The Tell-Tale Sign That Your Oat Milk Has Gone Bad

Oat milk has a lot in common with its dairy-based cousin. Oat milk makes good ice cream, is delicious in a cup of cold brew (this writer's go-to order at any coffee shop), and can go bad, just like cow milk. The indicators of expired dairy milk include a horrible strong smell, a sourer taste, a clumpy texture, and a yellow tinge to the milk's color. Turns out, these indicators are also ways to tell if your oat milk has turned for the worse.

Your nose knows if oat milk has spoiled. Smelling the milk is the best way to tell if you should throw out the carton. Good oat milk has a subtly sweet aroma that turns sour when the milk turns bad. If you don't smell anything amiss but suspect that the oat milk is no longer good to use, shake the carton and then pour a small amount into a clear glass. Much like dairy milk, oat milk will also take on a gross yellowish hue and chunky appearance.

To maintain the proper life of a carton of oat milk, make sure to follow correct guidelines for storage. Oat milk should be refrigerated upon opening, whether purchased from the dairy case or as a shelf-stable milk. Oat milk can keep anywhere from five days if homemade to three weeks if store-bought when properly refrigerated. Meanwhile, oat milk left out on the kitchen counter will only stay good for a few hours.

Oat milk does come branded with an expiration date, or a "best by" date (caveat: An expiration date and a sell by date are two different things). Be mindful of this date, as your oat milk will not last much longer than this deadline. To be completely safe, even an unopened carton should likely be discarded after a week past its "best by" date. That said, every oat milk product is manufactured a little differently, so be sure to smell the milk first if you suspect that it may have gone sour.

Oat milk is a tasty non-dairy substitute for cooking, to add to cereal, or just to drink it from a glass. There are a wealth of grocery store oat milks to try if you're curious.