Our Test Kitchen pros share their tips on keeping your sponges clean and safe.

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No matter what type of sponge you use, I don't have to tell you: they can get gross. A still buzzed-about 2017 Scientific Reports study revealed that an average of 362 different species of bacteria live on a single sponge, with 82 billion pathogens found in just 1 cubic inch! While most were generally harmless, other research has shown the presence of E. coli and Salmonella, which can cause illness. Here are the best practices we use in the Test Kitchen:

An illustration of germs on a sponge
Credit: W. Scott Matthews - Getty Images / EricFerguson

Test Kitchen Tips for Keeping Your Sponges Free of Germs

Keep Your Sponges Clean & Sanitize Them 

I wash my sponge frequently with hot water and dish soap. I also make sure to wring out excess water and keep it in a spot where it dries out well (try your dish rack and open a nearby window if possible to speed the process). This helps keep it grunge-free. 

But what about ridding it of invisible bacteria? I reached out to microbiologist Charles Gerba, Ph.D., of the University of Arizona, who's an expert on pathogen transmission. He says that in studies he's led, soaking the sponge in bleach or using a disinfectant cleaner works well to reduce bacterial load. It's also worth checking the package instructions: one widely available brand, for example, says to sanitize their sponges in the dishwasher or by boiling, but not to microwave them. 

Just Use It for Dishes

Even if you regularly disinfect your sponge, avoid potential cross-contamination by using it only for dishes. Using your sponge on dishes and counters increases your chances of spreading germs—especially after handling raw meat and fish, eggs and dairy. For countertop messes, grab a paper towel, disposable wipe or washable cloth instead.

Replace Often. 

Even with daily cleanings, experts agree it's best to dispose of your sponge at least once a week. (If you've really put yours through the wringer, like if you've been cooking more than usual, consider replacing it every few days.) To reduce waste, I cut new sponges in half—so I end up tossing only two per month.

This article originally appeared in EatingWell magazine April, 2021