How Long Does Soy Milk Last? Do You Refrigerate It?

Here’s all you need to know about storage, shelf life, and spoilage of soy milk. In this article, you will learn if and when it needs refrigeration, and how to tell if yours is bad.

Your half-open carton of soy milk has been in the fridge for a couple of days already, and you’re wondering how long soy milk lasts.

Or maybe you want to check if it’s still okay to use, but you realize you’re not sure what to look for.

Sounds like you? If so, this is the article for you.

For starters, let’s talk about why some soy milk cartons and bottles require refrigeration and others don’t. Knowing the difference between the two will make everything else a whole lot simpler.

Soy milk in hand

Does Soy Milk Need to Be Refrigerated?

Shelf-stable soy milk can sit on the counter until you open it up. After opening, you should store it in the fridge. Refrigerated soy milk, as the name suggests, requires refrigeration at all times.

To make it even simpler, you should store your soy milk the same way it was in the grocery store (meaning in the fridge if it was in the refrigerated section) and keep it in the fridge after opening the bottle or carton for the first time.

You’ve probably noticed that you can find cow’s milk both in the fridges and in the shelf-stable cartons section. Soy milk works the same way, and other dairy-free milk alternatives like oat milk, coconut milk, and rice milk do too.

That said, you might be interested in learning a bit more about the differences between refrigerated and shelf-stable soy milk. For instance, to know why the latter doesn’t require refrigeration and if that has anything to do with preservatives.

Let’s go over that.

Refrigerated vs. Shelf-Stable Soy Milk

The difference between refrigerated and shelf-stable soy milk is in packaging and how the liquid is processed, not the ingredients themselves.

Here’s how Silk describes it:

“Shelf-stable” refers to the special packaging some of our products come in. Shelf-stable packaging is sterile and airtight, so it can be safely stored at room temperature.

That means, in most cases, the shelf-stable soy milk is just as “clean” in terms of ingredients as the refrigerated variety (but check the ingredients list to be sure).

Some brands make differentiating between varieties easier by making shelf-stable products in cartons and refrigerated ones in bottles. That’s the case for Califia Farms, a plant-based milk producer I mentioned in the article on oat milk shelf life and storage.

Please note, however, that not every brand makes both varieties. Smaller ones usually only offer the shelf-stable one, as it can be easily sold both online and to retailers.

The bottom line is both refrigerated and shelf-stable soy milk are similar in ingredients, and the two differences that matter are the way you store them and how long each one lasts. More on the latter in a moment.

Note

Most plant-based milk alternatives are available in both shelf-stable and refrigerated varieties. That’s why you can find a similar discussion in other articles that cover these, for example, the Does almond milk go bad? article.

Soy milk closeup
Soy milk closeup

How Long Can Soy Milk Sit Out?

The official USDA guideline for perishable products (which open soy milk is) is that you should discard it if it was left out at room temperature for more than two hours.

Obviously, it is up to you to which degree you follow this recommendation. In most cases, your soy milk will be fine after those two hours, but you never know.

One thing’s for sure: if your half-open soy milk has sat on the counter for the whole day, or you left it out overnight, it’s time to let it go. Always err on the side of caution in this matter.

Other Storage Practices

Now that you know where each type of soy milk belongs, let’s go over a couple of basic storage practices. You’re probably familiar with most of them, so I’ll keep things brief.

Here’s the list:

  • Keep your soy milk carton or bottle sealed.
  • If yours comes in a carton that you cannot reseal, transfer the rest into a resealable container or a mason jar.
  • Shake the carton or bottle before pouring.
  • Always pour this plant-based milk instead of drinking straight from the package. That keeps the tip clean, plus you can notice that things are off when pouring.

That’s it. If you follow all of the above, chances are your soy milk will last as long as possible. Let’s talk about how long that period is.

A carton of Alpro soy milk

How Long Does Soy Milk Last?

