How long does formula last?
In the fridge, formula keeps for 1 day after opening. Once opened, use it within 1 day.
No guideline
1 day
after opening
1 day
in the fridge unless noted
Does formula go bad?
Yes. The fridge time above is the window USDA gives for good quality; after it, formula may still be safe for a short while but quality drops and spoilage signs start. The date on the package is the maker's quality promise; the times here count from purchase unless marked "from the package date".
Two numbers to keep in mind: a fridge at 40 F (4 C) or below, and no more than 2 hours at room temperature (1 hour above 90 F / 32 C) for anything perishable.
How to tell formula has gone bad
General signs for baby food, the group USDA lists formula under.
- Lid pops or bulges when you open the jar
- Sour or off smell instead of the usual mild scent
- Colour looks darker or duller than a fresh jar
- Watery separation that will not stir back together
- Mould spots on the surface or under the lid
More on baby food. The times above are quality guidelines, not safety limits; food that shows these signs goes out regardless of the date.
How long do other baby food last?
Source: USDA FSIS FoodKeeper dataset (public domain). How we decode the data.