How Long Does Ketchup Last?

How long does opened ketchup last in the fridge?

Opened ketchup lasts about 6 months in the refrigerator, though the printed instructions on most bottles recommend 1-2 months for best quality. The combination of vinegar (about 4-5 percent acidity, pH around 3.5-3.9), sugar, salt, and tomato makes ketchup naturally hostile to bacterial growth. Quality changes happen before safety becomes an issue: the color darkens from bright red to brownish-red over time, and the flavor loses its bright, tangy notes as the vinegar oxidizes. Store on a refrigerator shelf rather than the door for more stable temperature; doors run 5-10 degrees warmer than shelves on average. Squeeze bottles last the same time as glass bottles if stored properly. Specialty ketchups (organic, low-sugar, sugar-free) may have shorter fridge lives of 3-4 months due to less acid or sugar.

How long does unopened ketchup last?

Unopened ketchup lasts 1 year past the printed best-by date when stored in a cool, dark pantry below 75 degrees F. The commercial bottling process essentially preserves the ketchup until the seal is broken. Glass bottles tend to last slightly longer than plastic because plastic can allow tiny amounts of air to penetrate over years, slowly degrading color and flavor. Once opened, the clock starts on the refrigerator timeline regardless of how recently you bought the bottle. Restaurant-size or warehouse-club ketchup bottles last just as long as individual portions when unopened, but should be transferred to smaller containers once opened to limit air exposure. Single-serve ketchup packets last about 9-12 months past the printed date in any cool storage.

Does ketchup need to be refrigerated?

No, ketchup doesn't strictly need refrigeration for safety, though the manufacturer's label says to refrigerate after opening for quality reasons. At room temperature, opened ketchup lasts about 1 month before flavor and color quality decline noticeably; refrigerated ketchup lasts about 6 months. The high acidity makes botulism and most foodborne pathogens unable to grow even at room temperature. Restaurants typically leave ketchup at room temperature on tables because individual bottles get used quickly enough that quality decline isn't an issue. For home use, refrigerating extends the usable life significantly and is the standard recommendation. If you go through ketchup quickly (within 2-4 weeks of opening), the cabinet is fine; for longer storage, the fridge is better.

How do you tell if ketchup has gone bad?

Spoiled ketchup shows several signs. The color shifts from bright red to dark brown or brownish-red; watery separation appears where clear liquid pools on the surface and won't mix back when squeezed; the smell turns sour, fermented, or fizzy rather than sweet and tangy; and active bubbling or fizzing when the bottle is opened indicates fermentation. Visible mold (uncommon but possible around the bottle's rim or under the cap) means immediate disposal. Most ketchup degradation is quality-related rather than safety-related; ketchup that simply tastes flat or has darkened is unappetizing but generally not dangerous. Crystallization of sugar around the bottle neck is normal and safe; wipe clean before continuing to use. When in doubt about whether ketchup is still good, discard.