Cheese is arguably the best invention since the wheel; well, it actually came way before that. It is a craft that has been practiced and perfected over thousands of years to create a wide variety for you to choose from.
However, with so many options available at the tip of your finger, there always tend to be a bunch of leftovers in the fridge. But, can hard cheese go bad?
Unfortunately, hard cheese creates one of the most favorable environments for bacteria to thrive on. It provides moisture, no matter how hard and aged the cheese might be. It provides oxygen, due to the storage methods required. And, it allows for plenty of time when it sits in the fridge.
So does this mean you can’t ever enjoy hard cheese again? Luckily, that is where we come in; to help guide you through the time-frames and storage conditions to optimize the shelf life of your favorite hard cheese. Continue reading to learn this and so much more!
A Look at Hard Cheeses
Before starting, it is important to understand the structure of hard cheese that will help us understand how long it will be able to last as well as the possible signs of expired cheese.
To be classified as a hard cheese, the cheese itself needs to have a moisture content below 50%. Anything higher will be classified as a soft cheese.
If you need an easy way to remember this; softer cheeses are soft because of all the moisture and harder cheeses are hard because of the lack of it.
The way they reduce the moisture content to create a hard cheese is by allowing the cheese to age. While the cheese is aging, the curds separate from the whey (the moisture).
Another step some hard cheeses undergo is the addition of enzymes like rennet. In the short versions, after many steps, the enzymes help extract more moisture (whey) and create an even harder cheese.
What makes hard cheese so fascinating is that they can be aged anywhere from a few weeks to months to even a couple of decades!
As with virtually all cheeses, milk is the base ingredient used to produce cheese. This milk can come from any milk-producing mammals like cows, sheep, goats and even buffalo’s.
Different types of hard cheeses will undergo different aging methods and times, but in the end, they all have similar characteristics and a general guideline can be set out on how long they last and the signs that they have gone bad.
The most popular hard cheese varieties include:
- Cheddar (aged)
- Swiss cheese
- Pecorino Romano
When different ingredients, even the different types of milks are used, it affects the moisture content of the cheese and thereby the expiry date.
Can Hard Cheese Go Bad?
Cheese is such an amazing and versatile ingredient. It goes great with virtually any meal, any time of the day, and can be used at any occasion in some way, shape or form.
Unfortunately, especially if you love to experiment with a ton of different cheeses, you end up having a bunch of half-opened packets left in your refrigerator.
But can it go bad? Although hard cheese will last longer than their softer counterparts, they can still go bad.
Bacteria need three things to survive and thrive; moisture, oxygen and time.
Hard cheese has a moisture content of 50% at most, but even that is more than enough moisture for bacteria to reproduce. As we have mentioned before, different cheeses will have different moisture contents and therefore expire at different rates.
A lot of cheese, if not all of them, requires oxygen to breathe. By sealing cheese in an airtight container, the lack of oxygen could change the texture and flavor of the cheese.
Because a lot of the harder cheeses have such a specific and sharp taste, it isn’t used as often as say Gouda or cheddar (which can be used in virtually anything). This means that the cheese ends up sitting in the fridge for a long time before being completely used up.
This means that cheese is the perfect product for bacteria to live on. This is why it is extremely important to know your cheese and know its shelf life.
How Can You Determine The Shelf Life Of Hard Cheese?
Cheese is extremely susceptible to bacteria and poses major health risks. That is why it is required by law in every country that all types of cheeses have an expiry date printed on them.
This is the easiest way to determine the expiry date and should be followed to the day.
If by some impossible chance, there isn’t an expiry date on your cheese, there is a general timeline you can follow to determine the expiry date.
Remember, this timeline only applies to hard cheeses with a moisture content below 50%.
Firstly, two main factors will affect the timeline of your cheese; whether they have been opened or not and the firmness of the cheese (affected by the moisture content).
Unopened cheese will last longer as it hasn’t been exposed to oxygen yet. Once opened, the expiration speeds up considerably.
If you have a very hard cheese like Parmesan or Pecorino, it will last a lot longer than a less firm hard cheese like Cheddar or Gouda.
Unopened hard cheeses can last anywhere between 4 weeks to 6 months. Once opened these cheeses can last anywhere between 1 – 6 weeks.
Shredded or crumbled cheese will only have a shelf life of a couple of days, a week at most for the very hard cheeses like Parmesan.
Keep in mind that the only way they will be able to last that long is if they are stored in proper conditions.
How Long Does Hard Cheese Last?
Remember, the harder the cheese, the lower the moisture content and the longer it will last.
This means that cheeses like 18-month matured cheddar, Parmesan, Parmigiano-Reggiano, and Grana Padano (to name a few) will last unopened, anywhere between 6-9 months and opened, 4-6 weeks.
Cheeses that are less hard (or semi-hard) like unaged cheddar, Gouda, Edam, Emmental and Swiss cheese will last unopened between 1-2 months and opened 1-2 weeks.
Cheeses between hard and semi-hard, like a 6-month matured cheddar, will last unopened between 4-6 months and opened between 3-4 weeks.
Grated hard cheeses will last anywhere between 1-2 weeks, depending on the type of cheese it is and if any anti-caking (preserving) agents are present.
How to Store Hard Cheese?
Storing cheese is fairly straight-forward and shouldn’t be done in any other way.
Hard cheeses can be wrapped in wax paper to prevent the cheese from drying out. Do not wrap the cheese in saran or plastic wrap! This might cause the cheese to sweat inside the packaging and alter the flavor.
Cheeses can be stored in the refrigerator away from other produce (like onions and garlic) that can alter its flavor. Hard cheese is pores and can easily take on the flavor of other ingredients.
Keep the cheese in the fridge between 40-53°F (4-11°C).
Cheese should never and under no circumstances be left outside for more than 2 hours. It will start to sweat and change its characteristics.
How Can You Tell If Hard Cheese Has Gone Bad?
As we have shown, cheese is very susceptible to bacteria and therefore it is very easy to tell whether or not it has gone bad.
The first and most obvious sign is the expiry date. If the cheese has gone past it, or past the average periods we have set out above, then you should discard the cheese.
The second very obvious sign is mold. Hard cheeses aren’t inoculated with mold (like blue-veined cheese) and therefore shouldn’t have any mold present. When mold does grow on the cheese, you have two options;
- If the piece the mold has grown on is small enough, you can cut away the mold and use the cheese ASAP.
- If there is too much mold on the cheese (more than an inch in size), it means that the bacteria have most likely already spread across the surface of the cheese and could be hazardous. Rather throw the cheese away.
Other, less obvious signs that the hard cheese has gone bad includes discoloration of the cheese (either becoming pale or too dark), a change in texture (for example unaged cheddar becoming hard and crumbly) and any odors that smells sour and rancid.
Is It OK to Use Expired Hard Cheese?
You can have a look at the cheese once it has reached its expiry date to determine whether or not it shows any signs of going bad. If there aren’t any, make sure to use the cheese as soon as possible.
However, if the cheese has shown any signs of spoilage, it should be discarded immediately.
There are tons of very dangerous bacteria growing on cheese including E.coli, Salmonella, Brucella and Listeria.
These all cause food poisoning which everyone knows, is at best extremely unpleasant and could even be deadly.
Can you freeze hard cheese?
You can freeze hard cheese to prolong its shelf life; however, it will massively affect the texture and flavor of the cheese. The texture will become crumbly and you will not be able to grate it again. The flavor will be diluted once thawed due to all the ice crystals melting.
It is best to keep the hard cheese in the refrigerator and use it before its expiry date.