You’ve likely scrubbed down your bathroom at least once in the past few weeks. (Or at least, we hope you have.) You’ve probably also wiped down your phone a time or two. But when was the last time you gave your kitchen the same treatment? Because you use antibacterial soap for you and your dishes in there frequently, you might think it’s relatively clean. However, it turns out your kitchen might be the largest breeding ground for germs in your entire house.
Germs love to hang out in dark, wet, and warm places — and chances are your kitchen is at least two of those things most of the time. In fact, one initial study from NSF International, an independent public health organization, found that the kitchen is the germiest place in your home. Their studies typically don’t include more than 25 homes, but the organization has volunteers take more than 30 samples within each one, adding more than 600 swabs and samples to test for the presence of E. coli, salmonella, staph, mold and yeast, and other germs that can cause allergies or foodborne illnesses.
Germs in your kitchen
Since that first study in 2011, NSF has continued to gather samples from popular items in the home and see how contaminated they are. Over the years, they’ve compiled a list of places you’re most likely to find germs — and the places you should be cleaning more often.
Though some are incredibly obvious, such as cutting boards, counter tops, and handles on doors and refrigerators, others aren’t quite as noticeable. In other cases, you likely know you should be cleaning something, but probably aren’t taking the time to do it properly. Since studies are beginning to show that foodborne illnesses can happen at home just as much as restaurants, it’s important to set up a more thorough cleaning regimen.
“We’re not trying to scare people,” Lisa Yakas, microbiologist and manager of the Home Products Certification Program for NSF International, told ABC News. Instead, she suggests taking the extra effort to clean these areas first, and then establish routine cleaning habits moving forward.
1. Dish sponges and rags
Why it’s gross: Yes, you probably already know your sponge is a breeding ground for germs. But just how much can be a little shocking. In NSF’s initial 2011 study, 75% of sponges and rags sampled contained at least one form of coliform bacteria, which includes salmonella and E. coli and is a potential indicator of fecal contamination. A majority of samples also contained yeast or mold, and a small percentage even contained bacteria that can cause staph infections. This was by far the most germ-ridden item in the house, containing more than 321 million microorganisms per gram.
How to clean it: Keep in mind that not all of those microorganisms were harmful, and not all bacteria will cause you to get sick. However, sponges are inherently damp, and thus more likely to also breed the nastier bacteria as well. Real Simple suggests rinsing your sponge after each use with hot water, and then allowing it to dry in a ventilated soap dish. At the end of each day, pop the wet sponge in the microwave for 1 minute, which should zap most of the bacteria that has stuck around. Cloths should be hung on the towel rack between uses, and then tossed in the laundry and washed with hot water after 1 day of use.
2. Coffee reservoir
Why it’s gross: When was the last time you actually cleaned the reservoir in your coffee maker, where the water sits before brewing a new pot? If you’re anything like the homeowners in the NSF tests, probably not lately. According to the study findings, those reservoirs contained more bacteria than your toilet seat does, most notably mold and yeast microorganisms.
How to clean it: NSF suggests following the manufacturer’s directions for cleaning out the entire coffee maker — not just the pot — every 40 to 80 brew cycles, or at least monthly. Though directions will likely vary, this often includes adding up to four cups of undiluted vinegar to the reservoir, and allowing it to sit for 30 minutes. Then run the vinegar through the unit, followed by two to three cycles of fresh water, or until the vinegar odor is gone.
3. Stove knobs
Why they’re gross: You probably run an antibacterial wipe or sponge over your stovetop frequently, but do you take the time to clean the knobs of your stove and oven as well? You’re constantly touching them, often as you’re preparing food, which means there’s ample time for bacteria to build up. Those knobs made the Top 10 list of germiest places in the entire house, ranking above the remote control, refrigerator handle, and toilet seat.
How to clean them: Once you figure out how to remove and reinstall the knobs on your stove, this is a pretty simple one to resolve. All you have to do is remove them once a week to wash them in hot soapy water, and then allow them to dry properly before reinstalling them.
4. Vegetable drawer
Why they’re gross: Chances are, you clean out your refrigerator every few months or so. When it comes to your vegetable drawers, however, it should be happening much more often. In a followup study in 2013, NSF found that the veggie drawers in your refrigerator are one of the most germ-ridden places in your kitchen, sometimes contaminated with salmonella and listeria, along with yeast and mold spores. Storing fresh produce in there without properly cleaning the drawers is a recipe for foodborne illnesses.
