If plant-based milk is the mode of the moment, oat milk is the master medium. Alternative milks of all kinds provide a great option for those who favor a dairy-free diet—whether for environmental or health reasons—a fact that finds roots, nuts, fruits, and grains transforming into creamy substitutes.

Plant-based milks are also notoriously easy to whip up yourself. Alternatives like oat milk require very few ingredients, minimal prep, and are simple to adjust to your needs and tastes. A downside to this DIY approach? These homebrewed beverages come with no regulations or sell-by dates to indicate the remaining shelf life.

So, does oat milk go bad? And how can you tell? We asked a registered dietitian—and got some tips on how to make the popular option last as long as possible.

Does Oat Milk Go Bad?

Oat milk does, indeed, go bad—but the grain-based option does enjoy a longer life in the refrigerator than other plant-based milks.

“If stored properly, oat milk can last up to 10 days in the fridge once it’s been opened,” says Amy Gorin, RD, a plant-based registered dietitian and founder of Plant Based with Amy.

And you’ll want this milk to last—it has a devoted fanbase for a reason. “Oat milk is very creamy and works well in smoothies and lattes,” says Gorin. “In one cup, you get 45 calories, 1-2 grams of protein, and 1-3 grams of fiber, as well as vitamin A, vitamin D, vitamin B12, riboflavin, and calcium.”

How to Tell If Oat Milk Is Expired

Use your senses and your best judgment to determine if your oat milk is safe to drink. “If the milk smells or tastes off or looks strange when you pour it into a glass, don’t drink it,” advises Gorin.

What’s the Best Way to Store Oat Milk?

Whether you purchase your oat milk or craft it yourself, the rules of storage remain the same.

First, ditch the door and store your oat milk toward the back of the refrigerator where the temperature is the lowest. And don’t forget the air-tight container! A well-secured seal will ensure maximum freshness (and enjoyment).

The Takeaway

A mainstay at coffee shops and in many kitchens, oat milk is here to stay. The well-loved (and dairy-free) milk alternative can last up to 10 days in the fridge when properly stored in an air-tight container.

Worried that your oat milk may have spoiled? Use your best judgment and dump the beverage into your compost pile.