How Long Does Oatmeal Last? A Satisfactory Answer

Oatmeal is a nutritious and versatile whole grain that is amazing for many cereal recipes. I love using them for classic oatmeal and milk or oatmeal pancakes with peanuts. They are also known for being a long shelf-life food. But that doesn’t mean they will always be safe to eat.

So how long does oatmeal last? Let’s find out in my post now!

Can Oatmeal Go Bad?

Can Oatmeal Go Bad

Oatmeal is a tasty dish but do oats go bad? or do oats expire? Let’s find out now!

Can Rolled Oats Go Bad?

Old fashioned oats, or also known as rolled oats, are the lightly processed whole grains type. They are made from oat groats, which are then dehusked and rolled into flakes. These flakey oats, when properly stored, can last up to one to two years. If the oats contain no stabilized oil, they can also go rancid easily.

Do Quick Oats Go Bad?

There are many commercial oats like Quaker in the market, such as instant oats, steel-cut, and quick oats. These commercial ones can last longer in the normal temperature because they have been thoroughly processed.

For quick oats, they have been dehusked, steamed, and toasted slightly for stabilizing the oats’ groats. After this process, the oil inside the oat grains will be stabilized, allowing them to last longer. However, they can go rancid if their package is not safe enough to store.

If the package of dry oatmeal is made of paper, there is a high risk for moisture and airborne yeast to penetrate the bag and spoil the oats. Once they penetrate, it is also difficult to spot any signs of yeast, while mold can be shown through dark spots. 

The only way for you to know if the oats are affected or not is by tasting them. These yeasts will result in a sour taste which is too late to save any oats left in your package.

Therefore, to prevent oats from being spoiled, I tend to pour all those grains into an airtight container so that they are safe from any external penetration.

Now that you know oats can go bad, what if you cook them? Once they are cooked, should they kill all of the bacteria?

Does Cooked Oatmeal Go Bad, or Do Overnight Oats Go Bad?

It is common to think that cooked food won’t be spoiled because you eliminate all the bacteria. That fact is partly true. When the prepared oatmeal is cooked, they are super safe to eat as the bacteria cannot grow more than 140 degrees Fahrenheit.

However, it is another story if you leave the cooked oatmeal for a long time at room temperature. In case you leave them for too long at room temperature, the oatmeal will go bad quickly because of the bacteria’s growth.

How Long Does Oatmeal Last?

Normally, we tend to use up the whole oat package in just a few months or less, depending on how you use them in your daily meals. So, how long are oats good for?

You don’t need to worry about whether they expired or not, as these commercial oats can easily last up to 2 years if they are stored properly.

However, there can be some exceptions and factors that affect the life shelf of oats. The most common element is additive ingredients. This happens to the packet of flavored oatmeal. 

They tend to have a shorter shelf life from 6 to 9 months. This is because this oatmeal also adds some fruits and cream to their package, which destabilizes the compact structure of the oat.

Some oatmeal packages that are labeled as unsteamed or unstabilized also have a shorter shelf life as well because of the oil inside the oats. Although rolled oats can taste more natural, they don’t last as long as the processed packages. 

 Maybe you have lost count of how long your oats have been around in your kitchen; don’t worry, you might still be able to use them.

The famous commercial oat brand Quaker Oatmeal,  also confirms that the packages are still safe food even when the expiration date has passed. However, they may experience some changes in the taste if you don’t store it properly.

Now let’s find out how each type of oatmeal can last.

How Long Are Rolled Oats Good For

Rolled oats or traditional oats have a long shelf life when they are properly stored. These oat grains can still be good up to 18 months while at room temperature.

How Long Are Steel Cut Oats Good For

Steel-cut oats, instant oatmeal, or Irish oatmeal are oats that have been sliced into small pieces instead of flattened out like rolled oats. So, how long do steel cut oats last? Or how long is instant oatmeal good for?

They are the healthiest oat grains among the oats because of the minimal process. When you leave them in the right condition, they will last up to 2 years in your kitchen!

How Long Does Cooked Oatmeal Last

Although oats have a longer shelf life than most food, their cooked version doesn’t last so long at room temperature. So, how long is cooked oatmeal good for?

