Soy milk is created by soaking and grinding soybeans. This mixture is then boiled and filtered to remove large particles of soybeans. It is created as a natural by-product of the tofu manufacturing process.
It is a type of liquid known as a stable emulsion. This means it is a combination of protein, oil, and water that does not separate.
In the later 20th century soymilk became more popular in the Western world, building on its popularity in Eastern Asia. It has been manufactured and developed to mimic the taste and consistency of dairy milk and is a popular substitute.
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How to store soy milk
When unopened, this depends on where in the store you purchased the soy milk from. If you purchased it from an ambient shelf, you can store the soy milk in a cool, dry place such as a cupboard.
If you purchased the soy milk from the refrigerator, even unopened this should still be kept cold in the refrigerator.
Once you have opened the carton of soy milk it must be stored in the refrigerator at all times. We suggest keeping them in the middle of the fridge, away from the door. This will have the most consistent temperature and will help to keep the soy milk fresh for longer.
Homemade soy milk should also be kept in the refrigerator at all times.
Can you freeze soy milk?
Yes, you can. It is not recommended as the milk’s consistency and texture can be affected by the freezing and thawing process.
We recommend freezing your soy milk in individual serving portions as this will prevent you from defrosting an excess of soy milk. It cannot be refrozen once thawed and so you should only defrost what you will use on the same day.
Pour the soy milk into an ice cube tray to nearly the top of the holes. It is important to leave a small gap at the top as liquids expand when they freeze. This gap will prevent the soy milk from overflowing and making a mess of your freezer.
Place the ice cube tray level in your freezer and leave it overnight to freeze solid. The next morning, remove the ice cube tray from the freezer and pop out the soy milk cubes.
Transfer the soy milk cubes to a freezer-safe ziplock bag and label with the date frozen and what the cubes are made from. A standard ice cube tray makes 2 tablespoon cubes, and it is a good idea to write this information on the bag too.
How long does soy milk last?
Unopened, soy milk tends to last for anywhere between 8 months up to a whole year from the date of manufacturing. The date label on soy milk tends to be a ‘best before’ rather than ‘use by’. This means that the milk is not unsafe to consume after this date, but may have reduced in quality.
Long-life soy milk will likely be safe for consumption for a few weeks to a couple of months after the date on the packaging. For refrigerated soy milk, it will likely keep for a week or two past the use-by date.
Once you have opened the soy milk container, you can keep it in the refrigerator for up to 2 weeks. If it is not stored correctly, the milk will perish much faster.
Homemade soy milk contains no preservatives and will go off much faster than commercially manufactured versions. This tends to only keep for up to 5 days once it has been made.
How do you tell if soy milk has gone bad?
The first sign that your soy milk has gone off is if the carton has puffed out. This is because the bacteria contained within the milk is reacting and releasing gas, usually carbon dioxide. This will make your soy milk carton appear bloated. This is an easy indicator of whether your milk has perished.
The next thing to check is the smell, similarly to how you would check regular dairy milk. Fresh soy milk does not have much of a smell. If you can smell a strong and unpleasant odor once the carton has been opened this is a fairly clear indication that you should not drink it.
You should then check the consistency of your soy milk as you are pouring it. If you notice any mold, lumps, or curds, do not drink the milk. Additionally, if there is a strange change in consistency, i.e. the milk is thick and gloopy, this also indicates the soy milk has decayed.
Other notes
Do not drink soy milk directly from the carton, instead, you should pour it into a bowl or glass. This is because bacteria from your mouth can easily make their way into your soy milk if you drink from the carton.
This can cause your milk to spoil much faster and could potentially cause food poisoning or diseases to spread if multiple people are drinking from the same carton.
If you are using an ice cube tray to freeze soy milk, we recommend measuring the volume of each cube before pouring in the soy milk.
Summary
Soy milk has a long shelf life when the container is unopened. The ideal storage method varies depending on what type of soy milk you have. The length of time it will keep for is also dependent on the type of milk.
Long-life soy milk can last for up to a year when it’s unopened and can last for up to 2 weeks when opened. Refrigerated soy milk will last usually around 2 weeks past the stated best before date. Homemade soy milk has the shortest lifespan, due to the lack of preservatives included in the recipe.
There are a few clear and easy ways to tell if your soy milk has gone bad. You should rely on your senses of smell and sight to see if it is still safe for human consumption.
