How to Sanitize a Kitchen Sponge
From now on, we’ll always wring out sponges and store them in a place where they can dry between uses. But even a clean kitchen sponge can still get grimy. Worse, it can stay damp on the inside even when it looks and feels dry on the outside.
To learn how to clean them, we turned to NSF International, a public health and safety organization that develops standards and certifications. Lisa Yakas, a microbiologist and home product certification expert at NSF International, proposed three methods:
METHOD 1: Dampen your sponge and microwave it for at least 2 minutes.
METHOD 2: Run your sponge through your dishwasher on a setting that reaches at least 155 degrees and has a heated dry cycle (sometimes called sani-rinse, sani-wash, or sanitation cycle), preferably every time you run your dishwasher.
METHOD 3: Submerge your sponge in a bleach solution (¾ cup of bleach for every gallon of water) for at least 5 minutes and then rinse it thoroughly.
After using any of these methods, allow the sponge to dry completely before using it again, ideally in a dish rack or a container that allows air to circulate around all surfaces of the sponge.