cheese go bad?
Like all cheeses, hard cheeses like parmesan (Parmigiano Reggiano, when coming from Italy), Asiago, and Pecorino Romano do eventually spoil, though the process takes a lot longer than with softer cheeses. Typically, a piece of hard cheese has a shelf life of up to nine months, if properly stored. Grated and shredded hard cheeses have a shorter shelf life, as there is more surface area in contact with the air, and can last in the fridge for up to two months.
Image used under Creative Commons from Bob Peters
Though pieces of hard cheese are often sold wrapped in plastic, it’s best not to store cheese in this way long term, as this can result in off flavors and a decreased shelf life. Pieces of hard cheese should be tightly wrapped in wax paper, and then placed in a sealable bag, that is sealed only partway. This will protect the cheese, while still allowing for sufficient airflow. Grated or shredded hard cheese should be stored in sealed containers. The cheese should be stored in the cheese drawer of your refrigerator, making sure that the temperature is below 40 degrees Fahrenheit, but above freezing.
Signs of Spoiled Hard Cheese
Hard cheeses do not spoil as quickly as their softer counterparts due to a lower moisture content, and often longer aging periods. Because of this, hard cheeses do not grow mold very often, though mold on a cheese does not necessarily indicate that the cheese has gone bad. Most mold may be safely cut off, and the remaining cheese enjoyed. This holds true for whole pieces of hard cheese, though shredded or grated cheese that has grown mold should not be consumed.
Hard cheese is already quite low in moisture, but should not be eaten once dried out too much. You might notice this happens if a piece of hard cheese is left at room temperature for too long (beyond 24 hours). The surface will become dark and shiny, as moisture leaves the cheese, and the fat rises to the surface, indicating that the cheese has gone bad. Eventually, the cheese will take on a sour or rancid smell. This can also happen to cheese that has been in the refrigerator, though it may take months to occur.
Hard cheese can also go bad when exposed to too much moisture over a period of time. If you notice the cheese has become spongey or wet, and has an off smell, it should not be consumed.
Storing Hard Cheese
Hard cheeses may be frozen to extend their shelf life for up to six months. Though freezing cheeses typically results in a taste and texture change, this is far less noticeable with hard cheeses as their moisture content is already so low. Hard cheese that has been frozen may still be used in any cooked dish, with no noticeable difference, though thawed cheese is not really suitable for dishes that focus on uncooked cheese, like salads or cheese platters.
Blocks of cheese should wrapped in wax paper and then sealed in an airtight container before freezing. Grated or shredded cheeses should also be stored in an airtight container. Hard cheeses may be frozen for up to six months, so while it makes sense to freeze a block of cheese that has already been in your fridge for quite a while, fresh cheese should be kept in the refrigerator for as long as possible.
To thaw the cheese, place the sealed container in the refrigerator overnight. Do not thaw at room temperature, as this will introduce too much moisture. Cheese should not be frozen again, so be sure to use as much as possible once it’s thawed! Ideally, hard cheese that has been thawed should be used within a week.