How Long Does Powdered Sugar Last?
Finely ground sugar with a small amount of cornstarch added to prevent clumping, also called confectioners' sugar.
The Short Answer
At room temperature in the pantry, expect 730– 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
If your powdered sugar has gotten lumpy from moisture, push it through a fine mesh sieve before using. Small lumps break up easily. If it has hardened into a solid brick, it has absorbed too much moisture and the texture may not work for frostings.
How to Store Powdered Sugar
Store in a cool, dry place in an airtight container or in the original bag inside a sealed container. Powdered sugar absorbs moisture and odors from the air easily. Keep away from strong-smelling foods.
How to Tell if Powdered Sugar Has Gone Bad
Look for these signs that powdered sugar has spoiled: powdered sugar does not truly spoil if kept dry. discard if it has absorbed moisture (hard lumps that do not break apart), has an off smell from absorbing odors, or shows 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 really. Dry powdered sugar stored in an airtight container lasts indefinitely. The main risk is moisture absorption and odor absorption, not spoilage. If it smells neutral and is free of pests, it is safe to use regardless of the date on the package.