Drinking spoiled milk can easily ruin your day.
It’s an unpleasant experience that leaves a bad taste in your mouth. You might even suffer from food poisoning if you’re unlucky.
You can tell if soy milk has gone bad if it has a yellowish color, lumpy texture, unpleasant smell, or a sour taste. Checking the condition of the milk package and the expiry date can also help you figure out if the milk is spoiled.
In this article, you’ll learn more about the signs you should watch out for so you don’t consume spoiled soy milk. We are also going to share some helpful tips on how to keep your milk fresher for longer.
Signs That Your Soy Milk Has Gone Bad
1. The Expiration Date
Expiration dates show when a product is no longer safe for consumption. Expired soy milk can put your health at risk because of bacterial contamination.
You could experience food poisoning symptoms such as:
- Abdominal pain
- Headaches
- Stomach cramps
- Diarrhea
- Nausea and vomiting
Some brands might add other phrases and labels to describe quality dates.
To avoid confusion, the USDA shed some light on this by explaining the meaning of some commonly used phrases:
Label | What it Means |
|---|---|
Best By | Describes when the product will be of the best quality or flavor. You can still consume food past this date if it doesn’t show any signs of spoilage. |
Use-By | Shows the last date when the product will be of the best quality. It’s only regarded as a safety date when used on infant formula. |
Sell-By | Tells the seller how long the product should be in stock. |
Freeze-By | Shows when you should freeze the product to maintain its quality. |
We also advise you to check if the packaging has specific manufacturer recommendations.
2. The Packaging
Swollen or bloated milk packages indicate that the milk is spoiled. The swelling is most likely caused by gases released by spoilage bacteria.
Don’t consume soy milk if there’s a change in the shape of the package or container.
3. Its Color And Consistency
Pour some of the milk into a clear glass to see if there’s any change in its appearance.
It will have an off-white color if it's good and a yellowish color if it’s spoiled.
Spoiled soy milk will also have a lumpy/curdled texture.
Related: Why Does Soy Milk Curdle in Coffee?
4. Smell The Milk
Spoiled milk produces an unpleasant smell because of bacteria growth.
A foul aroma indicates that your soy milk has gone bad. You should discard it once you open the container and notice there’s something off with its smell.
5. Taste The Milk
Sometimes the milk might look and smell okay even though it's spoiled.
Spoilage bacteria will affect soy milk’s taste. So you should test it first before drinking or using it in your recipes to avoid wasting coffee, cereal, and other foods.
Spoiled soy milk will leave a bad/sour taste in your mouth.
6. Heat It Up
You can heat the milk to check if it’s still good.
There’ll be no change in its consistency if it’s fresh. However, it will have a curdled or lumpy texture if spoiled.
How To Keep Soy Milk From Going Bad
Handling
How you handle soy milk can either spoil it before its expiration date or keep it fresh for as long as possible.
Never drink straight from the carton because you might transfer bacteria to the milk.
Use a cup or glass whenever you want to enjoy some soy milk.
You should also shouldn't put unused soy milk back in the carton or container.
The unused milk might spoil the rest of the soy milk because it’s already exposed to room temperature.
Lastly, ensure the cups and containers you use are clean to avoid contamination.
Refrigeration
Cold temperatures slow down the activity of naturally occurring bacteria keeping food fresher for longer.
A study to prolong soy milk’s freshness found that sterilized soy milk lasted twice as long when refrigerated. This finding applies to different types of soy milk:
- Homemade soy milk quickly expires when left out in the open. But it can last for 3 to 5 days when refrigerated.
- Unopened refrigerated soy milk can spoil within a few hours if stored at room temperature. However, it can last up to a week when refrigerated.
- Opened refrigerated soy milk spoils faster when left out in the open but lasts a few days when refrigerated.
- Opened shelf-stable soy milk should be refrigerated and consumed within 6 to 12 days. Otherwise, you’ll have to toss it away if it sits out for more than 2 hours.
- Opened soy milk powder can last for about 3 months if refrigerated and a few weeks or less when left out in the open.
Always keep the refrigerator temperature at 40 °F or below to keep your milk from spoiling.
