Similar to dairy milk, if it looks funky or smells bad, those are two surefire warning signs your carton of almond milk belongs in the trash. “Signs of spoilage include discoloration or foul odor. It can get lumpy or develop specks of mold,” registered dietitian nutritionist Dana Angelo White told Food Network in a discussion about safe almond milk consumption. “Bottom line: when in doubt, toss it!”
Another indicator that a carton of almond milk is no longer safe to drink is if too much time has passed since opening. Refrigerated homemade almond milk should only be allowed to hang around for three days. Meanwhile, refrigerated commercial almond milk can be kept for ten days after popping the top. But don’t use the expiration date stamped on your milk carton to determine this timeline. Expiration dates are synonymous with “best by” or “sell by” dates, which is in reference to product quality — not safety.
Another way to tell if your almond milk has spoiled is to use the coffee cup trick. Upon pouring a splash of almond milk into a hot cup of joe, spoiled almond milk will curdle on the surface, explains Good Housekeeping. Right away, you’ll be able to spot small, itty bitty chunks floating around. If almond milk has started curdling on its own in the container, this is also a sign that it’s unsafe to drink.