Per USDA FoodKeeper
On the counterCounter
2 hours
1 hour if above 90°F
In the fridgeFridge
1–2 days
at or below 40°F (4°C)
In the freezerFreezer
Not recommended
texture or safety suffers
On the counterCounter
Not recommended
keep it cold
In the fridgeFridge
1 week
at or below 40°F (4°C)
In the freezerFreezer
Not recommended
texture or safety suffers
Quick answer
Yes. Kefir lasts 1–2 days in the fridge. After that, or sooner if stored badly, it spoils: watch for the signs below.
How to tell if kefir is bad
Smell
Sour or cheesy smell when it should be clean and mild.
Texture
Lumps, curdling or a thick, slimy body.
Colour
Yellowing or a pink, green or grey tinge.
Taste
Sour or bitter at the first sip — stop and discard.
Kefir past the expiration date
Unopened
FoodKeeper gives unopened kefir 1 week in the fridge, counted from the day you buy it. "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 1–2 days in the fridge from the day you open it.
How to keep kefir fresh longer
- Store on an inside shelf, not the door, at 40°F (4°C) or below.
- Close the container tightly; dairy absorbs fridge odours.
- Pour what you need and return it to the fridge right away.
More about kefir
FAQ
How long does it take for kefir to go bad?
1–2 days in the fridge, per USDA FoodKeeper. At room temperature, 2 hours.
Can kefir expire?
FoodKeeper gives unopened kefir 1 week in the fridge, counted from the day you buy it. "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 kefir?
Spoiled perishable food can cause food poisoning: nausea, vomiting, cramps or diarrhoea. See a doctor if symptoms are severe or last more than a few days.
How do you keep kefir from going bad?
Store on an inside shelf, not the door, at 40°F (4°C) or below.
Numbers on this page come from USDA FoodKeeper and FSIS guidance. Last verified November 2026. How we verify our data · Report a wrong number