How to clean them: Yakas of the NSF told ABC that those drawers should be washed with warm soapy water, thoroughly dried, and deodorized with baking soda if necessary. She didn’t provide a timeline for how often you should do so, but most other containers and such are recommended for once per week, or at least once every few weeks.
5. Blender gasket
Why it’s gross: If you have the type of blender where the blade unscrews from the base and the main container, make sure you’re cleaning the rubber gasket. That’s the piece that fits between the bottom and the blade to make sure liquid doesn’t leak out of the container when you’re using it. If you’re not fully disassembling kitchen appliances that come into contact with food, you’re likely allowing bacteria to build up. NSF data showed that gasket can contain E. coli, salmonella, and yeast and mold.
How to clean it: Completely unscrew your blender after use, and consult your manual for cleaning instructions. You might be able to put that rubber ring in your dishwasher, Good Housekeeping reports, but can otherwise clean it after every use with hot soapy water, allowing all the pieces to dry completely before reassembling.
6. Refrigerator water dispenser
Why it’s gross: In its second study, NSF found that the water dispenser on your refrigerator is one of the most germ-laden areas in your kitchen. It’s likely based on the amount of human contact, coupled with the wet environment. The water and ice dispensers weren’t a large cause of concern for disease-causing bacteria, but were a large source for yeast and mold, which can worsen allergies of people who are sensitive to spores.
How to clean it: You’ll want to check the manufacturer’s directions first, but both the Huffington Post and Do It Yourself suggest cycling vinegar through the system, much like the process for cleaning your coffee pot. The vinegar won’t pose any health risk as opposed to other cleaning products, and all you’ll have to do after the water is hooked back up is cycle enough through so you don’t taste the vinegar anymore. Vinegar can also be used to clean the outside spout and surrounding area.
7. Kitchen sink
Why it’s gross: You might occasionally run your sponge around the sink to wash away any lingering remnants from food prep or your dinner, but it is still often one of the germiest places in your kitchen. It had the fifth-highest number of microorganisms in the houses that took part in the 2011 NSF study, and had a presence of coliform bacteria and yeast or mold.
How to clean it: WebMD suggests using a solution of bleach and water to clean the sink once a day, and allowing the mixture to filter down the drain. NSF says to scrub the sides and bottom of the sink once or twice per week with a disinfecting cleaner, and pour 1 tablespoon of bleach mixed with one quart of water down the drains and disposals. Additionally, the organization suggests putting your kitchen sink strainers through the dishwasher once per week.
8. Can opener
Why it’s gross: You might wipe off the can opener with a dishcloth every now and then, but invisible food particles can continue to stick there, providing a hotbed of activity for bacteria. NSF found yeast and mold bacteria, along with traces of E. coli and salmonella in some samples.
How to clean it: Whether you have a manual opener or an electric one, it’s time to pull out some vinegar and a toothbrush. That’s what Home Ec 101 suggests, anyway, and makes sense based on the other cleaning tips in the kitchen already. If it’s been years since your can opener was cleaned, and the gunk is gross, The Huffington Post suggests soaking the entire thing in a bowl of vinegar, for a few hours or up to overnight. Use a toothbrush to scrub away lingering particles, rinse thoroughly, and dry completely.
9. Salt and pepper shakers
Why they’re gross: The salt and pepper shakers on your dining room table might have more germs than you thought. According to WebMD, they can be a common place to find cold virus germs — which means they’re also likely to contain other microorganisms, too.
How to clean them: When you wipe down the table or finish washing the dishes, it doesn’t hurt to run that same cloth over your salt and pepper shakers, too. Obviously, WebMD points out that washing your hands before and after dinner is also a good way to make sure unwanted germs aren’t making it to your dinner table.
10. Knife block
Why it’s gross: Worse than the can opener in NSF’s studies were the knife blocks. Your knife blocks probably don’t get a buildup of food on them, most likely, but that trace bacteria can then grow in the dark recesses of where you keep your knives. In most cases, the researchers were more likely to find mold and yeast traces than the other bacteria that can cause foodborne illnesses.
How to clean it: The NSF recommends removing any knives from the block, then washing the entire thing in hot soapy water. To clean the slots, the organization suggests using a small brush, like the ones used to clean baby bottles. Then, dilute 1 tablespoon of bleach in 1 gallon of lukewarm water — a solution that will further sanitize the block. Submerge the entire block, or simply fill each slot with the liquid and allow it to sit for 1 minute. Rinse thoroughly and turn upside down on a clean surface to dry. If used frequently, you should follow this process monthly, making sure to completely dry all knives before placing them back in the block.
