How Long Mozzarella Cheese Lasts in the Refrigerator

Fresh Mozzarella Lasts 3 to 7 Days; Packaged Mozzarella Lasts 3 to 8 Weeks

How long your mozzarella stays fresh depends almost entirely on what kind you bought. Fresh mozzarella—the soft, delicate kind sold in water or whey—will last about 3 to 7 days once you open it. Packaged mozzarella—the firmer blocks or shreds you find vacuum-sealed—will last 3 to 8 weeks unopened, and 1 to 2 weeks after you open the package. Unopened packages sometimes carry a "use by" date that extends several months out, but that's a manufacturer's estimate for sealed conditions; once air reaches the cheese, the clock moves faster.

The difference comes down to moisture and how the cheese is packaged. Fresh mozzarella contains far more water, which bacteria love. Packaged mozzarella has less water and often sits in a protective brine or vacuum seal that slows spoilage. Neither type will last forever, and both will show clear signs when they've gone bad—so you don't have to guess.

Key Takeaways

• Fresh mozzarella in water or whey lasts 3 to 7 days in the coldest part of your refrigerator, usually the back of a shelf or the cheese drawer.
• Packaged mozzarella blocks or shreds last 3 to 8 weeks unopened and 1 to 2 weeks after opening, depending on how well you reseal the package.
• Mozzarella that smells sour, feels slimy, or shows visible mold has spoiled and should be thrown out immediately.
• Storing mozzarella in an airtight container or resealable bag slows moisture loss and mold growth, extending shelf life by several days.
• Freezing mozzarella changes its texture permanently, making it grainy and crumbly, so it works only for cooking, not for eating fresh.

Why Fresh Mozzarella Spoils Faster

Fresh mozzarella is made by heating curds and stretching them—a process that leaves the cheese soft and full of water. That water is what makes it tender and mild, but it's also what makes it vulnerable. Bacteria and mold thrive in moisture, so fresh mozzarella begins to break down the moment you open the container. The liquid it sits in—usually water or whey—slows that breakdown, but it doesn't stop it.

The moment you remove fresh mozzarella from its liquid or expose it to air, you're speeding up spoilage. If you drain the liquid to use the cheese, transfer what you don't use to an airtight container with a little of the original liquid, or cover it tightly with plastic wrap. This keeps air and new bacteria from reaching the surface. Even with these steps, plan to use it within a week.

How to Store Packaged Mozzarella Correctly

Packaged mozzarella—whether blocks, slices, or shreds—comes in a sealed wrapper designed to keep air and moisture out. Leave it sealed until you're ready to use it. Once you open the package, the cheese is exposed to air and your refrigerator's humidity, both of which cause it to dry out and develop mold.

After opening, transfer the mozzarella to an airtight container or a resealable plastic bag, pressing out as much air as possible before sealing. If the original package has a resealable top, you can use that, but make sure it closes completely. Store it in the coldest part of your refrigerator—usually the back of a shelf or a dedicated cheese drawer—where the temperature stays steady around 35°F (1.7°C). Avoid the door, where temperature fluctuates every time you open it.

Shredded mozzarella is more vulnerable than blocks because shredding increases the surface area exposed to air. Once opened, shredded mozzarella lasts about 1 week if kept sealed; blocks last closer to 2 weeks. If you notice the shreds clumping together or developing a hard, dried edge, it's still safe to cook with, but it won't melt as smoothly.

Signs That Mozzarella Has Spoiled

Mozzarella that has gone bad will show one or more of these clear signs: a sour or off smell (not the mild, milky smell of fresh cheese), a slimy or sticky texture, visible mold (usually white, green, or blue), or discoloration beyond the normal pale white or cream color. If the cheese has been sitting in liquid and that liquid has turned cloudy or developed a sour smell, the cheese inside has likely spoiled too.

Trust your senses. If you're unsure whether it smells right, it probably doesn't. Mozzarella that's beginning to spoil won't make you sick immediately, but it will taste off and may cause digestive upset. It's not worth the risk—throw it out and buy fresh. The cost of a new package is far less than the cost of food poisoning.

