Left Your Pasta Sauce Out Overnight? (Here’s How to Know if It’s Safe)


Have you ever left your pasta and sauce out overnight and wondered if it’s ok to eat? You’re not alone in trying to decide whether it’s fine or if it’s best to just toss it in the garbage.

Do not eat pasta sauce if it has been left out overnight. Pasta sauce will grow bacteria if it is not refrigerated or stored properly. If a person eats pasta sauce that is left out overnight, they will get food poisoning, which will cause symptoms such as an upset stomach and possibly a fever.

Spaghetti sauce in a mason jar with tomatoes and olive oil on a wooden table,
Spaghetti sauce in a mason jar with tomatoes and olive oil on a wooden table.

I called Revere Health and talked to their nutritionists about the problems associated with leaving pasta sauce out overnight and I have recorded their response below. Read on to learn what types of pasta sauces are more dangerous to eat if left out overnight and how to preserve your pasta sauce.

Does Pasta Sauce need to be Refrigerated?

Pasta sauce is bought off of shelves in the store. They are kept at room temperature and probably when it was being transported the pasta sauce probably reached high levels of heat inside of the truck they were in. Therefore, does pasta sauce even need to be refrigerated at all?

That is a good question. Pasta sauce that has been bought from the store has been canned. They have been created to be in an air-tight container that will not allow any outside elements to get into your sauce. With all of these conditions, they are able to last at room temperature without any issues. Therefore, if you just bought a can of pasta sauce and have not opened it yet, then your pasta sauce is fine.

On the other hand, if you opened the pasta sauce already, then you should not eat it if it has been left out overnight. This is dangerous because other elements that would have been eliminated in the cold fridge get in and spoil your pasta.

If this is homemade pasta, you should try and keep it in the fridge. If you can make your own pasta, though, it should be safe. If you just made your pasta, though, and stuck it in a ziplock bag or a Tupperware container, then you will need to refrigerate your pasta sauce to keep it safe to consume.

What Happens to Pasta Sauce Left out Overnight

When your pasta sauce is in an air-tight can. Nothing can get into your tomato sauce. It is protected from all other elements. The second you unscrew the lid, though, your pasta sauce is open for attack. Small critters called microbes can crawl in and eat your tomato sauce.

Bubbling hot tomato sauce for pasta, cooking in pan with wooden spatula.
Bubbling hot tomato sauce for pasta, cooking in pan with wooden spatula.

When a microbe finds your pasta sauce, they eat it and this is what causes your pasta sauce to rot. A common type of microbe that eats your pasta sauce is bacteria.

Other microbes that can get into your pasta sauce are mold and yeast. These will grow in your pasta sauce. Eating these organisms can make you very very sick. This is why it is so important not to eat spoiled pasta sauce.

What if one of these microorganisms gets in before your pasta sauce is canned though? One good thing about pasta sauce is that when it is canned it is boiled at an extremely high temperature. This kills all of the microbes and makes the food safe to eat.

Once your pasta sauce is rotten from bacteria, mold, or yeast growth, you cannot kill the bacteria, mold, or yeast without killing your pasta sauce. Therefore, make sure that you do the preventative work necessary to keep your pasta sauce safe from microbes or you will not be able to eat it.

Can Different Types of Pasta Sauce be Left out Overnight

There are lots of different types of pasta sauce, and some can fight the elements better than others. 

Tomato Sauce

Tomato sauce is highly acidic and canned tomato sauce has a pH range of 3.5-4.7. The high pH level and acidic nature of tomato sauce cause tomato sauce to last much much longer outside of the fridge. Bacteria tend not to survive as long with high acid levels. 

You should check whether or not bicarbonate of soda in your tomato sauce, though. Bicarbonate of soda removes the acid levels in tomato sauce, which inspires a much higher bacteria growth rate.

Overall, I would not eat tomato sauce that has been left out for over 4 hours, but if you do a sniff test and it smells all right, then you can give it a go. 

Alfredo Sauce

Alfredo sauce will not last as long as tomato sauce. Alfredo sauce does not have the acidic nature of tomato sauce, so bacteria will attack it much quicker. 

The creamy nature of Alfredo sauce helps bacteria to grow and spoil your sauce. The rule of thumb is if you leave your Alfredo sauce out for more than four hours, it is no longer safe to eat. Therefore, take care to put away your Alfredo sauce. 

Pesto Sauce 

Pesto sauce is the worst at staying at room temperature. Pesto sauce should not be eaten if it is left outside of the fridge for more than two hours. 

If you left it in the car and were wondering if the cold weather could, your pesto sauce check whether the temperature has been under 40 degrees Fahrenheit. Pesto sauce starts to spoil at temperatures above 40 degrees. 

Proper Storage of Pasta Sauce

What is the best way to store your pasta sauce to keep it from spoiling? There are several options for you.

To begin with, when you first get your pasta sauce from the store, you do not have to refrigerate it. When your pasta sauce is in the can it is safe from all bacteria. Therefore, you can keep it in the cupboard if you wish. Either way, though, try and keep your pasta sauce in a dry and cool area to keep it from any sort of pollution.