11. Rubber spatula
Why it’s gross: Many rubber spatulas used for baking and mixing still have two parts — the paddle and the handle it slips off of. If you don’t separate the two each time you clean it, you’re likely allowing bacteria to build up around that edge, leaving the possibility it spreads to the foods you’re preparing. NSF’s tests revealed traces of E. coli and yeast or mold on some of the spatulas it sampled.
How to clean it: Though some spatulas are easier to separate than others, all you have to do is take it apart after use, either washing it by hand in hot soapy water or putting it through the dishwasher. As long as you allow both parts to dry completely before putting it back together, you shouldn’t have a problem. Alternatively, if you’re due for a new spatula anyway, consider buying the silicone version that’s all one piece. No nooks and crannies equals less bacteria.
12. Food storage containers
Why it’s gross: When was the last time you gave a second thought to how clean your Tupperware is? If you store leftovers in containers with the rubber sealed lids, food particles and other bacteria might unknowingly get caught in the seal. Homeowners in the 2013 NSF study didn’t even consider these containers to be bacteria-laden, but in reality they contained traces of salmonella, along with yeast and mold.
How to clean them: There are numerous sources and tips for cleaning your plastic food storage containers. That suggests you’re not alone if you typically just wash them quickly and forget about them. If the containers smell from leftovers or are stained, Good Housekeeping suggests letting them soak in a solution of baking soda and water for 30 minutes — or even using a bit of chlorine bleach before washing in hot, soapy water. Food52 offers other options, including storing them with a pinch of salt or crumpled newspaper. To avoid the yeast and mold, be sure the containers dry completely before storing them in your dark cabinets.
13. Meat compartment
Why it’s gross: Are you picking up a theme with your refrigerator? If you’re cleaning out your vegetable drawers, you might as well pay some attention to the drawer where you keep your deli meats and cheeses, too. Those are pre-cooked and won’t contaminate your storage in the way raw meats could. But the NSF study still found a number of issues, including E. coli and salmonella. Not a great recipe for avoiding food poisoning, if you ignore it for too long.
How to clean it: As with the vegetable drawer, washing the compartment with warm, soapy water should do the trick. Rinse thoroughly, and dry completely before putting it back in the refrigerator. Both the USDA and The Kitchn suggest cleaning the entire fridge semi-regularly, so make time for that every now and then. Typically, the strongest type of cleaner you’ll need is a solution of vinegar and water, so you won’t potentially add chemicals to your food from harsher products.
14. Refrigerator door seal
Why it’s gross: When you clean the inside of your refrigerator, make sure to wipe down the seal and the outside, too. Some of the NSF tests revealed listeria on the insulating seal, likely from contamination from produce at some point. The refrigerator door handle also tested positive for coliform bacteria, which includes E. coli and salmonella, along with staph, yeast, and mold spores.
How to clean it: While you’re wiping down the interior of your refrigerator, use warm soapy water — or that vinegar solution — to clean the entire outer surfaces, too. If you typically wipe down your kitchen with other cleaning solutions, it might not be a bad idea to do the same on the refrigerator. As always, drying the seal and the handle thoroughly with a towel is best to prevent yeast or mold from growing again.
15. Counter top
Why it’s gross: The counter top is ground zero for food preparation, and it probably isn’t surprising that you need to clean it more often than you think. (And no, wiping it with a paper towel to dry it off doesn’t count here.) You likely prepare fresh produce, raw meat, and a host of other foods on the counter tops — not to mention contaminate it with germs from everyday life. The good news: Counter tops are flat surfaces, which means it’s harder to germs to grow. They’re also typically well-lit, another strike against bacteria. However, the original NSF study found the presence of coliform bacteria on the surfaces, along with yeast and mold.
How to clean it: Better Homes & Gardens suggests cleaning with a germ-killing cleaner of your choice regularly, and drying with a microfiber cloth to dry thoroughly and prevent streaking. The site also provides guidance on the best tips for each type of counter top surface. How Stuff Works provides similar guidance, adding that seamless materials, such as common plastic laminate, make it the easiest to get rid of germs completely. At the very least, wipe down the work surfaces once a day with your cleaner of choice — hot soapy water at a minimum.