How Long Does Cashew Milk Stay Fresh After Its Opened?

Rich in protein and minerals, cashew milk can be an advantageous alternative to cow's or goat's milk. Its mild flavor makes it ideal for baked goods, smoothies, and caffeinated beverages, but you can also enjoy it as is. Plus, it has a relatively long shelf life. 

This plant-based drink is similar to almond milk in terms of flavor, texture, and appearance. Once opened, almond milk can last for seven to 10 days in the fridge. The same goes for cashew milk, depending on its composition and packaging. Ideally, store it in the back of the refrigerator to keep it fresh for longer.

A 2021 study found that cashew milk can last for two months or longer if unopened, according to Food Science and Technology. But, as you would expect, its shelf life decreases once the packaging has been opened. After that, you have about a week or so to consume it without the risk of food poisoning.

Silk, Elmhurst, and other manufacturers of milk alternatives use Tetra Pak and HydroRelease packaging, respectively, for their cashew milk. Thanks to these technologies, their products are shelf-stable and can be safely stored at room temperature for 10 months or longer. However, once opened, they need to be refrigerated and consumed within seven to 10 days. By comparison, shelf-stable cow's milk lasts for only four to seven days in the refrigerator after opening.

The packaging of your cashew milk also matters. Bottled cashew milk can go bad in as little as three days after you open the packaging. Glass bottles are reusable but not shelf-stable. Tetra Pak cartons, on the other hand, are made of multiple layers of materials, including paperboard, polymers, and aluminum foil. This creates a barrier against light, oxygen, and moisture, preserving food quality for longer.

Additionally, commercial plant-based milk undergoes pasteurization, which can further increase its shelf-life and prevent microbial growth. For example, Silk products are ultra-pasteurized, meaning they have been heated to 280 degrees Fahrenheit or higher for at least two seconds. Similarly, UHT milk is heated at ultra-high temperatures to maintain its quality and freshness. Homemade cashew milk, however, often doesn't undergo this process and thus can go bad within three days. 

Some foods don't need an expiration date, but that's not the case with cashew milk. Ideally, use it before the "best by" date on the package to avoid food poisoning. After you open the bottle or carton, the milk is exposed to oxygen and bacteria. Refrigeration can slow down but not stop the oxidation process and microbial growth, according to Michigan State University.

Sometimes, cashew milk may develop mold, foul odors, or changes in color and texture after opening — especially if it wasn't properly stored. For example, it may turn yellow, form clumps, or become thicker. These are signs of spoilage, and you should discard the milk immediately.

If you have a larger batch of cashew milk, pour it into an airtight container or ice cube tray and store it in the freezer for three to six months. Once thawed, it may not taste as good as when fresh, but you can still use it in cooked meals and desserts. So depending on how long you plan on using that cashew milk, you now know the best way to store it.