Assume the germiest place in your home is the bathroom? Think again, because the highest concentration of germs is probably in your kitchen (when’s the last time you deep cleaned your Keurig?) And the germiest of all household items are … dish sponges and rags, according to NSF International. The independent public health organization tasked 22 families with swabbing 30 household items to see which things harbored the most germs, and dish sponges and towels came out on top as the filthiest of the filthy.
Of course, the last thing you want to do is wash your dishes or swab down your kitchen countertops with a germ-saturated sponge. Luckily, cleaning a sponge is breeze.
But before we get into how to clean a sponge, some more good news; the majority of germs on your kitchen sponges are environmental bacteria, and they are for the most part harmless, says microbiologist Jason Tetro, author of The Germ Code and The Germ Files and host of the Super Awesome Science Show podcast. That being said, there is the chance for sponges to carry some potential pathogens that could get you seriously sick. Some have familiar names such as Salmonella and E. coli; others might not be as well known, like the blood-infecting Moraxella and the respiratory pathogen Acinetobacter, Tetro says.
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So how do you make sure that your kitchen sponge doesn't turn into a petri dish for germs and become a vector for bacteria that could potentially make you sick? Studies suggest there are two ways to keep your sponge clean,. The first is to throw it in the dishwasher on the top rack and let it go through the full wash and dry cycle. The second is to microwave it (make sure it's wet first) for two minutes on high. Be sure to let it cool down before you remove it from the microwave so you don’t burn your hand. Each of these couldn't be simpler, but "both are going to be more effective than detergent, boiling water, and even 10% bleach disinfection," Tetro says.
Another smart tip: Always wring your sponge out after every use to help keep it dry, says Kathy Turley, a cleaning expert with Home Clean Heroes. Bacteria thrives in moist places, and this simple act can keep it at bay.
To avoid cross-contamination and potential foodborne illnesses, Turley also recommends using separate sponges for cleaning your dishes and wiping down your kitchen countertops. Never wait until your kitchen sponges are smelly to wash them. This is a quick chore you should stay on top of every few days, she says.
If you don't toss them in the dishwasher or microwave regularly, sponges should be changed about once a week, Tetro recommends.
As for your dish towels and cloths, they also are commonly loaded with bacteria, like E. coli and coliform, including strains that can make you sick. Tetro says dish towels can be tossed in the laundry and washed in hot water, which will keep them safe.
How often you wash them should depend on how often you're cooking at home and using them.
"If they are used constantly for food preparation, cleanup, and washing, changing them every few days would be best," he says. "If they are just there to dry hands and maybe clean dishes, then they can last about a week."
Brittany Anas is a former newspaper reporter (The Denver Post, Boulder Daily Camera) turned freelance writer. Before she struck out on her own, she covered just about every beat—from higher education to crime. Now she writes about food, cocktails, travel, and lifestyle topics for Men’s Journal, House Beautiful, Forbes, Simplemost, Shondaland, Livability, Hearst newspapers, TripSavvy and more. In her free time, she coaches basketball, crashes pools, and loves hanging out with her rude-but-adorable Boston Terrier that never got the memo the breed is nicknamed "America’s gentleman."
