How Long Does Cornstarch Last?
Fine white powder made from corn, used as a thickening agent in sauces, gravies, and baking.
The Short Answer
At room temperature in the pantry, expect 1825– days under normal conditions. These times are based on USDA food safety guidelines and assume proper storage conditions.
Storage Times at a Glance
Source: USDA FoodKeeper | Last verified: March 26, 2026 | Our methodology
Cornstarch is essentially immortal if kept dry. It is a pure starch with no oils, proteins, or moisture to degrade. That container from three years ago in the back of your pantry is perfectly fine as long as no moisture has gotten in.
How to Store Cornstarch
Store in a cool, dry place in an airtight container. Moisture is the only real threat to cornstarch. If it gets wet, it clumps and loses its thickening ability. Keep the container sealed tightly and use a dry measuring spoon.
How to Tell if Cornstarch Has Gone Bad
Look for these signs that cornstarch has spoiled: cornstarch does not truly expire if kept dry. discard if it has absorbed moisture (visible clumps that do not break apart), has an off smell, or shows signs of insect activity.
The Professor's rule: When in doubt, throw it out. No meal is worth food poisoning.
The Bottom Line
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.
Frequently Asked Questions
Not in a meaningful way. Dry cornstarch stored properly lasts indefinitely. The date on the package is a quality suggestion. If it is dry, free of clumps, and smells neutral, it is good to use regardless of the date.