How Long Can Overnight Oats Last?

The world is a dangerous place, and we want you to be safe. One of the first steps in being safe is ensuring that your food is kept away from any harmful bacteria that are looking for a tasty meal.

With so many foods to choose from, it can be difficult to know how long each type lasts before spoiling.

This is why we’ve compiled some important information for you about exactly Overnight Oats and how long they last!


Does Overnight Oats Get Spoiled?

Overnight oats do not get spoiled as quickly as other foods because they are stored in mason jars with lids that create a seal to keep all the air out. Most recipes for overnight oats also call for the addition of an acidic fruit like strawberries, blueberries, or mango.

The acidity in these fruits creates some airtight plastic-like properties that help keep the mason jar closed. Eating an ‘old’ batch of overnight oats usually tastes a little sour but still good.

To be on the safe side, it’s always a good idea to make sure those jars get opened and checked every few weeks just to make sure nothing has gone bad.

How Long Can Overnight Oats Last?

The duration of usage for overnight oats depends on how long you make a batch, the type of oats and fruit you use, and how many jars you store in your pantry. An average recipe would make a batch that lasts between 2-3 days in a mason jar with an airtight lid. If you eat sugar-free overnight oats, they usually last even longer.

For those that are used to eating gluten-free foods, fruit-only overnight oats are the best because they will last the longest before spoiling (although don’t eat them all at once!!). The longer you keep those jars in your pantry, the longer they will last.

How Long Can Overnight Oats Last
How Long Can Overnight Oats Last

How Long Is Too Long For Overnight Oats?

The answer to this is up to every individual, but in general, most people wouldn’t want their overnight oats to last more than 4-5 days. Think of it this way: eating an outdated batch of overnight oats that haven’t been opened in a few days should taste a little sour.

If it still tastes good, you can probably just eat it. If, after a few days of eating it, the oats no longer taste okay but seem okay, then you may be able to store them and enjoy them at some point in the future.

If they still don’t taste good, they should be thrown away. We don’t recommend storing overnight oats for more than a week before putting them in the garbage or recycling bin!

Are Overnight Oats Healthy?

There are many people that swear by overnight oats as their go-to breakfast for a quick and healthy meal. Overnight oats are loaded with fiber, protein, and nutrients that can keep you full for hours without an added sugar or calorie intake.

Benefits aside, there are also health benefits to eating overnight oats on a daily basis that are ideal for weight loss. Oily foods like protein powders can cause an imbalanced diet, leading to weight gain. Eating overnight oats will help fill you up and keep your body satisfied while dropping pounds.

Everything you Need to Know About Overnight Oats

Why Are Overnight Oats So Filling?

Overnight oats are packed with a lot of fiber, and oatmeal’s soluble fiber will fill you up even more than normal. When you eat fiber, your stomach has to work harder to break down the food and absorb the nutrients because it takes longer to travel through the digestive system. For this reason, fiber is listed as one of the healthiest foods with a staggering amount of health benefits.

Insoluble fibers like oatmeal will keep you fuller for longer and can help lower cholesterol and blood pressure levels that are often linked with heart disease. Fiber is also great for digestion when you are eating cold foods like overnight oats.

The overnight oats won’t sit in your stomach for too long, preventing gas, cramps, and bloating after eating fiber.

What Is The Secret To Overnight Oats?

The secret to overnight oats is just that: making it a routine to make overnight oats before going to bed. Having a batch ready in the pantry from the night before will give you more time to eat breakfast once you’re up in the morning.

If you have no time in the morning, then try adding a bunch of sliced fruit or nuts into some cold water and leaving it for at least 10 minutes before drinking it. It’s that easy!

Why Do People Use Mason Jars For Overnight Oats?

People love using mason jars for overnight oats because they are very convenient. The jars are usually plastic and considered microwave safe, so you can stick the jar in the microwave and heat up your oats without a problem. The lids have a rubber seal that makes the jar airtight, so food doesn’t get stale or go bad quickly.

If you’re trying to cut down on your waste from plastics and other products, then investing in some mason jars for food storage is one of the best things you can do to help preserve resources and save money.

Frequently Asked Questions:

Are Overnight Oats Raw?

We wouldn’t say regular overnight oats are ‘raw,’ but some recipes online for raw overnight oats don’t require any cooking.

Can I Eat 3 Day Old Overnight Oats?

3 day old overnight oats don’t taste that great and could be a little toxic. If you want to use them, make sure they haven’t gone bad. If they’ve stayed in the pantry for more than a few days, try using them in smoothies or adding them to yogurt.

Can You Heat Overnight Oats?

Yes, and yes. Most overnight oats will have instructions on how to do this on the back of the jar. The heating instructions vary depending on the recipe, but most people heat their oats for around 20 seconds in the microwave and add some liquid. If you are worried about your food going bad, then try storing cooked overnight oats in a mason jar and sticking them in the refrigerator or freezer to ensure they last longer.


Overnight oats are the perfect breakfast to eat when you are trying to start a new morning routine. Making and eating overnight oats will keep you full for hours, making it great for those who need quick nutrition that can help weight loss.

We don’t recommend storing overnight oats for more than a week before putting them in the garbage or recycling bin!

My name is Naznin Aktar. I'm a healthy and active person. I believe in eating healthy, staying active, and getting all the rest my body needs. I also like to try new recipes, especially when they are delicious, so those are my recipes... Hope you like it! Thank you for your time!
Naznin Aktar