Temperature and Humidity Matter More Than You Think

Mozzarella lasts longest when your refrigerator holds a steady temperature between 32°F and 40°F (0°C to 4°C), with moderate humidity. If your fridge is warmer than 40°F, mozzarella will spoil faster—sometimes by several days. If it's colder than 32°F, the cheese may freeze slightly at the edges, which changes its texture when it thaws.

Humidity also plays a role. A refrigerator that's too dry will cause mozzarella to shrink and develop a hard rind; one that's too humid will encourage mold. Most refrigerators regulate humidity automatically, but if yours has a humidity control dial (usually in the crisper drawer), keep it set to medium. Never store mozzarella directly next to items with strong odors—onions, garlic, or fish—because cheese absorbs those smells easily.

Can You Freeze Mozzarella, and Should You?

You can freeze mozzarella, but the results are not ideal. Freezing breaks down the protein structure of the cheese, causing it to become grainy and crumbly when thawed. Fresh mozzarella becomes almost unusable for eating fresh or for making caprese salad. Packaged mozzarella holds up slightly better and can work in cooked dishes like lasagna or pizza, where the texture change is less noticeable.

If you do freeze mozzarella, wrap it tightly in plastic wrap or place it in a freezer bag with as much air removed as possible. It will last 3 to 6 months frozen, but use it only for cooking. Thaw it in the refrigerator overnight before using. For most home cooks, it's better to buy smaller packages of mozzarella more often than to freeze it and accept the texture loss.

Storage Tips for Different Mozzarella Types

Fresh mozzarella balls (bocconcini or ciliegine): Store in their original brine or whey in an airtight container. If you've removed them from liquid, cover them completely with fresh, cool water and change the water every 2 to 3 days. Lasts 3 to 7 days.

Fresh mozzarella logs or braids: Keep in their original packaging or transfer to an airtight container with a small amount of the original liquid. Lasts 3 to 7 days.

Packaged mozzarella blocks: Store in an airtight container or resealable bag after opening. Lasts 1 to 2 weeks after opening.

Shredded mozzarella: Keep sealed in its original package or transfer to a resealable bag. Lasts about 1 week after opening. If clumping occurs, break it apart with a fork before using.

Smoked mozzarella: Treat like packaged mozzarella. The smoking process adds some preservation, but it still needs to be sealed and refrigerated. Lasts 2 to 3 weeks after opening.

Frequently Asked Questions

Can I eat mozzarella that's been left out on the counter for a few hours?

Fresh mozzarella should not sit at room temperature for more than 2 hours. Packaged mozzarella can handle 2 to 4 hours depending on room temperature. If it's been longer than that, or if the room was warm, throw it out. Bacteria multiply rapidly at room temperature, and you won't always see or smell the problem.

Why does my packaged mozzarella get hard and crumbly?

Packaged mozzarella dries out when exposed to air or stored in a very cold part of the fridge. Make sure you're sealing it tightly after each use and storing it in the coldest part of your fridge—not the freezer. If it's already hard, it's still safe to cook with, but it won't melt smoothly.

Is the liquid in fresh mozzarella packaging safe to drink or cook with?

Yes, the liquid is safe and often used in cooking. Some people save it to make ricotta or use it in pasta water. However, once the mozzarella has spoiled, the liquid has spoiled too, so discard both together.

How do I know if unopened mozzarella has gone bad?

Check the package for swelling, which indicates gas production from bacteria. Look at the liquid inside—if it's cloudy or discolored, the cheese has likely spoiled. If the package feels warm or has been stored above 40°F for an extended time, assume it's unsafe and don't open it.

Does mozzarella last longer if I store it in the coldest part of the fridge?

Yes, but only slightly, and only if the coldest part stays above 32°F. Storing mozzarella at the very back of the fridge or in a dedicated cheese drawer can add a few days to its life. Avoid the freezer compartment unless you're intentionally freezing it for cooking.