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Does Oat Milk Go Bad? If Yes, How Long Does It Last? 

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I daresay that oat milk is my favorite plant-based milk and I simply can’t imagine my life without it. (This is not an over-exaggeration.) Out of fear that I’ll open the fridge in the morning without seeing oat milk waiting for me, I usually buy more than I need at the moment.

Guess what happens when you have one too many oat milk cartons in your pantry, fridge, and freezer? You start worrying that one of these has probably gone bad. 

And then you ask yourself: 

Does Oat Milk Go Bad?

female hand pouring oat milk in a glass

Well, oat milk certainly can’t last forever because it has an expiration date (we’ll go in-depth on that matter below). Oat milk does go bad after a certain period of time but this depends on whether it is opened, unopened, and where it is stored, which brings us to the next important section. 

How Long Does Oat Milk Last?

Is your oat milk store-bought, homemade, opened, unopened, and where is it stored? According to the USDA, a carton of oat milk or any other perishable food shouldn’t be left for more than 2 hours at room temperature. Different rules apply if you keep oat milk in the refrigerator, or in the freezer. 

Let’s see the shelf life of store-bought oat milk in the table below:

The counter (room temperature)Opened2 hours
The counter (room temperature)Unopened2 hours (if not shelf-stable)
The counter or the pantryUnopened (shelf-stable)6 months - 1 year
FridgeOpened7 - 10 days
FridgeUnopened2 - 3 weeks
FreezerUnopened/in an airtight containerUp to 6 months

As expected, homemade oat milk has a shorter shelf life, as seen in the table below:

FridgeUp to 5 days
FreezerUp to 3 months (in an airtight container)

Is It Safe To Consume Oat Milk Past Its Expiration Date?

I know, I know. Consuming food after its expiration date has been generally considered a big no-no. So, the majority of people will say that consuming oat milk (or any other food) past its expiration date is a risky endeavor. 

Sometimes it is, but in most cases, it isn’t. What if I tell you that oat milk is safe to consume 5 – 7 days past the printed expiration date if it hasn’t gone bad? 

Let’s debunk the myth of expiration dates. We have sell-by dates, best if used by, best before, and use-by dates. Here’s what every single of these labels actually means:

• Sell-by dates: These dates are more focused on the retailer instead of the consumer. In other words, a sell-by date lets the retailer know how long they should keep their product on shelves. This means that oat milk will still be safe to consume a few days after the sell-by date. 

• Best before / best if used by: This date refers to the quality of a product. It indicates that the product’s texture or taste may be slightly different after this date. In other words, oat milk is still safe to consume after best before or best if used by dates.

• Use-by dates: This date is the last recommended date for using a product regarding its quality as stated by the manufacturer. Safety won’t be compromised. This “rule” doesn’t apply to infant formulas because they shouldn’t be used after use-by dates. 

NOTE: It’s safe to consume oat milk a few days past the printed expiration date if the milk isn’t spoiled. More on that below. 

How To Tell If Oat Milk Has Gone Bad

oat milk in glass bottle with straw

To determine whether oat milk has gone bad, you need to look for any changes in smell, texture, and color. Here are the signs of milk spoilage indicating that oat milk has gone bad and you should throw it away: 

• Unusual smell: Oat milk that isn’t spoiled has a neutral, slightly sweet smell. If it has a sour, or vinegar-like smell, then you know it has gone bad. Take no chances, but toss it. 

• Changes in texture: Oat milk has a liquid consistency just like regular milk. You’ll know that it is spoiled if it has a thick, lumpy, or slimy texture. 

• Changes in color: Normally, oat milk is white to beige in color. If you notice that it is more yellow in color or there are green or yellow spots of mold, then you know it’s spoiled. 

Trust your nose and eyes because they never lie! 

What Will Happen If You Drink Spoiled Oat Milk?

Okay, let’s say that you drank spoiled oat milk because you couldn’t determine whether it was bad or not. Or because you didn’t want to discard a spoiled carton of oat milk even though you assumed that it was spoiled. 

In that case, you may experience nausea and stomach problems such as vomiting and diarrhea. In some severe cases, people also experience fever. 

