Per USDA FoodKeeper
On the counterCounter
1 hour
cool, dry place
In the fridgeFridge
1 day
at or below 40°F (4°C)
In the freezerFreezer
Not listed
no FoodKeeper figure
On the counterCounter
Not recommended
keep it cold
In the fridgeFridge
Not listed
no FoodKeeper figure
In the freezerFreezer
Not listed
no FoodKeeper figure
Quick answer
Yes. Prepared baby formula lasts 1 day in the fridge. After that, or sooner if stored badly, it spoils: watch for the signs below.
How to tell if prepared baby formula is bad
Smell
Sour or off smell in prepared formula or food.
Texture
Separation that does not mix back, or clumps.
Colour
Change from the usual colour.
Seal
Jar lids that do not pop on opening, or damaged pouches — discard.
Prepared baby formula past the expiration date
Unopened
Follow the package date. "Best-by" and "sell-by" describe quality and stock rotation, not safety; only infant formula carries a federally required use-by date.
Opened
Once opened, the printed date no longer applies. Count 1 day in the fridge or 1 hour in the pantry from the day you open it.
How to keep prepared baby formula fresh longer
- Should be discarded after use-by date.
- Follow the label and your pediatrician's instructions first.
- Refrigerate prepared or opened products right away.
More about prepared baby formula
FAQ
How long does it take for prepared baby formula to go bad?
1 day in the fridge, per USDA FoodKeeper.
Can prepared baby formula expire?
Follow the package date. "Best-by" and "sell-by" describe quality and stock rotation, not safety; only infant formula carries a federally required use-by date.
What happens if you eat bad prepared baby formula?
Usually an unpleasant taste rather than illness, but discard anything mouldy, rancid or smelling off.
How do you keep prepared baby formula from going bad?
Should be discarded after use-by date.
Numbers on this page come from USDA FoodKeeper and FSIS guidance. Last verified November 2026. How we verify our data · Report a wrong number