We're all aware of many areas in our kitchen that can become havens for germs: the telltale aromatic sponge, the trash can that's probably overdue for a good disinfecting, and the grimy inside of the microwave that's probably covered in spatter and in need of a deep clean. But unfortunately even the most fastidious among us probably aren't attending to a number of other, more mysterious places in our kitchens that are also prone to bacteria.
"Most people know the usual kitchen bacteria hotspots, but some of the worst offenders are the ones you don't even think about," says Dennis Littley, chef and recipe expert at Ask Chef Dennis. Moisture traps, warm zones, high-touch areas, and specific kitchen devices where splatter is out of your line of sight are all culprits for hidden bacteria. Littley and other kitchen and cleaning experts chime in on nine surprising places in your kitchen where bacteria may be lurking.
1. Knife block
The inside and outside of your knife block should be periodically cleaned, according to cleaning experts.
If you have a countertop block where your knives are stored, this was commonly mentioned among experts as a place known for harboring hidden germs. "If you slide damp knives back into the slots or don't wash them thoroughly before storing, moisture and food residue get trapped inside, creating the perfect place for bacteria and mold to grow," Littley says.
You can help prevent bacterial buildup by always making sure your knives are fully clean and dry before putting them away, but an actual cleaning of the knife block is in order at least once in a while.
"A few times a year, turn the block upside down, shake out any loose debris, and disinfect the slots with warm water and vinegar," Littley says. "A pipe cleaner or straw brush is perfect for scrubbing inside."
2. Spice jars
The more you use a spice, the likelier it is to have germs on the jar.
All of those little bottles sitting in your cupboards or spice rack probably need cleaning, too. Can you think of even one time when you ever wiped them down?
"Despite regular cleaning of sinks and countertops, spice jars are often overlooked and can harbor germs that lead to foodborne illnesses," says Vanessa Bossart, founder of GreenTerra Cleaning.
It's not the herbs or spices inside the jars that are creating the issue, however, but rather how we typically handle them. "Bacterial buildup occurs when spice jars come into contact with contaminated hands, especially after handling raw meat," Bossart says.
Before you put the spice jars away, she advises cleaning them with a fresh, soapy cloth after each use or a disinfectant wipe.
"To make sure the jar is thoroughly disinfected, pat it dry with a fresh towel or paper towel if it is damp," she adds.
3. Can opener blades
Run your can opener through the dishwasher, under hot soapy water or clean the blades with an old toothbrush.
Another kitchen tool that comes into regular contact with food is your can opener. Just because it's a tiny blade tip coming into contact with your stewed tomatoes doesn't mean it won't get contaminated if you're not cleaning it after using it.
"Food particles get stuck and rot," says Shanina Knighton, PhD, Research Associate Professor in Nursing at Case Western Reserve University.
To prevent this from happening, "simply rinse your can opener after each use with hot, soapy water, Knighton says. The mechanism can be susceptible to rust, so try to dry it as much as you can before putting it away, and consider replacing it every so often.
4. Refrigerator door gasket
The seal around your fridge door is one high--traffic area that should be cleaned regularly.
While the refrigerator door handle is a high-touch area that could certainly use some attention now and then, there's a part of the door that you've probably never considered. "Most people are aware that their refrigerator is one of the places in the kitchen that attract bacteria," says Delah Gomasi, CEO of Maid For You. "What's surprising, though, is that there is something inside the refrigerator that's crawling with bacteria yet somehow never cleaned," he says.
The refrigerator door gasket -- the rubber seal that runs along the edge of the door -- is almost never attended to, even for those who are cleaning out the fridge. "Basically, it's the perfect environment for bacteria to thrive in," Gomasi says. "Most refrigerators have a heating element to prevent condensation, which is why you'll find the gasket warm to the touch. And since the rubber seal has folds, humidity and moisture get trapped inside them."
