» Does Soy Milk Go Bad?How Long Does It Last?

Does Soy Milk Go Bad?How Long Does It Last?

Soy milk offers incredible benefits to our bodies. That said, it’s not surprising that you probably have a carton (or two) in your pantry or refrigerator. But how long have you had that packet of milk sitting in storage? Is it still good? Let’s learn a couple essential things about soy milk’s lifespan and we will find out.

Does Soy Milk Go Bad?

Does Soy Milk Go Bad

Yes, soy milk, like other milk types, does go bad. Whether it is the refrigerated or shelf-stable type, as soon as the carton is opened, the milk starts to degrade and will not last very long.

Unopened, refrigerated soy milk should be stored in the fridge at all times. It has a pretty short lifespan; so much so that it will go sour if left at room temperature overnight.

Unopened, shelf-stable soy milk, on the other hand, can be easily stored at room temperature and not get spoiled. The package will come with a best-by date to show how long the product will stay good for.

If stored properly, the milk will retain its quality for several months beyond the printed date. But as soon as the seal is broken, the milk must be stored in the refrigerator.

How Long Does Soy Milk Last?

Shelf-stable soy milk has a longer shelf life than soy milk from the refrigerated section. When stored correctly, it can last anywhere between two to five months past the best-by date. The story is different with refrigerated soy milk. This will keep good only for about seven days beyond the printed date.

After a carton or bottle has been opened, soy milk must be finished within six and twelve days, whether it is the refrigerated or shelf-stable type.

It is important that you don’t leave your opened soy milk at room temperature. According to the University of Nebraska – Lincoln, perishable foods should not be left sitting out for more than two hours. Bacteria multiply quickly at room temperature and foods that are left on the counter for longer than this period should be thrown out.

Soy milk falls under the category of perishables, and the longer it stays out, the more it is likely to spoil. Well, an opened packet of soy milk may still look fine after the two hours but if it has been left out overnight, it should be discarded.

Here is a quick summary of soy milk’s shelf life.

Type of Soy Milk Lifespan
Refrigerator Pantry
Unopened, shelf-stable soy milk N/A Best-by date + 2 to 5 months
Unopened, refrigerated soy milk Best-by date + 7 days Not recommended
Opened, shelf-stable soy milk 6 to 12 days Not recommended
Opened, refrigerated soy milk 6 to 12 days Not recommended

4 Tips to Tell if Soy Milk Has Gone Bad

Tell if Soy Milk Has Gone Bad

The symptoms of soy milk that has gone bad will be very similar to that of spoiled cow’s milk. Some indicators include:

1.    Bloated Carton

If your milk packet is swollen, that is a clear indication that there are some bacteria in the packet and the product has gone bad.

Most of the time, it happens when the milk is not stored properly, for instance, if the product is left at room temperature for too long, causing bacteria to grow rapidly. These microbes feed on the milk and release gas, and since the carton is sealed, this gas cannot escape. It collects inside, causing the packet to swell.

Bacteria usually sneak into the food packaging during the manufacturing process. If the packaging equipment is not clean, it will transfer bacteria into the packet, contaminating the milk. Always avoid purchasing bloated pouches.

2.    Prolonged Storage

Soy milk manufacturers will print a best-by date on the package to show how long the product will stay fresh for. Depending on whether the product is refrigerated or shelf-stable, you can consume it a few days or even months after this date.

However, if the product has stayed in storage for way too long, chances are it has gone bad and should not be ingested.

3.    Change in Color or Texture

Good soy milk usually has an opaque white or off-white color and a decently thick texture. When it starts to go bad, the product may turn a rotten color or yield a runny or curdled texture. If you notice a change in color or consistency, that could be a sign of spoilage.

4.    Sour Smell

Another easy way to tell if soy milk is safe to consume is to smell it. All milk types will have a rancid odor if they are contaminated with bacteria or mold. If the smell of your soy milk is off, it’s time to let that carton go.

This video shows you more ways through which you can tell if milk has gone bad. You can use these same tricks to find out if your soy milk is still good.

3 Tips to Store Soy milk

As with all milk types, proper storage is key to helping your soy milk last longer. If the product is not stored correctly, it will go bad quickly and will be unsafe to drink. Follow these tips to ensure your soy milk retains its quality longer:

1.    Store Soy Milk in a Cool Place

Shelf-stable soy milk should be kept in a cool, dry place, away from direct sunlight and heat sources to help slow down spoilage. The pantry would be a great spot, but soy milk can stay fresh in any kitchen cabinet provided the cabinet meets the required storage requirements.

As soon as the milk is opened, it should be refrigerated. The refrigerated variety should remain in the fridge all the time.

2.    Keep the Packet or Bottle Tightly Sealed

It doesn’t matter whether your soy milk is shelf-stable or refrigerated. After opening a packet, the leftover should be placed in the refrigerator, properly sealed. This not only prevents any bacteria in the fridge from sneaking into the milk; it also locks out scents from adjacent food items.

The good news is that most cartons and bottles are resealable, so you will likely not have problems storing what is left. However, if the original container cannot be resealed, transfer the milk into an airtight bottle and seal it.

3.    Avoid Drinking the Milk Straight From the Carton

It can be tempting to just grab a bottle of soy milk, take a couple sips, and put it back in the refrigerator. While this may seem super convenient, it is also one of the easiest ways to cause your milk to go bad before its due date.

Why? Because any microbes in your mouth will be transferred to the milk and contaminate it, which will accelerate the spoilage process. Pouring milk in a glass will prevent that; plus it will help you see when something is off.

The Risk of Consuming Expired Soy Milk

The dangers of consuming soy milk that has gone bad are the same as those of consuming any other spoiled milk type. For the most part, your body will exhibit symptoms similar to those of food poisoning such as vomiting, upset stomach, diarrhea, nausea, or even headaches.

Also, drinking spoiled soy milk will literally leave a bad, rancid taste in your mouth. If you suspect your milk has gone bad, it’s best to discard it. Though it may seem like you are wasting food, it’s not worth the risk to eat certain food items after they have been in storage for extended periods.

Apart from putting yourself at risk of food poisoning, expired foods will also tend to be lower in minerals and nutrients so they will likely not benefit your body at all.

The date printed on the package will help you decide whether to eat or trash your soy milk. To avoid having to deal with spoiled soy milk, consume the product before the marked date.

Can You Freeze Soy Milk?

Yes, you can. Frozen soy milk can stay good for up to a year! Keep in mind, however, that the milk separates heavily after thawing, and there is a significant change in texture. Of course, stirring can help even out the milk, but the final product will still not be as smooth and silky as a fresh bottle.

But if you are like most people, these changes will probably not be an issue for you. If that’s the case, you can still go ahead and store your soy milk in the freezer.

Make sure to put it in an airtight container, though. It could also help to portion the milk so you can thaw only the amount you intend to consume. When you are ready to use the milk, let it defrost overnight in the refrigerator.


So, does soy milk go bad? Yes, it does, and when that happens, it becomes a risk to our bodies than it is a nutrients supplier. Check the date on the package to determine the quality of your milk, store the product properly,  and when in doubt, toss it out.


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