That sponge sitting near your kitchen sink can be harboring huge amounts of germs. Bacteria, yeast, and mold can all live in a kitchen sponge — meaning that the cleaning you do can actually spread germs around! Health experts suggest cleaning your sponge at least once every week (though twice a week is better).
The best way to clean your sponge? Use the microwave. Simply wet the sponge and microwave it for a full minute. A study from the United States Department of Agriculture’s Henry A. Wallace Beltsville Agricultural Research Center in Maryland found that the microwave was the best at killing bacteria, yeast, and mold in kitchen sponges. Nearly everything in the sponge was killed using this method.
The second best choice is to run your sponge through a full wash and dry cycle in your dishwasher. It kills almost as much bacteria, yeast, and mold as the microwave method does. Just running your sponge under really hot water isn’t enough; the water gets MUCH hotter during a dishwasher cycle.
Soaking your sponge in bleach is a decent way to kill bacteria, but it has little to no effect on yeast or mold. Other soaks (like lemon juice) in the experiment didn’t have much effect at all.
The wear and tear of running your sponge through the dishwasher might make your kitchen sponge give up the ghost a little sooner than usual, but isn’t it worth it to have a clean, sanitized sponge? The thought of smearing yeast, mold, and bacteria over my dishes and calling them “clean” is really kind of icky to me. I live alone, so I don’t run my dishwasher much more than once a week (it takes a while for the dishwasher to fill up) but I’m going to try alternating. Run the sponge through the dishwasher when I run it (usually on Friday) and run a wet sponge through the microwave mid-week.