According to the FDA, you should discard all the food that leaves at room temperature for more than 2 hours to ensure food safety. The reason is the bacteria start to grow rapidly once they meet the room temperature or the danger zone (40 degrees Fahrenheit to 140 degrees Fahrenheit). In just 20 minutes, they can easily double their population!

However, you can prolong the life of oatmeal if you place them in the fridge.

How Long Does Oatmeal Last In The Fridge

Oatmeal can be so tasty to have that we want to keep them for longer use. Normally I tend to make a whole batch for my family for breakfast or lunch. Sometimes we have leftover oatmeal that is enough for another meal. In those situations, I always leave them in the fridge once they are cooled down.

For a short duration time at room temperature, cooked oatmeal has quite a long lifespan when hanging out in the fridge. This is because of the low temperature keeping the bacteria growth slow down tremendously. Thus, we can have a longer use for our favorite oatmeal.

When being in the fridge, your oatmeal can last from 5- 7 days when they are stored properly. Many people tend to miss the preparation before storing food leading to spoiled and bad oats after just 1-2 days.

How To Tell If Oatmeal Is Bad? 

So you have been leaving your bowl of oatmeal in the fridge for a long time, how can you know if oatmeal is bad? As the label cannot tell when to throw rancid oats away. Here are some distinguishing signs of spoilage.

The easiest way to find out whether your oatmeal has spoiled is by looking at the discoloration. Natural oatmeal will have cream and brown color. If there are any suspicious white or dark spots in your oatmeal, it could have been contaminated by mold and yeast growth.

When you find those spots, it is recommended to discard all of that spoiled oatmeal, or else you might have food poisoning. Moreover, the mold and yeast will spread to other food inside the fridge as well. That will be the last thing you want: contaminated bad food.

Another sign of spoilage is an off-putting smell. It can smell sour and bitter instead of the nutty smell of usual oatmeal.  That’s when the fats and oil start to go rancid.

Lastly, the taste of oatmeal will bear an awful taste instead of that sweet, creamy, and nutty flavor of the fresh oatmeal. When they are in the spoilage process, the taste will become too sour and stale to eat.

No matter what the signs are, you should follow the preparation rule to store them properly. Only then can your delicious dish be safe for a long time.

How To Store Oatmeal

Storing oatmeal is an important step to keep the food fresh for a longer time. Usually, you can find two common and effective storage of oatmeal are refrigerating or freezing oatmeal.

How To Store Rolled Oats

For the oats package, you can keep them at the normal temperature for a longer time if you store them properly. So, it is necessary to know how to prepare these foods before storing them.

Oat packages need a dry and cool place without any direct exposure to light. Therefore, you need to pour them into an airtight container like a glass jar to store them.

How To Store Cooked Oatmeal

For cooked oatmeal, you should also put them in an air-tight container, plastic wrap, or resealable plastic freezer bag before storing them. This will protect them from any exposure to moisture, potential mold, and yeast growth or affect the taste and flavor of oatmeal.

Similar to storing biscuits, the best way to store oatmeal is to place it in the refrigerator so that you can still maintain the taste and texture of the dish.


Can Rolled Oats Go Bad

Can You Eat Expired Oatmeal?

As I have mentioned above, the expiration date on the oatmeal packs is not the end of everything. You can still eat the oatmeal after the expiration date but with a slight change of taste.

Can You Eat Dry Oats?

Oats are commonly cooked with milk or water, so can you eat old-fashioned oats raw? The answer is yes! You can eat that raw oatmeal because they have already been pre-steamed.


Oatmeal is one of the quickest and easiest dishes to make for your breakfast or lunch. Sometimes we tend to make more than we can eat, resulting in leftover oatmeal. Knowing the answer to the question, “how long does oatmeal last?”

We can use that information to store them properly and plan our daily meals better.

Kevin Richard

Hi all! I’m Kevin. I spend plenty of time in the kitchen every day because I love cooking healthy and delicious foods for my family and friends. Cooking gives me a chance to be creative and fun. It’s also one of the most meaningful ways to express my love and take care of my little family.

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