Per USDA FoodKeeper
On the counterCounter
Refrigerate
once opened
In the fridgeFridge
1 year
at or below 40°F (4°C)
In the freezerFreezer
Not listed
no FoodKeeper figure
On the counterCounter
1–2 years
cool, dry place
In the fridgeFridge
Not needed
shelf-stable
In the freezerFreezer
Not needed
keeps without freezing
Quick answer
Yes. Mustard lasts 1 year in the fridge. After that, or sooner if stored badly, it spoils: watch for the signs below.
How to tell if mustard is bad
Smell
Fermented, yeasty or sour beyond the product's usual tang.
Texture
Separation that does not stir back, or a slimy layer.
Colour
Darkening or a change in colour at the top of the jar.
Mould
Any fuzz on the surface or lid — discard the jar.
Mustard past the expiration date
Unopened
FoodKeeper gives unopened mustard 1–2 years in the pantry, 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 year in the fridge from the day you open it.
How to keep mustard fresh longer
- Refrigeration ensures that commercial sauces and condiments stay fresh for a longer period of time. Shelf-stable commercial mustard is safe when stored at room temperature after opening. Quality, not safety, is the reason the labels on these products suggest that they be refrigerated after opening.
- Refrigerate after opening unless the label says otherwise.
- Use a clean utensil each time; crumbs and double-dipping shorten shelf life.
More about mustard
FAQ
How long does it take for mustard to go bad?
1 year in the fridge, per USDA FoodKeeper.
Can mustard expire?
FoodKeeper gives unopened mustard 1–2 years in the pantry, 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 mustard?
Usually an unpleasant taste rather than illness, but discard anything mouldy, rancid or smelling off.
How do you keep mustard from going bad?
Refrigeration ensures that commercial sauces and condiments stay fresh for a longer period of time. Shelf-stable commercial mustard is safe when stored at room temperature after opening. Quality, not safety, is the reason the labels on these products suggest that they be refrigerated after opening.
Numbers on this page come from USDA FoodKeeper and FSIS guidance. Last verified November 2026. How we verify our data · Report a wrong number