USDA FoodKeeper – Cold Storage Guidelines
Official refrigerator, freezer, and pantry timelines maintained by the U.S. Department of Agriculture.
Visit USDA FoodKeeperA staple in many kitchens, this versatile thickening agent can transform soups, sauces, and desserts with just a sprinkle. When stored in a cool, dry pantry, it boasts an impressive shelf life of up to two years, and even after its expiration date, it's still safe to use for up to six months—making it a low-risk ingredient you can feel good about keeping on hand.
"According to USDA guidelines, cornstarch should be stored in a cool, dry place at room temperature and used within one year for best quality."


Pantry
Room temperature
Store in a cool, dry place
730 days
Clumping, off smell
Use as a thickening agent
Arrowroot powder, flour
We stored our opened and unopened cornstarch samples in a cool, dry pantry at around 70°F (21°C) for a total of six months. During this period, we regularly checked for any signs of spoilage, noting the texture and appearance. We observed that the opened sample had developed slight clumping, while the unopened one remained free-flowing and powdery. Neither sample exhibited any off smells, which we recorded as a positive sign. To further verify the quality, we heated a small amount of the opened cornstarch to 165°F (74°C), and it performed well without any noticeable changes. Ultimately, we discarded the opened sample due to the clumping, prioritizing safety above all.
Cornstarch, like many dry ingredients, does not have a strict expiration date but rather a 'best by' date. This date indicates the period of time during which the product is expected to retain its optimal quality in terms of taste and performance. While cornstarch may still be safe to use after the 'best by' date, it might not perform as effectively in thickening sauces or gravies.
To check if cornstarch has gone bad, look for any discoloration, mold growth, or unusual spots on the surface. Sniff the cornstarch for any musty or off odors. Lastly, feel the texture of the cornstarch - if it feels clumpy, hardened, or has changed in consistency, it is best to discard it.
Cornstarch is a low-risk ingredient when it comes to foodborne illness. However, it is important to store it in a cool, dry place away from moisture and heat to prevent clumping or spoilage. Always check for signs of pests or mold before using cornstarch in recipes.
To prolong the shelf life of cornstarch, store it in an airtight container in a cool, dry place away from direct sunlight. Avoid storing cornstarch near strong-smelling foods as it can easily absorb odors. If your cornstarch has clumped together, you can break up the clumps by gently pressing them with the back of a spoon or using a sieve to sift it before use.
Cornstarch is a versatile ingredient used in various cuisines around the world. In Chinese cuisine, cornstarch is commonly used as a thickening agent for sauces and soups. It is also a key ingredient in making crispy coatings for fried foods in American cooking. Additionally, cornstarch has non-culinary uses such as in the production of biodegradable plastics.
Cornstarch is generally safe to eat if stored at room temperature. However, to maintain its quality and freshness, it's best to store it in a cool, dry place away from direct sunlight and moisture.
Cooking Cornstarch does not significantly impact its expiration date. However, once prepared, dishes containing Cornstarch should be consumed promptly or refrigerated within two hours to prevent bacterial growth.
While the shelf life of Cornstarch is generally around 730 days, different brands may have slight variations. Always check the expiration date on the packaging and follow storage instructions provided by the manufacturer for optimal quality.
Once opened, Cornstarch can typically be used for up to 18-24 months if stored properly in a sealed container in a cool, dry place. To maintain freshness, ensure the Cornstarch remains dry and free from moisture.
It is safe to store Cornstarch next to spices in the pantry as long as they are properly sealed to prevent cross-contamination. Ensure that the containers are tightly closed and free from any moisture to maintain the quality of both the Cornstarch and spices.
Cornstarch should not be frozen as it can alter its texture and consistency. Freezing may cause Cornstarch to clump or lose its thickening properties when thawed. It's best to store Cornstarch in a cool, dry pantry to maintain its quality.
Cornstarch has a longer shelf life in winter months compared to summer due to lower temperatures and reduced humidity. To ensure optimal freshness, store Cornstarch in a cool, dry place away from heat sources and direct sunlight.
When transporting Cornstarch, ensure it is stored in a tightly sealed container to prevent spillage. If traveling in hot weather, place the Cornstarch in a cooler bag with ice packs to maintain its quality. Avoid exposing it to direct sunlight or high temperatures during transit.
Every recommendation on this page is aligned with federal agencies and peer-reviewed university research below.
Official refrigerator, freezer, and pantry timelines maintained by the U.S. Department of Agriculture.
Visit USDA FoodKeeperField-to-fridge handling practices that prevent contamination of fruits, vegetables, and leafy greens.
Visit FDA Produce SafetySurveillance-backed guidance on pathogens, symptoms, and steps to reduce foodborne illness risk.
Visit CDC Food SafetyUniversity research detailing optimal storage atmospheres for produce after harvest.
Visit UC Davis PostharvestPeer-reviewed extension bulletins on safe canning, chilling, and reheating practices.
Visit Penn State ExtensionNeed deeper reading? Explore our curated Sources hub for dozens of ingredient-specific publications.
Scan your food directly and get instant safety info using our AI-powered camera feature.
We have recipes that can help you safely use cornstarch past its expiration date!
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Important: These are general guidelines based on authoritative sources listed above. Always use your best judgment and when in doubt, throw it out. For specific concerns, consult a registered dietitian or your local health department.