Jars of sauce, olives, pickles, and vegetables.

Once you have opened your pasta sauce, you can put it in the fridge. This will keep your pasta sauce anywhere from 5-6 days. You will then have to eat your pasta sauce fast, but it is better than leaving it out, which will cause your sauce to spoil in a matter of hours.

Another great option is to keep your pasta sauce in the freezer. In the freezer, your pasta sauce will last around 6 months. This is a long time and is a great option if your family eats a lot of pasta sauce. All you have to do when you are ready to use it is boil your pasta on the stove. If you store your pasta in the freezer, though, make sure that your pasta does not get freezer burn, because that will ruin the taste.

How to tell if your Pasta Sauce has Gone Bad

Well, your pasta sauce has been left out and you want to check for yourself whether or not it has gone bad. How can you tell if your pasta sauce has gone bad or not? There are several different ways to tell. It is different depending on what kind of pasta sauce you have.

To begin with, if you have a tomato-based sauce, you can tell by darkening. If the color is getting darker, then your sauce starts to rot. Also, if you notice that the paste is getting thicker, that is not a good sign for your pasta sauce.

If you have milk-based pasta, then you can check for whether the pasta has gone bad the same way you check the milk. For instance, smell is a large factor. If your sauce smells sour then it is quite possibly rotten. The color is darker and also an indicator that your pasta sauce is rotten.

Another way to tell if your pasta sauce is rotten is if you see mold growth. If you see any mold growth at all on your pasta sauce, throw it away. It means that the microbes have gotten to your pasta sauce first and it will no longer be edible.

Is Pasta Sauce left out Overnight in an Insulated Bag Okay?

Are you planning on leaving your pasta sauce in an insulated bag so you can take your pasta sauce on the road? If you are planning on doing this, you might be wondering how long you can travel with your pasta sauce in an insulated bag. There are a lot of factors that go into that, but I can help you learn how to decide whether you are prepared to take your pasta sauce on tour.

Man in checkered shirt holding insulated thermal  bag
Man in checkered shirt holding insulated thermal bag.

If you are only going for a 4-6 hour drive, then you can put it in an insulated bag and it should be alright. If you go for longer, then you will want ice.

You want your pasta sauce to stay below 40 degrees Fahrenheit. Therefore, if you are keeping your pasta sauce in an insulated bag for a long period of time, you will want to replace the ice in your bag often enough to keep your pasta cold enough.

To keep your pasta sauced iced, you will want a waterproof insulated bag because the ice will melt and damage your bag. Therefore, before you leave your pasta sauce in an insulated bag, pack it with ice in a waterproof insulated bag.

How Sick will I be if I Eat Pasta Sauce that has been Left Out Overnight?

Now your pasta sauce has been left out for longer than suggested, but it looks so good and you don’t want it to go to waste. Therefore, you decide to eat your pasta sauce like the risk-taker you are, but you start feeling sick. How sick are you going to get?

Italian pasta bolognese with beef, basil, and parmesan cheese.
Italian pasta bolognese with beef, basil, and parmesan cheese.

Food poisoning is not a fun thing to have. There are many symptoms that come with food poisoning. The first symptom is a pain in your abdomen or rectum. This one is not fun and you might want some ibuprofen for that one.

You will often get a fever with food poisoning that will cause chills, dizziness, and fatigue. Resting will help with the fever and keep it from getting too much worse.

You might also feel lightheaded and lose your appetite. This can happen because of the vomiting, stomach cramps, flatulence, and bloating that come from food poisoning.

Be careful if you are throwing up or having heavy diarrhea to make sure that you are drinking plenty of water. If you do not have enough water, you can get dehydration. This can be deadly to humans and is one of the more dangerous symptoms of food poisoning.

What can you do with your Spoiled Pasta Sauce?

Well, your pasta is spoiled and you do not want to risk getting sick by eating it. What do you do with the pasta now? It seems like a waste to just throw it away, but are there any other options? There are a few other options for you.

Spaghetti bolognese with parmesan cheese on a white plate on black table.
Spaghetti bolognese with parmesan cheese on a white plate on black table.

To begin, you can create a compost pile. If you have a back yard, you can buy a barrel or section of a piece of ground in your backyard where you can throw all of your wasted food at it. This will allow your pasta sauce to break down into rich soil.

If you have a garden, compost is great for your vegetables. The composition is rich with nutrients and will help your vegetables to grow to be stronger and more delicious.

You can also recycle the jar you got your pasta sauce out of if you really want to save the environment. This will help the waste crisis that the United States is in right now. To recycle the jar, you will need to wash out the rest of the pasta sauce so it is completely clean and then you can put it in your regular recycling pick-up.

Anna Silver

Anna Silver is the principal creator of CookForFolks.com, a website dedicated to new go-to original recipes. Inspired by her grandmother’s love of cooking, Anna has a passion for treating the people in her life to delicious homemade food and loves to share her family recipes with the rest of the world.

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