Does oat milk go bad? (Explained)

There’s a surge in oat milk’s popularity, likely due to its many benefits over traditional dairy milk. Oat milk is lower in calories, cholesterol, and sugar than cow’s milk, and it also contains more fiber, potassium, and vitamins A, D, and E.

But does oat milk go bad? And if so, how long does it last?

Refrigerated oat milk does have a shorter shelf life spanning a few weeks after production, and will last about seven days after opening if stored properly. The key to storing oat milk is to keep it cold, just like cow’s milk; store oat milk in the fridge, in a container with a tight-fitting lid.

On the other hand, shelf-table oat milk can last several months past its date. However, this only applies if the bottle or carton remains unopened. Once it’s opened, refrigerate to preserve its quality.

To extend the shelf life of oat milk, you can freeze it. Frozen oat milk will last for about three months. Thaw it in the fridge overnight when you’re ready to use it. Once thawed, you should use oat milk within seven days.

How can you tell if oat milk is bad?

There are a few telltale signs to watch out for, and the most obvious are:

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  • Discoloration or separation
  • Chunks or lumps
  • A sour smell
  • Presence of mold

If you find any of these signs, it’s best to discard the milk and not satisfy your milk craving. Don’t attempt to fix or make it last longer, as it’s no longer safe to consume.

What happens if you eat spoiled oat milk?

Eating spoiled oat milk can cause food poisoning. The symptoms, which usually begin within hours of eating, can include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach cramps
  • Fever
  • Body aches

If you experience any of these symptoms after eating oat milk, see a doctor as soon as possible. Food poisoning can be serious, and in some cases, it can even be life-threatening.

Can you drink expired oat milk?

No, you should not drink expired oat milk. Like any other dairy product, oat milk can go bad, and paying attention to the expiration date is essential. Once oat milk expires, it’s no longer safe to drink.

You will be putting yourself at risk of food poisoning if you drink expired oat milk. So, don’t take the chance even if it doesn’t look or smell bad.

Does oat milk need to be refrigerated?

Yes, oat milk needs to be refrigerated, especially if you buy refrigerated oat milk. It will spoil if it’s not stored properly—store oat milk in the fridge, in a container with a tight-fitting lid.

However, shelf-table oat milk that hasn’t been opened can be stored at room temperature. Once opened, though, it needs to be refrigerated.

How long can oat milk sit out without refrigeration?

Oat milk can sit out at room temperature for up to 2 hours without refrigeration. After 2 hours, though, it needs to be refrigerated. The 2-hour duration is a guideline by the US Department of Agriculture for perishable foods.

If it’s a hot day, or if you think the oat milk has been sitting out for longer than 2 hours, it’s best to throw it out.

Can oat milk be left out overnight?

No, you should not leave oat milk out overnight. Once oat milk is opened, it needs to be refrigerated. If you leave it out overnight, it will spoil, and drinking is no longer safe.

So, if you accidentally leave your oat milk out overnight, don’t try to salvage it; throw it out and buy a new one.

Tips to keep oat milk fresh and last long

Here are some tips to keep oat milk fresh and make it last longer:

  • Store oat milk in a container with a tight-fitting lid in the fridge.
  • If you buy shelf-stable oat milk, don’t open it until you’re ready to use it. Once opened, transfer it to the fridge.
  • Freeze oat milk to extend its shelf life. Thaw it in the fridge overnight when you’re ready to use it.
  • Pay attention to the expiration date, and don’t drink oat milk after it expires.
  • Don’t leave oat milk at room temperature for more than 2 hours.
  • Shake the bottle before using, as oat milk can separate.

Closing thoughts

Oat milk can go bad, just like any other dairy product. To extend its shelf life, store it properly and consume oat milk within seven days after opening.

Discard the oat milk if you see any spoilage, such as discoloration, chunks or lumps, a sour smell, or mold. And don’t try to drink expired oat milk, as it can cause food poisoning.

These tips will help you enjoy oat milk for as long as possible. But remember that even when stored properly, oat milk lasts only for a certain period. So, be sure to check the expiration date before buying.

Jude Uchella is a research writer and a strong advocate for health and fitness. He takes pleasure in helping people live their best life. When he's not writing, he's probably researching the next topic to write about. :)