If you assume that soy milk can never go bad because it contains no dairy, you might want to read on. Many assume because soy milk is plant-based, it will stay safe for years. You might not even hesitate to grab the opened soy milk carton that sat out on the counter overnight. But is this really safe? Does soy milk go bad? And how do you tell when it should be dumped down the drain? 

Here’s what you need to know:

Does soy milk go bad? 

Yes. Soy milk can go bad and the indicators or actually pretty similar to those of spoiled cow’s milk. You can pick up on a sour odor and a thicker consistency. If either of these are present, it’s probably time to toss. 

Soy milk should be slightly off-white in color and perfectly smooth. If you’re unsure of your soy’s current status, try pouring it into a glass. If you look and see lumps, it’s definitely gone bad. 

You may also be able to tell if your soy milk has gone sour by checking the carton. As soy milk expires, the carton may appear bloated. The expansion is the result of bacteria releasing gas. 

How long is it safe to drink?

Soy milk must be refrigerated once opened. A carton will typically last 7-10 days when stored properly. Products can sometimes last longer, but you’ll need to rely on the sniff or pour test to determine safety. 

Unrefrigerated soy milk — the kind you buy alongside canned goods — can last a long time when stored in the pantry unopened. Check the expiration date, but some products will stay safe for as long as eight months. 

What happens if you drink bad soy milk?

Drinking bad soy milk is similar to drinking bad cow’s milk — or eating many other expired foods, for that matter. You are likely to experience symptoms associated with food poisoning including nauseas, an upset stomach, and possibly even vomiting. 

What to do with soy milk that’s about to go bad?

If you have soy milk that you need to use up in a hurry, don’t worry! Soy milk is easy to throw in cereal, smoothies, or use as coffee creamer or in pancake batter. Try churning soy milk into vegan-friendly ice cream, or adding probiotics to turn it into vegan yogurt. For a cool treat, try blending a bit of orange juice with soy milk and stevia and freezing in a popsicle mold for a tasty vegan creamsicle.

4 Ingredient Soy Creamsicles


  • 1 cup soy milk
  • 1 cup orange juice
  • 2-3 tbsp agave or stevia
  • 1/2 tsp vanilla extract


1. Add all ingredients to a blender and puree until combined.

2. Pour mixture evenly into popsicle molds. Insert the popsicle stick and freeze for about 4 hours. 

3. When ready to serve, run mold under hot water for a few seconds to help release the popsicles. 

4. Enjoy!