Expired Milk
That carton of milk sitting in your fridge might be silently brewing bacteria, even if it looks perfectly fine. The three most dangerous dairy products to keep in your refrigerator past their expiration dates are soft cheeses, milk, and yogurt, according to a culinary instructor, because of their nutrient-dense environments where bacteria and other harmful microorganisms thrive. Unopened milk lasts about a week in the fridge after its expiration date, but if the milk smells sour, or if the carton looks bloated, it’s time to throw it away. Milk, assuming proper refrigeration, should last five to seven days past its sell-by date before turning sour. The danger zone isn’t just about taste – spoiled milk can harbor dangerous bacteria that could make you seriously ill. Keeping milk at the right temperature of 39 degrees F is crucial because anything between 40 and 140 degrees F is particularly dangerous, as this temperature danger zone range is where bacteria thrive the best and multiply the fastest. Don’t trust your eyes alone; trust your nose and that instinct telling you something’s off.
Moldy Soft Cheeses
That innocent-looking spot of mold on your cottage cheese or brie isn’t something you can just scrape off and forget about. If mold is present, scrapping it off won’t make the product safe to eat, and dairy products, especially soft cheeses such as cottage cheese, with mold should be discarded because the mold may have spread mold threads throughout it even if you are unable to see it. Unlike hard cheeses where you might be able to cut away moldy sections, soft cheeses have a different texture that allows mold to penetrate deeper. The creamy, moisture-rich environment of soft cheeses creates the perfect breeding ground for harmful bacteria. Other warning signs include discoloration (browning, darkening, or white, blue, green, or black spots), unpleasant, bitter, sour, or generally off tastes, and rancid, sour, or ammonia-like smells. What looks like a small problem on the surface could be hiding a much bigger contamination issue throughout the entire product. Remember, when it comes to moldy soft cheese, there’s no salvaging it – the whole thing needs to go straight into the trash.
Spoiled Ground Meat
Ground meat has a shorter shelf life than you might think, and keeping it too long can be downright dangerous. Ground beef and pork are good for one to two days in the fridge from the date of purchase, or you can keep them in the freezer for three to four months. Ground beef, turkey, veal, pork, lamb can be kept for up to 2 days. The grinding process exposes more surface area to bacteria, making ground meat much more susceptible to contamination than whole cuts. When ground meat goes bad, it doesn’t just taste unpleasant – it can harbor dangerous pathogens like E. coli and Salmonella. The number of recalls because of Listeria, Salmonella or E. coli increased significantly in 2024 and comprised 39% of all recalls, with 1,392 people becoming ill from food that was recalled. Look for changes in color, texture, or smell, and if you’re questioning whether it’s still good, don’t take the risk. It’s better to be safe than sorry and not risk getting sick, especially if you’re especially at risk for food poisoning, because “When in doubt, throw it out!”
Rancid Mayonnaise
Mayonnaise might seem harmless sitting in your fridge door, but it’s actually one of the riskier condiments once it goes bad. Creamy salad dressings, when not replaced frequently, are breeding grounds for foodborne illnesses as well, and many contain varieties of egg or cheese-based ingredients, which can quickly go bad and increase chances of bacteria growth if not disposed of after the labeled expiration date. Like mayonnaise, salad dressings have a life of up to two months after the seal has been broken. The egg-based nature of mayonnaise makes it particularly vulnerable to bacterial growth when stored improperly or kept past its prime. You’ll know it’s time to toss it when the mayo starts to separate, develops an off smell, or changes color. Condiments used past their expiration dates can downgrade your food by tasting flat or off—or even making you sick. Since mayonnaise is often used in dishes that won’t be cooked afterward, like sandwiches or potato salad, there’s no “kill step” to eliminate any bacteria that might have developed. Always store them in the fridge, as condiments stored in the refrigerator last months longer than they would otherwise, and the cool environment helps ward off bad bacteria.
Cloudy Pickle Brine
Those pickles you’ve been ignoring in the back of your fridge might be sending you warning signals you shouldn’t ignore. Fermented foods are known for their long shelf lives (they’ll last several months if they’re completely surged in brine), but that doesn’t make them invincible, so throw pickles out if the brine has a cloudy appearance or a weird smell is coming from the jar. Consume them within three months of opening for the tastiest results, while quick pickles are best eaten within two weeks. When pickle brine turns cloudy, it’s often a sign that harmful bacteria have taken over the jar, disrupting the delicate balance that keeps pickles safe. The cloudiness indicates that the acidity level might have changed, which is crucial for preventing dangerous bacterial growth. Even though pickles are preserved foods, they’re not immune to spoilage, especially once the jar has been opened and exposed to air. Trust your nose in times of doubt and give the condiment in question a quick whiff. If the brine smells off or the pickles have developed a slimy texture, it’s time to say goodbye to the entire jar.
