How Long Does Oatmeal Last? Shelf Life and Storage Tips

How Long Does Oatmeal Last? Shelf Life and Storage Tips

Estimated time to read 7 minutes

Oats are one of the healthiest grains on earth, and regularly consuming oatmeal is a sure-shot way of achieving an all-around improvement in your health.

From various cardiovascular health-promoting antioxidants to an incredible range of vitamins and minerals, oatmeal is a superfood that can help you to lose weight, prevent heart disease and provide other immense health benefits.

A low carbohydrate fiber-rich food makes oatmeal a powerhouse of a meal that can elevate any morning. As one of America's favorite breakfast foods, it is important to know how long this pantry staple lasts. 

These tips are fundamental for knowing how to correctly store oatmeal, especially as dry oats have a tendency to go bad if they are not properly stored. As oatmeal is such a common food choice, many households likely share this problem. 

Oatmeal - Eat Proper Good

Does Oatmeal Go Bad?

Both cooked and uncooked oatmeal can expire. Oats themselves are dry food, and because of this, they naturally have a relatively long shelf life. Despite this, dry oats can still spoil if they are not stored properly. 

Note that incorrect storage of dry oats includes being left in the damaged original packaging (if store-bought packaged oatmeal). 

Additionally, dry oats can also go bad if they are overly exposed to moisture, direct sunlight, heat, and humidity - which is usually the case when oats are purchased from no-waste eco stores.

Cooked oatmeal, when stored efficiently in an sealed food container, can last in a refrigerator for up to a week. If not refrigerated and left at room temperature, bacteria can start to grow in cooked oatmeal, which is a concern for food safety. 

As such, any cooked oatmeal left outside of the fridge for 2 or more hours should be considered as expired, and consequently, put in the trash.

Has My Oatmeal Gone Bad? Ways You Can Tell

There are several key indicators that your Oatmeal has gone bad or spoiled completely. You need to know what to look out for, so take note of the following to gauge whether your oatmeal has expired more easily.

Smell and Taste:

If you are eating oatmeal that has gone bad, you will know! Expired oatmeal has a rancid taste, which indicates decomposition and an excess of bacteria. 

Similarly, both cooked oatmeal and uncooked oats will start to smell bad once they have expired, so look out for any drastic changes in smell or an ongoing off smell.

These signs of expiry are more likely to occur when leftover oatmeal has been left exposed in a room temperature setting, which enables the oats to oxidize.

Presence of Mold:

Mold growing in your oats is one of the clearest ways to tell if oatmeal has reached its expiration date. Oats develop mold due to overexposure to humidity, often caused by improper storage. In turn, this causes oxidation and can lead oats to turn rancid.

You should not eat oatmeal with mold, it is not safe and you need to throw it away.

Color Changes: 

Any discoloration is also a tell-tale sign of spoiled oats. You will want to be wary of developing dark spots that were not previously there. Discoloration is usually caused by exposure to excess moisture, due to poor storage.

Discoloration can quickly lead to mold and texture issues, so as a general rule, dispose of oats as soon as you notice discoloration.


If your oats are clumpy and sticking together, it is best to throw them away! 

How Long Does Oatmeal Last? 

As mentioned previously, oats benefit from being a dry food, enabling them to have a long shelf life. When left undeterred in their original packaging, oats can generally last anywhere between 2 to 10 years, when stored efficiently in a pantry or cupboard, without going bad.

Though nearly all oat brands and oatmeal-based products have 'best by' expirations dates on their packaging, these dates usually signpost when food passes its peak taste time period. Whilst they are a good indicator of product life, they do not fully reflect how long oats can last.

The shelf life of oats and oatmeal products is subject to change depending on how they are stored as well as what type of oats are in question. The product may outlive the best by date, or spoil prematurely. The average shelf life of oatmeal is largely dependent on several factors.

These include the following: 

The Type of Oats

How long your oats last is highly dependent on the type of oats that you are using. For example, cooked oats will not last as long as a portion of uncooked oats due to different moisture levels. 

Cooked oats will last up between 3 to 5 days when stored in the fridge, whereas uncooked oats can last between 1 to 2 years if stored in a cool, dry place.

On average, steel-cut oats have a longer shelf life than other types of oats, such as instant and rolled oats, and can last 2 years when correctly stored.

Flavored oatmeal differs slightly due to its added ingredients, and therefore, lasts an average of 6 to 9 months. 

Storage Area and Method

How you store your oats is equally as important when it comes to prolonging shelf life. For cooked oatmeal, you will need to store it in an airtight container in a fridge. You should not leave prepared oatmeal in room temperature conditions as it will start to grow bacteria and be unsafe to eat.

For uncooked oatmeal, store in a dry, cool place in order to retain quality. Place the oats into an airtight container, such as plastic or glass Tupperware, and store them in a cupboard or pantry.

Oatmeal Storage Tips- Improving Oatmeal Shelf Life

Oatmeal - Eat Proper Good

There are several tips and tricks that you can use to improve and preserve the shelf life of oatmeal. These tips largely have to do with how the oatmeal is being stored. For cooked oatmeal, slightly different techniques may be employed, but preserving the shelf life of dry oatmeal can be boiled down to a few methods.

These methods are as follows:

Storage Containers

You will want to store oatmeal in an air-tight and water-tight container. This will reduce exposure to moisture and excess oxygen, enabling the oatmeal to last longer. 

Glass, ceramic, and plastic materials work best to minimize oxidation, so try to use Tupperware made out of those materials.

Storage Location:

Store oats in dark and dry areas, such as in a cupboard or a cool panty. By doing this, you will prevent your oatmeal from being exposed to heat, light, and moisture. If exposed to these elements, oatmeal can start to grow mold, smell bad, and discolor.


If needed, you can freeze oatmeal or refrigerate prepared oatmeal, but we recommend frequently checking on the quality of the oats to ensure they have not spoiled. 

You should only refrigerate your oatmeal once it has cooled, and aim to eat it within 5 days. After a 5 day period, the oatmeal may not be safe to eat due to bacteria.

In the fridge and freezer, make sure to store the oatmeal in an airtight container.

Risks of Consuming Expired Oatmeal

You will generally know when you are consuming expired oatmeal due to the off smell and taste. As a result, it is unlikely that you will eat much of it. Therefore, there are not too many risks when it comes to consuming expired oatmeal.

You may experience slight nausea and an upset stomach, but this should go away after a few hours. Drinking water will help to flush it out of your system.


In summary, oatmeal should be stored in a cool, dry place in an airtight container. If cooked, make sure that you leave the oatmeal to cool before placing it in the refrigerator.

Dry oatmeal has the ability to last up to 2 years when properly stored, so start using these tips and tricks today! 

But, if you’re looking for ready-cooked oatmeal with a longer shelf life look no further than Proper Good Oatmeal!  Thanks to a dose of science and some awesome packaging technology Proper Good Oatmeal will remain in tip top condition for 12 months, fully cooked and unrefrigerated.  So if you need delicious good-for-you oatmeal made with clean ingredients and ready in just 60 seconds check out the Proper Good oatmeal range here!

Ready made oatmeals - Eat Proper Good

For other foods with a long shelf life, check out the ready-meals at Proper Good. These delicious and nutritious meals can be stored in a pantry or cupboard for whenever you need an instant boost and a delicious filling meal!

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