When to Replace Your Kitchen Sponges

Sponges are every kitchen's dirty little secret. (Emphasis on the word "dirty.") A new sponge quickly becomes a cozy hangout for lots and lots of bacteria. In an eye-opening 2017 study, German researchers found up to 54 billion bacteria per cubic centimeter on the 14 used sponges they tested. Fortunately, many of the bacteria were harmless to humans but the study did find some varieties of salmonella and E. coli, which could lead to food-borne illnesses. So, what can you do to have clean dishes and a clean bill of health? Here are some options.

Give your sponges a thorough cleaning.

According to the United States Department of Agriculture (USDA), the best way to kill bacteria in reusable sponges is to clean them in your microwave or dishwasher. These appliances eradicate almost 100 percent of bacteria. If you use a microwave, first wet the sponge thoroughly and leave it in for one minute; don't put a dry sponge in the microwave because it could catch on fire. As an alternative, you could clean sponges in the top rack of the dishwasher with the drying cycle on.

Throw them out before they smell.

Wring sponges out after each use and clean them every other day. While those are great habits to get into, even a sponge sanitized this often could accumulate bacteria over time, so replace yours every two weeks—or even sooner if they develop an odor or fall apart. Rather than use the same sponge to wash dishes and wipe off counters, it's better to assign different sponges to different tasks to prevent contamination.

Choose a different cleaning tool.

Traditional sponges aren't the only way to clean. Martha likes Sqwishful ($6 for three, sqwishful.com), a 100-percent renewable plant-based option. It's biodegradable and compressed to reduce its carbon footprint when you eventually dispose of it. Donna Smallin Kuper, author of Cleaning Plain & Simple ($16.95, barnesandnoble.com) and a certified home cleaning technician, stopped using sponges after seeing that German study: "I don't consider myself a germaphobe, but the idea of spreading germs all over my kitchen counter when I thought I was cleaning it made me switch to dish cloths. They're more sanitary, economical, and environmentally friendly than traditional sponges." She uses a clean cotton dish cloth, which is smaller than a dish towel, every day.