When you get your hands on a nice slice or block of cheese, it's perfectly reasonable to think about how to extend its shelf life so you can use it as long as possible. Freezing is a well-established method of preserving food for longer, but before you put the cheese in the freezer, it's important to know what type of cheese you should store.
Each time a food is placed in the placed in a freezer, its water content is converted into ice crystals, which increases its volume by 9%. And when it thaws, it contracts, so these volume changes affect its molecular structure. Fresh, soft cheeses such as ricotta and the camembert have a high moisture content, so they change from creamy to crumbly. This also applies to low pH cheeses such as cream cheese. During storage, the fat also separates from the other ingredients, so the cheese becomes oily or chunky when it thaws.
What about harder cheeses?
Semi-hard and hard cheeses such as gruyère, the Parmesan and the cheddar they can withstand freezing better. Processed cheeses also withstand freezing well thanks to stabilisers added by cheese makers, and the pasteurisation and standardisation of the milk used also contributes to better resistance to freezing. However, don't expect the cheese to retain its pre-freezing characteristics. For example, cheddar cheese will not slice as well as it used to. Since freezing inactivates the enzymes and live cultures that promote further ripening, they will also lose their intensity.
Think about what form you'll need the cheese in later
These changes in quality make it important to know how you plan to use the cheese later. This can help you decide whether it is worth freezing it at all. If you are using it for cooking purposes, it is safe to store hard, semi-hard and processed cheeses in the freezer, ideally in their original, unopened packaging. The change in texture will be less noticeable for these if you're making a three-cheese mac and cheese, for example.
When packing leftover cheese, it's a good idea to divide it into portions, then wrap them in plastic and then aluminium foil to protect them from freezer burn. Not only is it easier to defrost later if the cheese is cut into smaller pieces, but they also freeze more quickly, which means that the ice crystals formed are smaller and less damaging to the structure and texture of the food. Grated or shredded cheese, on the other hand, should be stored in a package with a resealable lid. Let excess air out of the bag before sealing to keep the cheese good for up to six months.
Thaw the frozen cheese gradually so that its moisture is evenly distributed, rather than creating wet patches. To achieve this, place it on a plate while still wrapped and leave it in the fridge for 12 hours to thaw.
