Does String Cheese Need to Be Refrigerated? How Long Does It Last?

String cheese is a perfect snack on the go. Does string cheese need to be refrigerated? How long does string cheese last before going bad?

String cheese does need to be refrigerated. When kept in the refrigerator, an unopened package of string cheese will last up to one week. An opened package of string cheese stored in the fridge will last 4-5 days.

When not refrigerated, an unopened package of string cheese lasts for about 8-10 hours before it goes bad.

String cheese is simply Mozzarella cheese, and Mozzarella cheese needs to be refrigerated, or it goes bad in just a few hours.

Read on to learn more about properly storing opened and unopened packages of string cheese and how long it lasts before going bad.

Does String Cheese Need to Be Refrigerated?

An unopened pack of string cheese stored inside the fridge can last up to one week. An opened pack stored inside the fridge will last up to five days.

If you’re putting it in your kid’s lunchbox or putting it in your purse for a snack, it will stay good for about 8-10 hours, unrefrigerated, provided it is kept unopened.

Everyone likes eating string cheese. String cheese can come from different kinds of cheese, but string cheese usually comes from mozzarella that’s low-moisture. They are commonly packaged in snack-size servings and are sometimes called cheese sticks.

Sometimes, you can get string cheese that contains cheddar. They are cylindrical and about six inches long. Frank Baker invented ‘string cheese’ in 1976, and it has since become one of the most popular snacks in the US.

You have to store cheese inside the fridge. Mozzarella, the main ingredient of most string cheese, is best kept in the fridge until ready to be consumed.

Refer to these guidelines to know how long the string cheese will last:

  • Unopened pack, refrigerated: 1 week
  • Opened pack, refrigerated: 4-5 days
  • Unopened pack, room temperature: 8-10 hours
  • Opened pack, room temperature: 2 hours
Does string cheese need to be refrigerated

Tips on Properly Storing Unopened and Opened String Cheese

How long does string cheese last? String cheese can last up to one week if it is refrigerated and unopened. To extend its shelf-life, below are the things you can do:

Unopened Pack of String Cheese

  1. It is better to store an unopened string cheese inside the fridge until you’re ready to consume it.
  2. If you have doubts about the freshness of your string cheese, smell it, and examine closely. When it smells bad or sour, discard it. If you see mold, it is also best to throw it out.
  3. If you notice that your package of string cheese has gone a bit past the sell-by or best by date stamped on it, don’t fret. String cheese will be good for a week, even after their sell-by or best by date.
  4. To make string cheese last longer, you can freeze it. It is best to keep the string cheese in a heavy-duty freezer bag or container.
  5. Frozen string cheese can last for up to eight months in the freezer. Ensure that it’s stored properly. Make sure you have a constant temperature of 0°F.

Opened Pack of String Cheese

  1. If you have opened up your package of string cheese, keep it refrigerated at all times.
  2. If you open up a string cheese package, you need to store it properly to last five to seven days in the refrigerator.
  3. Consume your stick of string cheese upon opening. Do not leave leftovers. Once you open it, it becomes exposed to bacteria that can grow on the cheese. This may cause foodborne illnesses.

How Is String Cheese Made Stringy?

Have you ever wondered why your favorite string cheese snack is stringy? How did it get stringy?

As stated earlier, most of the string cheese you buy in supermarkets usually comes from mozzarella. It’s basically mozzarella with a twist. On the other hand, mozzarella comes from a combination of milk, culture, and rennet. Experts use rennet, a set of enzymes to separate the milk. They also often used this enzyme in making most cheese varieties.

The production of mozzarella involves heating the curds to 140 °F. Heating causes the milk’s proteins to align together, and the cheese becomes stretchy. Once stretchy, you can mold it into balls or blocks like the ones available in the supermarkets.

Making string cheese is slightly different. Once stretchy, instead of molding it, it is divided into strips and then continuously stretched. This was first done by Frank Baker, a well-known cheesemaker from Wisconsin.

So, mozzarella and string cheese are actually the same cheese. But string cheese is very much different from mozzarella in its storage requirements.

While mozzarella is stored in brine or water to keep it fresh, string cheese needs to be dried out to lose moisture. Of all the cheese, mozzarella is the only one that has stringy properties, and so it’s perfect for making string cheese.

So string cheese is actually mozzarella that has been stretched a lot.

Other Fun Facts About String Cheese

  • Because string cheese is so awesome, it actually has a day dedicated to it. Yes, September 20 was named National String Cheese Day! Galbani Cheese founded it in 2017.
  • String cheese is an excellent source of calcium. It gives you 20% of the daily recommended value.
  • This all-time favorite snack is packed with protein that has only 70 to 80 calories.
  • It is convenient and handy and can be packed easily in lunchboxes. It is not messy and can be eaten anytime, anywhere.

Does string cheese need to be refrigerated? Does string cheese go bad? String cheese does need to be refrigerated. When kept in the refrigerator, an unopened package of string cheese will last up to one week. An opened package of string cheese stored in the fridge will last 4-5 days.

Next, let’s discuss how you can properly store opened and unopened packs of string cheese below.

