Have you ever opened a jar of half-used tomato sauce only to find furry white spots of mold floating on top? While some spoiled food is quite obvious—all you need do is open the container and take a whiff—others are less so. Especially pantry staples that you tend to keep on hand all of the time, and maybe too long.  These awesome kitchen tricks are how to tell if these 7 foods that you probably always have on hand are fresh.

Top Photo by Rebecca Orlov | Epic Playdate on Unsplash

Updated for 2022


How to tell if eggs are fresh | Cool Mom EatsPhoto by Kelly Neil on Unsplash

Finding out if eggs are fresh is actually fun (it’s sink or swim, baby!) and is something that you should even do with expired eggs. Sometimes, they’re still good and this test will avoid food waste and save money. Bon Appetit describes my favorite kitchen trick: the float test for fresh eggs.

Food Hacks gives even more detail on how to test eggs for freshness, including a method for looking at eggs that you accidentally crack. You’ll also find ideas in this article for what to do with a bunch of eggs that are about to go bad and some clever uses for discarded eggshells, too. Think sidewalk chalk: Pretty cool, huh?


How to tell if cheese if fresh | Cool Mom EatsPhoto by Rebecca Orlov | Epic Playdate on Unsplash

My kids are generally down with stinky cheese, but if they see even one bit of unexpected mold, they think that I’m trying to poison them. Really? I feed them, clothe them, play with them, wipe their tears, and then I’m going to kill them? But, ewww, Mom, that cheese is moldy! I admit that a little white mold can be off-putting, but I won’t throw away a one-pound brick of $13 cheddar because of some surface mold. And, according to the USDA, I don’t have to. (For the record, in the case of hard cheeses, they recommend cutting off at least one inch around and below the mold spot before consuming.)

While hard cheeses may be easier to monitor, creamy, stinky cheeses can pose more of a challenge. They do have a particular odor, after all. Food52 goes in-depth and shows you how to tell when your cheese is no longer fresh. Because, sometimes, the funk is just too funky.


How to tell if butter is fresh | Cool Mom EatsPhoto by Sincerely Media on Unsplash 

Butter can definitely go bad, though only if left out or kept in the fridge for a really long time. Like 6 months longer than the date on the package (and even, then, it’s worth checking to make sure because it might still be good). Thing go bad much faster when butter is left out. The folks at Can It Go Bad detail how to tell if butter has gone rancid but, if there’s any question, give a little taste to see if it’s sour or gamey. A small amount of bad butter won’t do you harm.


How to tell if oil is fresh | Cool Mom EatsPhoto by Fulvio Ciccolo on Unsplash 

One time, late at night, no less, I poured a cup of canola oil into my otherwise finished cake batter only to find that it was rancid. Ever since, I always check my oil, especially that random bottle of fancy walnut oil that I tucked in the back of my cupboard after buying it two years ago. (You know the one?) Nutritionist Toby Amidor shares tips on how to tell if oil has gone rancid and also gives advice on how to prevent oil from spoiling with proper storage.

Our friends at the Kitchn explain that olive oil has three enemies and how to avoid them with proper storage. These tips are especially important if you buy in bulk and tend to keep one of those huge containers of oil on hand.


How to tell if vinegar is bad | Cool Mom EatsPhoto by Bulbul Ahmed on Unsplash 

But what about vinegar? Have you ever seen a slimy clump forming in your bottle? The Kitchn also tells us why vinegar has an almost indefinite shelf life, and what exactly that jelly-like substance is, which funny enough, is called a “mother.”


How to tell if flour is fresh | Cool Mom EatsPhoto by Vlad Kutepov on Unsplash 

It’s important to pay close attention to whole wheat and other whole grain flours. Because these flours are less refined, they retain the germ, which contains healthy oils that can spoil. I’m convinced that many people don’t like whole wheat flour because they’ve used rancid flour without realizing it.

Flour really shouldn’t have much of a smell, and if it does, it’s most likely gone bad. Recipe Tips has a great guide for storing flours to make sure that it stays fresh as long as possible. You definitely want to consider an airtight storage container (affiliate) rather than just setting bags on the pantry shelf. But once you see mold or pests, spot discoloration, or get a musty, oily, or generally unpleasant smell, toss it.

Baking Powder

How to tell if baking powder is fresh | Cool Mom EatsPhoto by Addilyn Ragsdill @clockworklemon.com on Unsplash 

Another staple you should always check for freshness is baking powder. Because there is nothing worse than doing the work of making a cake or cupcakes and finding that they don’t rise because of inactive baking powder. Pastry genius David Leibowitz has a great trick for how you can easily test if your baking powder is still good. I use it whenever in doubt, even just a little bit.

Related: What to do with that expired baking soda. Don’t throw it out!

Mark Sisson at Mark’s Daily Apple has an awesomely comprehensive guide on how long foods really last, and also shares his most important rule: When in doubt, throw it out! My kids will be happy to know that I, too, subscribe to that philosophy and have no intention of poisoning by cheese.