How Long Does Oat Milk Last?

You’ve bought a carton of oatmilk, drank a glass, and put the rest in the refrigerator. Now you’re wondering: how long does oat milk last in the fridge?

Or maybe you just got home with a carton or two, and you’re not sure where to put it. Should you refrigerate oat milk, or can it sit on the counter?

If either sounds familiar, or you would like to learn about storage, shelf life, and going bad or oat milk (or oatmilk), you’re in the right place.

Keep reading!

Oat milk in hand

How Long Does Oat Milk Last?

An open carton of oat milk keeps for 4 to 7 days if you keep it in the fridge.

Some producers, like Tōats ([TOATS]), go with the lower end of the spectrum, while others, like Oatly ([OATLY]), have more relaxed guidelines and give you a week to enjoy their product.


If you finish the carton within about 4 to 5 days, you should be in the clear no matter the brand.

When it comes to storage time of an unopened oatmilk, things are more complicated.

There are two types of oat milk on the market – shelf-stable and one that’s sold refrigerated.

The shelf-stable one comes with a best-by date, which in most cases is 6+ months from the production date. And the milk alternative often keeps quality for at least a couple of months past that date.

Oat milk date on label
Oat milk date on label

How long is oat milk good for after the best by date? In most cases, at least a month or two, possibly more. Always check the product for spoilage when it’s past its date.

When it comes to oat milk that’s sold chilled, it often comes with a sell-by date ([TOATS]), and the product retains quality only for a week or so of that date.


If your oat milk didn’t sit in the fridge in the supermarket, it’s the shelf-stable type. Same thing if the label doesn’t clearly say it needs to be refrigerated at all times.

Oat milk (shelf-stable)Best-by + 1 – 3 months
Oat milk (chilled carton)Sell-by + 5 – 7 days
Oat milk (opened)4 – 7 days

Please note the periods above are estimates only.

Glass of oat milk
Glass of oat milk

Does Oat Milk Need To Be Refrigerated?

Once you open the carton, you need to refrigerate oat milk no matter the type.

When it comes to an unopened carton, it all depends on the type.

Shelf-stable oat milk can sit in the pantry, on the countertop, or anywhere else away from sources of heat.

Chilled cartons require refrigeration, so make sure to put them in the fridge when you get back home.

Coffe with oat milk
Coffe with oat milk

Wondering why some of the cartons need to sit in the refrigerator while others do not?

In most cases, the difference isn’t in the ingredients but in the packaging.

Oatly ([OATLY]) brand explains it well on their website:

The shelf-stable cartons are packaged in an aseptic format that produces a totally sterile environment, resulting in a product with a longer shelf life and no need for refrigeration (until it’s been opened for the first time, that is).


The cartons that require cold temperatures simple aren’t aseptically packaged.


One type isn’t better than the other, but shelf-stable cartons are much more convenient if you want to stock up.

Alpro oat milk container
Alpro oat milk container

How To Store Oat Milk

Besides keeping the carton in the right place, which I explained above, there are a few other basic practices to remember about. Those are:

  • Always keep the carton sealed tight when not in use.
  • Don’t drink straight from the carton (unless you know you’re going to finish it).
  • Pour as much oat milk as you need into a glass a put the carton back in the fridge.
  • If your carton isn’t easily resealable, transfer the milk into a plastic container or a glass jar.

If you’re a regular consumer of coconut milk, almond milk, or rice milk, I’m pretty sure you follow those already.

Oat milk in a glass: closeup
Oat milk in a glass: closeup

How To Tell If Oat Milk Is Bad?

When you check if your oatmilk is okay to use, do the following:

  • Check consistency. If the liquid is chunky or pretty thick, it’s gone. That’s why you first pour it into a glass before drinking.
  • Consider the color. If the milk alternative has turned yellow instead of creamy, discard it.
  • Perform a sniff test. Your good old nose is an excellent detector of spoiled foods – use it. If the liquid smells sour or off in any other way, it’s done for. Check both the liquid in the carton and the glass.
  • Taste it. If everything else seems to be okay, chances are your oatmilk is safe to drink. But before you pour that glass into your pancake batter, it’s always better to give it a try. If there’s anything off with the taste, throw it out.

The longer an open carton sits in the fridge, the worse the quality. The difference isn’t that big, and most people (including yours truly) hardly notice it.

Last but not least, let’s talk about storage time.

If your oat milk passes all the tests above, but it sits in the fridge for more than 10 days, discard it.

It’s not necessarily expired, but it’s better to be safe than sorry.