Shelf-stable soy milk lasts for a few months past the printed date. Refrigerated soy milk, on the other hand, keeps only for about a week past its date.

Once you open a bottle or carton, you should finish it within 5 to 10 days, no matter the type.

Knowing the basics, let’s talk about how you should go about expired soy milk.

 PantryFridge
Shelf stable (Unopened)“Best by” + 3 – 6 months 
Shelf stable (Opened) 5 – 10 days
Refrigerated (Unopened) “Use by” + up to 7 days
Refrigerated (Opened) 5 – 10 days

Expired Soy Milk

As I talked about in length already, there’s shelf-stable and refrigerated soy milk available on the market. And besides storage, the essential difference between the two is their shelf life.

Shelf-stable soy milk comes with a best-by date that’s at least 12+ months from the production date. And, thanks to the aseptic packaging, it keeps for at least a couple of months past the printed date, assuming that it’s unopened.

On the other hand, refrigerated soy milk has a use-by date that’s up to a couple of weeks from the date it was bottled and can last for a couple of days to maybe a week past that date.

So if you’re wondering if your “expired” soy milk might be okay to use or not, start with the type.

If it’s the more popular shelf-stable variety, it’s going to be okay for months after its date, so as long as you’re comfortable using it, open the carton, check if it’s okay (more on that later), and use it if everything is fine.

For the refrigerated variety, it’s probably best to toss it if it’s more than, say, a week past its date. It’s not necessarily spoiled, but it’s not safe to drink anymore.

Tip

If you want to make soy milk your coffee creamer of choice, try the Barista blend of your favorite brand if such an option is available. Barista versions of plant-based milk typically steam and froth much better than regular ones, and the taste and feel are more similar to that of cow’s milk.

Soy milk in a glass
Soy milk in a glass

After Opening

Soy milk lasts 5 to 10 days after opening the bottle or carton for the first time.

This recommendation varies between brands. The minimum is about 5 days recommended by Alpro, while many other brands go with a 7 to 10-day recommendation (e.g., Silk).

The recommended storage period is more about quality than safety, though. Pretty much all soy milks out there should keep for more than 5 days of opening, but the quality on day 6 or 7 might be quite bad. But, again, it all depends on the brand, so feel free to test how long yours keeps for.

If you already know you’re going to store it for a long time when you open the milk, consider freezing it. While soy milk doesn’t freeze that great, there are a couple of ways you can successfully use it after freezing.

Read more: Can you freeze soy milk?

Tip

After you open the carton or bottle, grab a marker and write the date on the label. I keep one near the fridge exactly for that purpose. This way, you can easily keep track of how long it’s open.

Finally, if you’re considering using soy milk that’s been open for longer than recommended, be smart about it. If it’s a day or two, it’s worth checking if it’s still usable. But if it’s two weeks since you opened it, toss it.

How to Tell if Soy Milk Is Bad?

To check if your soy milk is okay to use, do the following:

  1. Check the dates. If it’s open for too long or way past the printed date (depending on the variety), you should discard it no matter if it seems okay or not. Look for details in the section on shelf life and storage time.
  2. Smell it. If you notice any hints of mold, or it smells sour or mold, throw it out.
  3. Shake the bottle or carton and pour some.
  4. Check the color and assess the consistency. If your soy milk is lumpy, slimy, or heavily separated, it’s done for. Same thing if there are some discolorations, any signs of mold, or anything else that doesn’t look right.
  5. Taste it. If everything seems to be okay, checking the taste is the last piece of the puzzle. Remember that soy milk from different brands tastes differently, and the consistency can differ too. Some are thin, while others are smooth and creamy – it all depends on the brand. If the non-dairy milk alternative tastes sour or plain bad, pour it down the drain.

If your soy milk doesn’t show any signs of spoilage that I listed above, and you don’t notice anything else that’s off or iffy (better safe than sorry), chances are it’s okay to use.