Oat milk is a creamy alternative to dairy milk, made from whole oats and sometimes a sweetener, by extracting the plant material with water.
If you’ve bought a carton of oat milk, but it’s still hanging around in your fridge, you may ask yourself:
Has my oat milk gone bad? How long does it last?
Here’s what you need to know about the shelf-life of oat milk. A shelf-stable carton of oat milk can last 1-3 months past the best-by date on the label. Once it’s opened, you can expect it to last for 4-7 days in the fridge.
How To Tell If Oat Milk Is Bad

Check your oat milk for the following signs to determine if it has spoiled:
- Consistency: If the milk is chunky or too thick, it’s best to get rid of it.
- Color: The color of the milk may turn yellow instead of creamy white if it begins to spoil. When that happens, discard it.
- Smell: Give your milk a good sniff before drinking it. If it smells sour or off, throw it out.
- Taste: If all else seems okay, give it a final taste test. If you’re pleased, you can hold onto it. If it has an off taste, throw it away.
Storing Oat Milk

When your carton is still unopened, there are two ways to store it. If it is shelf-stable oat milk, it can be stored in the pantry or countertop, provided it’s away from sources of heat.
Chilled cartons need refrigeration, so make sure to store them in the fridge even when unopened.
Once you open a carton of oat milk, it should be kept in the fridge, no matter the type.
Other things to remember include always keeping your carton sealed tightly when not in use. Pour your oat milk into a glass when drinking it so you can be aware of any changes.
Lastly, if your carton isn’t resealable, transfer the milk to a container, that is. If the carton is resealable, make sure you reseal it tightly after use. Keeping your milk away from bacteria and outside moisture is key to keeping it fresh!
How Long Does Oat Milk Last?

Shelf-stable oat milk generally lasts 1-3 months past its best-by date. Chilled oat milk will stay fresh for 5-7 days past its sell-by date. Once the carton is opened, both types last 4-7 days in the fridge.
Brands like Tōasts tend to last on the lower end, whereas brands like Oatly last longer.
Health Benefits Of Oat Milk

Oat milk is often fortified with nutrients like vitamins A, D, B2, and B12, as well as minerals like calcium. It is vegan and free of lactose, soy, and nuts. So if you follow a plant-based diet, are lactose intolerant, or have a nut or soy allergy, this is ideal for you.
It may help lower blood cholesterol as it is high in beta-glucans – a soluble fiber that benefits heart health. Lastly, oat milk is fortified with calcium and vitamin D, which benefits bone health.
The Bottom Line On Oat Milk
This plant-based milk option is more eco-friendly as it takes about six times less water to produce a carton of oat milk compared to almond milk.
Oat milk can last a good amount of time if stored correctly.
Remember to keep shelf-stable cartons of oat milk at room temperature when unopened and to store chilled cartons of milk in the fridge when unopened.
As soon as you open your oat milk to enjoy, make sure to check it for any signs of spoilage by pouring it into a separate glass.