How Long Does Oat Milk Last?
Plant-based milk alternative made from oats and water, shelf-stable before opening.
The Short Answer
Oat Milk lasts 7–10 days in the refrigerator when stored properly at 40°F or below. For longer storage, oat milk can be frozen for 3–6 months while maintaining good quality. These times are based on USDA food safety guidelines and assume proper storage conditions.
Storage Times at a Glance
Source: Manufacturer guidelines | Last verified: March 26, 2026 | Our methodology
Oat milk separates naturally, which is not a sign of spoilage. Give it a good shake before pouring. If it smells sour or has chunks that do not blend smooth when shaken, it has gone bad.
How to Store Oat Milk
Shelf-stable (aseptic) cartons can be stored in the pantry until opened. Once opened, refrigerate and use within 7-10 days. Refrigerated oat milk should stay in the fridge at all times. Shake well before each use as separation is normal.
How to Tell if Oat Milk Has Gone Bad
Look for these signs that oat milk has spoiled: sour smell, lumpy or chunky texture, mold around the cap, bloated container, off or bitter taste
The Professor's rule: When in doubt, throw it out. No meal is worth food poisoning.
The Bottom Line
Properly stored oat milk stays safe for 7–10 days in the fridge. Always store in airtight containers, refrigerate within 2 hours of purchase or preparation, and trust your senses. If something looks, smells, or feels off, discard it regardless of how many days it has been. Freezing is always an option if you will not use it within the refrigerator window.
Frequently Asked Questions
Most brands recommend 7-10 days after opening when kept refrigerated. Some brands with fewer preservatives may only last 4-5 days. Always check the specific brand's label and trust your senses.