How to Make Your Own Mozzarella for String Cheese

Remember, the secret to making string cheese is stretching the cheese. What’s amazing is that it can be done at home. To start with, you’ll need to make mozzarella first.

does string cheese have to be refrigerated

Here’s a quick and easy recipe for mozzarella. It’s simple enough for everyone.

What You Need:

  • Thermometer
  • A pot that can hold a gallon of milk with mixing room
  • Colander
  • Kitchen knife
  • Metal slotted spoon
  • Microwave-safe bowl or small pot
  • A gallon of milk (cow’s milk is fine but for a richer taste, use goat’s milk)
  • 1 and ¼ cup of water
  • ¼ tablet rennet
  • A bowl of water put in the fridge
  • A bowl of water put in the freezer


  1. Dissolve your ¼ tablet of rennet in ¼ cup of water. Do not discard the rest of the tablet. It can be properly stored in the freezer.
  2. Pour your gallon of milk in your large pot and stir, stir, stir with a slotted spoon while heating. The temperature should be between 88 to 90°F.
  3. Remove your pot from heat. Stir in your rennet mixture slowly with your slotted spoon. This will take about 30 seconds.
  4. Cover your pot and let it stand for five minutes. After that, your curd should be soft and custardy. It should be separated evenly between the curd and the whey. The curd is the solid part, and the whey is the liquid part. The curd should not be too soft. If it is, add a few more minutes to the standing time.
  5. Now, you’ll need to cut the curd. Use a long knife so that it reaches all the way to the bottom of the pot.
  6. Return your pot over low heat and heat it back up again, continuously stirring the curd, still using your slotted spoon. Heat the raw milk to 88 °F. If you’re using pasteurized milk, you should heat it to 90°F.
  7. Remove the pot from the stove and continue to stir for about four to five minutes. If you want your cheese to be soft, you should stir minimally.
  8. Drain the whey from the pot.
  9. Stretch the curds.
  10. Mold your cheese now. You may make mozzarella balls or logs or sticks.
  11. Let your cheese cool. Please place it in your bowl of refrigerated water and leave there for 15 to 20 minutes.
  12. Transfer them to your bowl of water inside the freezer for about 5 minutes. Please do not skip this step as it is important to keep it from becoming grainy.

Stretching the Curds

Stretching the curds is entirely a whole new process. So, if you’re stretching a big batch of curds, it’s best to divide the batch. Here’s how to stretch your curds using a stovetop.

  1. Fill a pot with water and heat to 185°F.
  2. Strain the curds using a colander, working them towards the center and draining the whey.
  3. Dip the whole colander with the curds inside in hot water a few times. Use your slotted spoon to fold the curds to the center. Keep doing this until they become stretchy. It will start to go stretchy when the temperature reaches 160 to 170°F.
  4. Take your curd from the colander and stretch it out. It should stretch easily. If it doesn’t, put it back in hot water.
  5. Keep stretching the curds until they become shiny.

How to Make String Cheese from Mozzarella?

Homemade string cheese is always a good option for a healthy snack. And, what makes it even better is that you know what exactly is in your cheese.

The secret to good homemade string cheese is to stretch your mozzarella properly, over and over again. Here’s how to make string cheese from the mozzarella recipe above.

does string cheese go bad
  1. Check that the temperature of the curd is around 170°F.
  2. Ball up your curd and in the middle, poke a hole so that it looks sort of like a doughnut.
  3. Stretch the doughnut-shaped curd so that it looks like it is looped.
  4. Fold your loop in half so that it looks like you have four large strings, and then stretch it again.
  5. Keep doing the folding and stretching again and again.
  6. It would be best if you kept stretching and folding again and again. You’ll end up with thin ropes of cheese.
  7. Stretch out your cheese so that you will have a roll of ½ inch in diameter.
  8. Cut into sticks that are about 6 inches long.
  9. You may twist the sticks or keep them as they are. Seal the ends together by pinching them.
  10. Leave the cheese sticks in a cool dry place.
  11. Store the string cheese either separately or together. Make sure that the container is tightly sealed so that they do not get mold.

Conclusion – Does String Cheese Need to Be Refrigerated?

Does string cheese have to be refrigerated? String cheese is mozzarella cheese, so you do have to refrigerate it, even if it is unopened.

An unopened pack of string cheese stored inside the fridge can last up to one week. Meanwhile, an opened pack of string cheese can last up to five days when stored inside the fridge.

Refer to these guidelines to know how long the string cheese will last:

  • Unopened pack, refrigerated: 1 week
  • Opened pack, refrigerated: 4-5 days
  • Unopened pack, room temperature: 8-10 hours
  • Opened pack, room temperature: 2 hours

In the US alone, string cheese is one of the best-selling cheese. You can make homemade string cheese easily with the recipe given above. Just remember to keep it in the fridge so that it stays fresh for longer.

Related reading:

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How Long Does Soup Last in the Fridge? [Chicken Soup, Vegetable Soup, and More]

Mold on Cream Cheese – Is It Safe? What If You Eat It?