Combined with food particles and spills, it can be a breeding ground for bacteria, or even the dreaded black mold. Gomasi recommends a solution of diluted household bleach -- one part bleach to three parts water -- and a cotton swab or brunch to get out the gunk from between the folds. "It's important to do a thorough job here," he says, "so a follow-up wipe down with a clean, damp microfiber cloth is highly recommended, as well as drying the rubber after cleaning it."
5. Freezer
You may know to disinfect your fridge, but don't forget about your freezer, too.
Another part of your refrigerator may also be giving you trouble, where you didn't even realize trouble could live. "The perfect place for bacteria to flourish is wherever it's wet and dark," says Forrest Webber, owner of Bear Brothers Cleaning. "A perfect example is your freezer," he says.
"Even though it's freezing cold, bacteria can still accumulate, and most people rarely, if ever, clean their freezers. It's easy to visualize how that could cause bacterial buildup."
Since you really should also be defrosting your freezer once a year for efficiency's sake, it's a good opportunity to give it a proper disinfect during that time by using soapy water or disinfectant wipes, and a clean towel to dry.
6. Sink overflow hole
Most sinks have an overflow drain in the back and it can be a hotbed for bacteria.
The sink itself is obviously a place where germs can linger, but the basin at least gets a wipe down once in a while. (Right?) But there's more that may need dealing with when it comes to disinfecting your space.
"Your sink usually has a small opening near the top of the basin called the overflow hole, and it's a hidden bacteria hotspot," says Danny Pen, President of New Era Plumbing & HVAC.
"It traps moisture, food particles and grease over time, creating the perfect breeding ground for bacteria and mold," he says. "Since water rarely flushes through the overflow hole with enough force, debris sticks inside and decomposes. Add warm temperatures and humidity, and you've got a hidden petri dish."
A petri dish in the area you typically use to make things clean is not a comforting thought. The fix here is a quick one, at least, which is merely to pay attention to the overflow hole whenever you are scrubbing down your sink. (And maybe do that more often, while we're at it.)
Read more: 15 Places You're Probably Forgetting to Clean
7. Scrubber holders
Your sponge holder needs to be cleaned just as often as your sink.
While we're at the sink, even if you are regularly switching out your sponges, you might not entirely be solving the problem if you're putting them back on a dirty holder. "Sponges sit wet, creating a bacteria party," Knighton says.
Do you want to go to that party? I do not. Cleaning this holder should be quite easy to make a habit of. Knighton advises washing it in the dishwasher or with hot, soapy water once a week.
8. Air fryer coils
Clean the coils above your air fryer cooking basket for a safer kitchen and better tasting food. Â
As a proud air fryer acolyte, this one may haunt my dreams. "One surprising bacteria trap is the heating element in your air fryer or toaster oven," Littley says. Consider the splatter in your microwave, which at least has the decency to make itself visible to you. Now consider the enclosed space of the air fryer.
According to Littley: "Most people clean the basket or tray but completely forget about the heating element itself. Grease and tiny food particles splatter onto the coils, and over time, they burn and create a layer of buildup, which can make your food taste off and provide the perfect environment for bacteria."
Littley advises to make sure to unplug the appliance first, then tackle it by using a damp, soapy cloth or a small brush to gently scrub off any debris. "Doing this every few weeks keeps it clean and prevents bacteria from building up."
Read more: Clean Out Your Air Fryer in 3 Simple Steps
9. Coffee maker reservoir
A coffee reservoir that holds water for brewing needs regular cleaning.
One of the dirtiest places in your kitchen may actually be one that you rely upon to help you get started every day. Let that horrifying fact sink in. A study by the health organization NSF revealed that the reservoir of your coffee maker is one of the top areas for bacteria buildup in the kitchen.
"It's a dark, damp spot where mold thrives," says Knighton. (Mushroom coffee might be trending, but this is not what we had in mind.) But the solution is simple, which is simply to run a monthly cycle with diluted vinegar and wipe out the reservoir with a cloth.