Does String Cheese Go Bad?

You’ve added some string cheese to your child’s school lunch box, and they forgot to eat it. Now it’s supper time, and you’re not quite sure if the cheese is still okay to eat after a whole day in your child’s rucksack. Does string cheese go bad if not refrigerated?

Or maybe you opened a package of string cheese a few days ago, and you’re wondering for how long will the cheese stay fresh and tasty. Or if you can freeze the leftovers instead of desperately trying to fit them into your meals.

If some of these thoughts sound familiar, this article is for you. In it, we go through storage, freezing, shelf life, and going bad of string cheese. If that sounds interesting, read on.

Bucky Badget String Cheese
Image used under Creative Commons from k.steudel

How to Store String Cheese

Like almost all dairy products, you should store string cheese in the fridge.

Once you open the package, make sure you seal it tightly before putting it back into storage. If that’s not possible, transfer the package to a freezer bag and squeeze as much air out before you seal it.

That’s important for two reasons. First, cheese likes to pick up odors, and you definitely don’t want string cheese smelling like sausage. Second, a good seal prevents air pockets from forming around the cheese and from drying it out.

If you’re adding string cheese as a snack to your child’s lunch box, putting it in a separate container or freezer bag for additional protection would be ideal. But often that’s not a realistic scenario, so the cheese has to sit with other items, and that’s quite okay too. Just make sure it doesn’t sit with anything moist like cut tomatoes, as the cheese will taste pretty bad after an hour or two.

Also, don’t let the cheese to sit on the counter for longer than it’s necessary. Semi-soft cheese like string cheese degrades quite quickly at room temperature. So changes in taste are quite possible if it’s left sitting out for too long. And you definitely don’t want to add cheese that’s already starting to dry out to your kid’s lunch.

String cheese closeup
String cheese closeup (credit: AJC1)

Can You Freeze String Cheese?

Freezing cheese, in general, is an object of an ongoing debate. If you scoured the Internet for opinions, you would find as many fans of freezing cheeses as people advising against it. With such a situation in mind, the best answer to this question is: you tell me.

Generally, the firmer the cheese, the better it freezes. So yes, you can freeze string cheese and the results shouldn’t be that bad. Please note, however, that the freezing and thawing process will make the cheese more crumbly.

Therefore, if you need it for a dish where you melt it anyway, that’s not an issue at all. But if you want to add a stick or two to lunch, the results may vary. In short, it’s best if you freeze some as a test and see how it turns out.

When it comes to how to freeze string cheese, if it’s in the original packaging and unopened, just throw it into the freezer. If you already opened the package, add a layer of protection by transferring it into a freezer bag. Remember to squeeze as much air out of the bag before you seal it.


If you only need a stick or two at the time, you can repack the cheese into several freezer bags for even easier thawing.

Once you need the cheese, just chuck it in the fridge the night before.

String cheese in progress
Image used under Creative Commons from Quinn Dombrowski

How Long Does String Cheese Last

String cheese comes with a date on the label. In most cases, it’s a sell-by or use-by date, but it’s not uncommon for it to have a best-by date. No matter which variety it is, you should know that generally, string cheese has a pretty long shelf life of at least a few months. Unlike buttermilk or half and half, that usually go bad soon after the date on the label, it can last for even 2 or 3 weeks more in good quality.

Once you open the package, try to finish the cheese within around 7 days for best quality. Of course, if you keep good care of it, it will last longer. Please note that there’s no way of saying how long will it last exactly. That depends on the storage conditions, the quality of the cheese, and its ingredients.

When it comes to the scenario I described at the beginning of the article, that is keeping string cheese for the whole day in a lunch box, it should be quite okay. String cheese usually has some preservatives and thus doesn’t go bad or ruined after a few hours in the lunch box.

While the quality probably won’t be top-notch anymore, it should be good enough to eat. It’s really up to you to decide. But I definitely wouldn’t put it back to the fridge to add it to lunch the next day. Either use it now or discard it.

String cheese (unopened)Date on the label + 2 – 3 weeks
String cheese (opened)1 week

Please note that the periods above are estimates and for best quality.

Pizza Bread with Polly-O string cheese
Pizza Bread with Polly-O string cheese (credit: ChrisGampat)

How to Tell if String Cheese has Gone Bad?

First off, look for the usual signs of spoilage, such as odd aroma, any organic growths or bluish-grey specks on the surface of the cheese. If any of these are present, throw it out.

If you already store it for much longer than you should, i.e., opened for like 3 weeks or unopened for 2 months past the date on the label, err on the side of caution and get rid of it too.

Given that everything about the cheese seems to be okay give it a taste, and based on that decide if it’s good enough in terms of quality. If it’s not, cut your losses and throw it out. And definitely don’t try to add it to your kid’s lunch. If you want to sneak in some dairy to your child’s diet, using old cheese is not the way to go.