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Clean Pantry

Does Oat Milk Expire?

This popular non-dairy milk might not be as fickle as cow's milk, but you should still check the date on the carton.

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If you’re vegan, sensitive to dairy, or just love a good latte, chances are oat milk is a frequent resident in your kitchen. And why not? There’s plenty to love. Oat milk is lower in fat and cholesterol than cow’s milk and offers much more fiber, which is better for digestive health and will keep you full longer. Additionally, since it contains no lactose, dairy, soy, or nuts (and depending on which brand you buy, it might be gluten-free, too), you’re evading a slew of allergens. 

However, when you’re sticking your eyes or nose up to the opening of a carton, determining whether oat milk is fresh or spoiled can be challenging. Here’s the lowdown on the signs and risks of spoiled oat milk, how long oat milk lasts in the fridge, pantry, and freezer, and how to store oat milk to keep it fresher longer. 

Does Oat Milk Go Bad?

Although oat milk tends to last longer than cow’s milk and other alternative milks, it does go bad. 

How to Tell If Your Oat Milk Has Expired

“Different brands of oat milk are manufactured surprisingly differently and can behave in various ways,” says Mariana Marinho, co-owner of Vaca’s Vegan Creamery in Chicago. “A good general rule is to trust your nose and palate, and to look for signs of change in texture and color.” 

Telltale signs of spoiled oat milk include: 

  • A musty or sour, somewhat vinegary smell
  • Changes in appearance such as lumpiness, sliminess, separation, and/or congealment
  • Discoloration

“Safe oat milk will have a neutral, slightly sweet smell that will turn musty and sour when spoiled,” says Kelsey Lorencz, RDN and nutrition advisor for Fin vs Fin. “The appearance of oat milk should be creamy and white to beige in color. Spoiled oat milk can be lumpy, slimy, more yellow, or have spots of mold that appear yellow to green and could even be fuzzy.” 

Juliana Tamayo, RD, MS, recommends shaking your oat milk and pouring it in a glass for a closer look and full smell. 

Are There Risks?

If your carton of oat milk is simply past its expiration date, you should be in the clear. “But, if the oat milk has signs of spoilage or has been left out at room temperature for over two hours, it could potentially cause food poisoning, which could lead to nausea, vomiting, diarrhea, or a fever,” Lorencz says. If you aren’t certain your oat milk is still fresh, it’s best to discard it and not take any chances. 

What to Do With Spoiled Oat Milk

Oat milk showing any signs of spoilage should be discarded. If you have any suspicions, it’s best to throw it out. “While it may not make you sick 100% of the time, it’s impossible to know what type of bacteria is present, and taking the chance of food poisoning just isn’t worth it, “Lorencz says.” 

If your oat milk is past its expiration date but doesn’t show signs of spoilage, you should still be able to use it for recipes that call for oat milk, says Rusty Hansen, professional chef at Hunter’s Feast

How Long Does Oat Milk Last?

Store-bought oat milk will last for about 2-3 weeks in the refrigerator, about 5-7 days past the printed expiration date, and up to 6 months in the freezer. 

“Shelf-stable oat milk can last unopened for at least 6 months,” if not more, Tamayo says. To increase its longevity, Hansen recommends storing shelf-stable oat milk in an airtight container. 

How to Store Oat Milk to Keep It Fresh

The best way to keep oat milk fresh is to ensure that it’s cold. Store it in the coldest part of your refrigerator (which is usually the bottom), or make sure it’s stored below between 32 and 40 degrees to prevent freezing and spoiling. According to Whirlpool, the ideal refrigerator temperature is 37 degrees. 

Homemade oat milk: Store homemade oat milk in the fridge and consume it within 5 days — it will likely separate and taste bad after that, Tamayo notes. 

Store-bought oat milk: Keep store-bought oat milk in the fridge, ideally at a temperature between 33 and 40 degrees, and consume within 2-3 weeks. For even more protection, shut the lid tightly and avoid letting that carton sit on the table or countertop. “While it’s safe to leave oat milk on the counter for up to two hours at a time, it will stay safe longer if you keep it cold as much as possible,” Lorencz says.

Shelf-stable oat milk: Keep unopened oat milk in a cool, dark place, like a pantry, until you’re ready to use it. You can secure it in an airtight container to increase its lifespan. “As long as your kitchen or house isn’t too hot, your shelf-stable milk should last months if not a full year,” Tamayo says. Once it’s opened, keep it in the fridge and consume within 1-2 weeks.