Expired Yogurt
Yogurt might seem like it should last forever since it’s already fermented, but expired yogurt can actually be quite dangerous. The three most dangerous dairy products to keep in your refrigerator past their expiration dates are soft cheeses, milk, and yogurt, because of their nutrient-dense environments where bacteria and other harmful microorganisms thrive. The live cultures in yogurt that are beneficial when fresh can become problematic when the yogurt is past its prime. When it comes to food safety, it is best to discard expired foods to prevent foodborne illness. Spoiled yogurt often develops a watery consistency, with liquid separating from the solids, and may smell sour or off. Yogurt can be frozen (though their textures may be impacted). Keep yogurt in the refrigerator at 39 degrees F because keeping anything between 40 and 140 degrees F is particularly dangerous, as this temperature danger zone range is where bacteria thrive the best and multiply the fastest. Unlike some other dairy products where you might have a few days of leeway, yogurt’s complex bacterial environment means that once it goes bad, it can harbor harmful microorganisms that could cause food poisoning.
Wilted Leafy Greens
Those sad-looking salad greens lurking in your crisper drawer aren’t just unappetizing – they could actually be dangerous. Lettuce and other raw fruits and vegetables represent one of food safety experts’ main concerns, as such foods were responsible for nearly half of foodborne illness outbreaks in 2019. These foods can be risky because there isn’t a “kill step,” which means the produce comes to consumers without being cooked or heated in a way that kills off microbes. When leafy greens start to wilt, develop slimy patches, or show brown spots, they’re creating the perfect environment for harmful bacteria like E. coli and Salmonella to flourish. In February, the agency decided against publicizing an E. coli outbreak in lettuce that hospitalized dozens of people in late 2024. The high surface area and moisture content of leafy greens make them particularly vulnerable to bacterial contamination. Unlike other vegetables that you might cook before eating, salad greens are typically consumed raw, meaning any bacteria present will go directly into your system. Rather than using the expiration date to determine whether to throw out food, your senses should be your guide, as the taste, smell and look of the product will tell you if it’s spoiled and should be thrown out.
Forgotten Leftovers
That container of pasta from last week might seem like a money-saving lunch option, but old leftovers are actually one of the most dangerous things hiding in your fridge. Eat leftovers within 48 hours or freeze them if you think this won’t be possible. Cooked egg dishes, soups and stews, cooked casseroles, gravy, broth, patties, and nuggets, store-cooked dinners and entrees can be kept for up to 4 days. The problem with leftovers is that they’ve already been through multiple temperature changes, and each time they’re reheated and cooled, they create more opportunities for bacterial growth. Food that has been left out of the fridge for over 2 hours should not be consumed, even if it was put back in the fridge. A good rule of thumb is to throw out a perishable item after 2 hours at room temperature or half that time in high heat. Even if leftovers look and smell fine, they can still harbor dangerous bacteria that multiply invisibly. When in doubt, throw it out. The convenience of having ready-made meals isn’t worth the risk of food poisoning, especially when you consider how quickly bacteria can multiply in cooked foods that aren’t stored properly.
Dented or Rusty Canned Goods
That dented can of tomatoes might seem like a bargain find, but damaged canned goods can be extremely dangerous. Follow proper handling of canned foods and discard cans that are dented, rusted or swollen. Canned products with sharp dents near the seam, bulges or signs of leakage are indicators that the product should not be used. When cans are damaged, the seal that keeps harmful bacteria out can be compromised, potentially allowing deadly organisms like Clostridium botulinum to grow inside. Canned foods are sterile, so they won’t host bacteria, but eventually, the taste and texture of the items inside will deteriorate over time. However, this sterility only applies to undamaged cans. Avoid buying bulging, rusted, leaking, or deeply dented cans as they have a higher chance of being spoiled. Botulism is particularly dangerous because the toxin it produces can be fatal, and unlike other forms of food poisoning, it’s not something you can recover from easily. High-acid canned foods (e.g., tomatoes and fruits) will keep their best quality for 12 to 18 months, whereas low-acid canned foods (e.g., meats and vegetables) will keep for two to five years. But these timeframes only apply to properly sealed, undamaged cans.
Old Cooking Oils
That bottle of cooking oil you’ve been using for months might be more dangerous than you realize. Take note of oily salad dressings that taste more bitter than usual, as this is caused by oxidation and is probably a sign it’s time to replenish your stock. When oils go rancid, they don’t just taste bad – they can actually be harmful to your health. Rancid oils contain free radicals and other compounds that can contribute to inflammation and other health problems. You’ll know your oil has gone bad when it develops a bitter, sour, or metallic taste, or when it starts to smell musty or paint-like. Don’t store canned goods above the stove, under the sink, in a damp garage or basement, or in any place exposed to high or low temperature extremes. The same principle applies to oils – heat, light, and air exposure can cause them to break down much faster. Wiping down the rim after each use or squeeze will prolong its shelf life. Unlike some other foods where you might have visual cues like mold or obvious spoilage, rancid oil can be tricky to detect until it’s already causing problems in your cooking. When in doubt, it’s better to invest in fresh oil rather than risk ruining your meals or potentially harming your health.
