Miso Per USDA FoodKeeper
On the counterCounter
2 hours
1 hour if above 90°F
In the fridgeFridge
1 year
at or below 40°F (4°C)
In the freezerFreezer
Not recommended
texture or safety suffers
Quick answer
Yes. Miso lasts 1 year in the fridge. After that, or sooner if stored badly, it spoils: watch for the signs below.
How to tell if miso is bad
Smell
Sour, yeasty or 'off' instead of how it smelled when cooked.
Texture
Slimy film, or liquid separating where it should not.
Colour
Dull or darkened patches, or any discoloured spots.
Mould
Any fuzzy growth — discard the whole container, not just the spot.
Miso past the expiration date
Best-by and sell-by
FoodKeeper gives unopened miso 1 year 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.
Past the date
For perishable miso, the storage clock matters more than the label: if it has been in the fridge longer than 1 year, discard it even before the printed date.
How to keep miso fresh longer
- Refrigerate within 2 hours of cooking (1 hour above 90°F) in shallow, airtight containers.
- Keep the fridge at or below 40°F (4°C); the door shelf is the warmest spot.
- Reheat leftovers to 165°F (74°C) and only reheat what you will eat.
More about miso
FAQ
How long does it take for miso to go bad?
1 year in the fridge, per USDA FoodKeeper. At room temperature, 2 hours.
Can miso expire?
FoodKeeper gives unopened miso 1 year 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 miso?
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 miso from going bad?
Refrigerate within 2 hours of cooking (1 hour above 90°F) in shallow, airtight containers.
Numbers on this page come from USDA FoodKeeper and FSIS guidance. Last verified November 2026. How we verify our data · Report a wrong number