You should also use air-tight containers to lock out other scents and keep out bacteria.
Freezing
Freezing keeps bacteria from growing by turning the water in the food into ice crystals.
You can freeze opened soy milk to extend its shelf life. However, keep the following things in mind when you freeze the milk.
Temperature
According to Energy.gov, the temperature in the freezer should always be 0 °F or below for long-term storage. You might need to keep an appliance thermometer in the freezer to monitor the temperature, especially in case of emergencies.
The USDA recommends taking the following measures during power outages or mechanical problems:
- Avoid opening the freezer door if the power will be on soon.
- In case of a mechanical failure, don’t open the freezer door if the repairman is on the way.
- Separate foods like meat and poultry from the milk so that their juices don’t drip on it if they begin to thaw.
- Group milk containers together with dry (non-dripping) foods so that they can retain the cold.
- Put some ice bags, block ice, or dry ice in the freezer and monitor the temperature.
- You can also transfer your food to a friend’s freezer until you resolve the issue.
You’ll need to check the safety of the food once your freezer is working again. The first thing you should do is check the food temperature.
Feel free to use or refreeze the milk if it still has ice crystals, is partly frozen, or is colder than 40 °F.
The USDA recommends discarding contaminated food. You should also dispose of any food exposed to temperatures warmer than 40 °F for more than 2 hours.
Packaging
When freezing, always use freezer-safe plastic containers or freezer bags.
You’ll need to leave some room because soy milk expands when it’s frozen. That’s why glass bottles and cartons aren’t safe because they get damaged when they expand.
Ensure you tightly seal the containers and freezer bags to keep out air. Otherwise, soy milk might react to oxygen and evaporate, leading to freezer burn.
The milk will still be safe for consumption, but the quality won’t be the same, and it'll lose its flavor in the process.
According to the USDA, you can freeze soy milk for about three months. However, the freezing duration might vary depending on the recommendations on the product label.
If you plan on using the soy milk occasionally, you can freeze it in ice cube trays. That way, you can take a few ice cubes whenever you want to use some soy milk in your recipes.
Lastly, we recommend labeling expiration dates on the containers to avoid confusion in case you’d frozen or plan to freeze another batch of soy milk.
Thawing
You can thaw soy milk in water or the refrigerator.
Thawing in the refrigerator takes time, so it’s best to plan ahead if it’s your preferred method. You can refrigerate the milk overnight to use it the next day.
If you’re in a hurry, you can place the soy milk container in warm or cold water. Defrosting it in cold water allows you to use some milk later, as long as it’s within 24 hours. Make sure you frequently check the water and replace it every 30 minutes to ensure it stays cold.
If you defrost it in warm water, you’ll have to use all the soy milk immediately. Warm water encourages bacteria growth, so the milk could spoil quickly.
Thawing in the microwave isn’t recommended because the milk could easily overheat. In the process, you might kill beneficial enzymes and encourage bacteria growth.
The USDA doesn’t recommend thawing food in hot water or on the counter.
You should also avoid leaving frozen food at room temperature for more than two hours because it could lead to rapid bacteria growth.
They also advise against thawing food outdoors. And recommend using leak-proof plastic bags to keep bacteria from contaminating the food.
Keep in mind that you can’t refreeze milk that’s been frozen and thawed.
Goodbye Spoiled Milk!
It's easy to forget long-lasting milk at the back of your refrigerator. But now you know exactly what to do if you doubt the soy milk’s freshness.
You can start by checking if the package is swollen or bloated. If it seems okay, look at the dates to see if it’s past the expiry period.
Once you’ve confirmed that it's not expired, open the container and sniff it to see if it has an unpleasant smell. If the milk smells okay, you can pour some of it into a clear glass for further inspection.
Fresh soy milk should be whitish with a smooth consistency.
Discard the milk if it looks yellowish or curdled. You can also grab a spoon and taste some of it. It’s better to check if it’s sour before mixing it with your coffee or cereal.
You can even heat the milk to see if it will curdle.
Remember always to refrigerate and handle the milk with care. Freezing is also a good option if you wish to preserve the soy milk for longer.
