The answer to why cheese hardens in the refrigerator is that the moisture inside the cheese gradually escapes into the cold, dry fridge air over time. Products like white cheese that are stored uncovered or loosely wrapped harden as their surfaces dry out and lose water, and start crusting from the edges.
The inside of a refrigerator is a relatively dry environment, as well as cold, in order to preserve food. When cheese is left exposed in this environment, the moisture on its surface slowly evaporates into the air and the texture gradually stiffens. Since moisture loss is especially pronounced on the outer surface of cheese, the edges dry first, then the hardness advances toward the interior. Mature cheeses with low fat and moisture content undergo this change more quickly, while fresh, moist, and brined cheeses can retain their moisture a little longer. Temperature fluctuations and a fridge whose door is opened frequently also speed up the drying.
Why Does Cheese Harden in the Refrigerator, and How Can It Be Prevented?
Preventing cheese from hardening is largely about preventing moisture loss. When the following measures are applied together, cheese stays soft for longer.
- Cheese should be wrapped tightly to cut off contact with air, or stored in a closed container.
- Brined cheeses should be kept in their own brine or in slightly salted water so they don't dry out.
- Cheese should be stored on the more stable interior shelves of the refrigerator rather than near the door, where the temperature varies the most.
- Once opened, cheese should be consumed as soon as possible and not left exposed for long periods.
- If the surface of the cheese has started to dry, it can be balanced out by covering it with a damp cloth.
What Are the Common Mistakes Made When Storing Cheese?
Certain mistakes made when storing cheese noticeably speed up hardening.
- Leaving cheese uncovered on an open plate in the refrigerator causes it to lose moisture rapidly.
- Draining the brine from brined cheese and storing it dry causes its surface to harden quickly.
- Keeping cheese on the door shelf, where the temperature keeps changing, speeds up drying.
- Leaving a large piece exposed for a long time to be consumed little by little causes the remaining portion to harden.
Can Hardened Cheese Be Softened Again?
Cheese that has hardened solely due to moisture loss, with no signs of spoilage, can usually still be used. Brined cheeses can soften somewhat when soaked in warm salted water for a while. Grating hardened cheese and using it in dishes, pastries, or gratins is also a practical solution, since the cheese regains its texture as it melts with heat. However, if there is mold, a sour smell, or discoloration on the cheese, this is no longer a sign of moisture loss but of spoilage, and it should not be eaten.
Which Cheeses Harden Faster?
Mature cheeses with low moisture and fat content tend to harden faster when left exposed, because the amount of water they have left to lose is already limited and their surfaces crust over quickly. Fresh, moist cheeses kept in brine, on the other hand, can retain their moisture for longer. For this reason, choosing the storage method according to the type of cheese is an important detail in delaying hardening.
In summary, the answer to why cheese hardens in the refrigerator is that the cheese loses its moisture to the cold, dry fridge air. Wrapping cheese so it doesn't contact air, keeping brined varieties in their brine, and storing it on a stable shelf largely prevent hardening. Grating hardened cheese and using it in cooked dishes, meanwhile, both prevents waste and adds to the flavor.