If you drink oat milk that has gone bad, you can wait for a day or two for your stomach to recover. If it doesn’t, then it’s best to see your doctor. Well, you can visit your doctor right away if your food poisoning symptoms become severe.

7 Tips For Storing Oat Milk To Keep It Fresh For Longer

If you want to make sure that you’ve stored oat milk the right way in which their freshness will be intact, then follow these tips:

1. Store oat milk in the coldest compartment of your fridge. This is usually the bottom. 

2. Oat milk should be stored in the fridge at a temperature between 33°F to 40°F.

3. The ideal fridge temperature for oat milk is 37°F. The same applies to almond milk.

4. Keep oat milk in an airtight container if you want to prolong its shelf life in the fridge or in the freezer. 

5. You can also store shelf-stable oat milk in an airtight container to increase its shelf life. 

6. Keep oat milk away from sources of light or heat because this may decrease its shelf life. 

7. If you’re sure that you won’t consume opened oat milk in the next 7 to 10 days, then it’s best to freeze it. (More on this below.)

Freezing And Thawing Oat Milk

photo of oat milk in a glass

Now that you know how long oat milk lasts in different storage settings, and how to keep it fresh for longer, it’s time to also learn a thing or two about freezing and thawing it. 

How to freeze oat milk

The best freezing method for oat milk is in an airtight container. You can also freeze it in ice cube trays and use it later for coffee. Another freezing method is freezing oat milk in the carton but this method is not recommended (see below why). 

• An airtight container (recommended)

Measure the desired amount of oat milk that you plan to freeze. Keep in mind that freezing oat milk in small portions is recommended so that its consistency remains intact once thawed. 

Label your airtight container and add the date so that you know for how long you can keep it in the freezer. Also, consider adding the best-before date on the label. 

• Ice cube trays (ideal for coffee)

Measure the desired amount of oat milk that you plan to freeze for coffee. Fill the ice cube trays with oat milk. (NOTE: one ice cube tray is equivalent to 1 ½ – 2 tbsp). 

Place the ice cube tray in the freezer for approximately 2 hours. Once oat milk cubes are frozen, place them in a Ziplock freezer bag, or an airtight container. Take as many ice cubes as you need and put them in your hot coffee. 

• In the carton (not recommended)

Just throw the unopened oat milk in the freezer. 

NOTE: Freezing oat milk in the carton is not recommended because the carton is not freezer safe. As your oat milk freezes, the carton may start expanding which can result in splitting and cracking. If that happens, you will have to repack oat milk in an airtight container. 

REMINDER: You can freeze oat milk for up to 6 months if it is store-bought. Homemade oat milk should be frozen for no longer than 3 months. 

How to thaw oat milk

Place the oat milk in the fridge and allow it to thaw for a few hours. Once thawed, whisk it to retain its original consistency. 

Sometimes, thawed oat milk can have a grainy texture which can be a problem if you’re using it for coffee. However, if you’re using thawed oat milk for cooking or baking, then you won’t even notice the difference. 

NOTE: You should use thawed oat milk within the next 2 to 3 days.

Key Points

Given that I’m not a fan of those boring conclusions that start with something like “I hope I helped you learn everything you need to know about…”, I’ll take a different approach.

Here are some of the key points that may come in handy if you don’t have time or don’t want to read an entire blog post, which is totally fine by me:

• Yes, oat milk can go bad.

You can keep opened store-bought oat milk for 7 to 10 days in the fridge. Unopened store-bought oat milk should be kept for 2 to 3 weeks in the fridge. You can keep store-bought oat milk for up to 6 months in the freezer.

• Store-bought oat milk is safe to consume 5 – 7 days past the printed expiration date if it hasn’t gone bad.

You know oat milk has gone bad if it has an unusual smell, thick and slimy texture, and if it is more yellow in color with spots of mold.

If you drink spoiled oat milk, you may experience nausea and stomach problems such as vomiting and diarrhea. 

• The ideal storage method for oat milk is in the fridge at 37°F.

Freezing oat milk is best done in an airtight container, and thawing is best done in the fridge. 

Thank you for your attention.

See also: How Long Does Oatmeal Last In The Fridge?- Cooked One

Does Oat Milk Go Bad If Yes, How Long Does It Last