Ketchup

The answer

Opened ketchup lasts 6 months in the fridge.

How long it keeps

Fridge (40°F) 6 months safe window
Freezer (0°F) Do not freeze best quality
Room temp Brief table use is fine then discard
Discard Discard if it smells yeasty or fermented, bubbles, or shows mold at the cap.

By state & packaging

State Fridge Freezer
Opened, refrigerated 6 months
Unopened, pantry

Signs it has gone bad

Yeasty or fermented smell
Bubbling or hissing on opening
Mold around the cap

FAQ

Does ketchup really need refrigeration?

After opening, yes — for quality and to reach the 6-month window. Restaurant table bottles turn over too fast to matter.