Answer Save. When it comes to how long does the kefir stay fresh after opening, it depends. Keep it away from direct sunlight, the stove or other sources of heat. Just watch for "bubbles" in it, … A vinaigrette is a good example, as both olive oil and vinegar last a long time, and additional ingredients such as maple syrup or mustard also keep really well. If you don't use ketchup often, refrigerate. Jan 15, 2009 #2 . If you open it soon after buying, it pretty much should last until the date on the label.If, on the other hand, you open it near the date on the label, you shouldn’t expect it to stay tasty for more than 5 days. How long do they last? Most commercial mayonnaises, like Hellman's Real Mayonnaise or Sir Kensignton's Mayonnaise, are shelf-stable before opening.That's why the bottle or jar can sit unrefrigerated in the supermarket. Find Ratings Refrigerators. Banana ketchup can be left out indefinitely because it contains sodium benzoate, a preservative that used to be in tomato ketchup until Heinz decided on a naturally preserved recipe. An acidic environment makes it inhospitable for most foodborne microorganisms to proliferate. How Long to Keep Ketchup and Other Common Condiments. So, that’s up to you whether you want it refrigerated or not. How long does opened,unrefrigerated ketchup last? Store butter out of the fridge only if the room temperature stays below 70–77°F (21–25°C). Consumer Reports News: April 20, 2012 04:08 PM. Ketchup lasts for up to a month in the pantry. How long does ketchup stay good unrefrigerated? ShaiserManelli, Jan 14, 2009. Yes, it has a long shelf life because ketchup is naturally acidic. NaeKid YourAdministrator, eh? If, on the other hand, it’s a dairy-based dressing like ranch, it definitely won’t last as long, and 3 to 4 days of good quality is all you can hope for in most cases. To maximize its shelf life, you should put it in the refrigerator after you open it. Ketchup can be left out for 1 month. The ketchup of China in the 17th century was not like what we have today! Okay so I have this ketchup that expired around 4 months ago.It's opened and unrefrigerated.I don't want it to go to waste,so buying more ketchup is not an option I want to chose.Thanks! This is why restaurants can, and often do, leave them out on the table. ShaiserManelli, Jan 14, 2009. ... Ketchup will last a long time unrefridged, it's very acidic. Unopened ketchup stays fresh for 12 months unrefrigerated. Ketchup has a long history that spans centuries and many countries. Pay attention to your ketchup’s color, thickness, and flavor for an indication of its general quality. 2 … Some people don’t mind cold ketchup upon serving, and some prefer to have ketchup unrefrigerated. You open up your cupboard, or take a peek in your camping cooking supplies, and you find a bunch of old ketchup packets. Let’s find out. Adam Berry/Getty Ketchup is a tomato-based condiment that's a popular topping for hot dogs, burgers, and fries. But once you open it up, you've got to store mayo in the fridge, and Sir Kensington's notes that refrigerated mayonnaise will "be safe to enjoy approximately 2 months after you first open your jar …