How To Clean a Kitchen Sponge

Clean and disinfect your kitchen sponge with these methods that target harmful germs.

Like a smelly kitchen rag, dirty sponges are ideal breeding grounds for yeast, mold, and bacteria. One study found that a dirty kitchen sponge contained 362 different types of bacteria. The methods below eliminate harmful germs by causing them to burst due to heat from boiling, or by damaging the proteins inside them so they die.

Microwaving a Wet Sponge

First, squeeze and rinse your sponge several times under warm water then get it soaking wet again. Next, put the wet sponge into the microwave and run it on high for 1 minute for polymer foam sponges, or 2 minutes for cellulose, sea, or microfiber sponges. This will cause the water in the sponge to boil, killing the bacteria. Be sure to let the sponge sit until it’s cool enough to handle. Finally, squeeze any remaining water out and let it air-dry.

Use the Dishwasher

First, rinse and squeeze your sponge several times to remove food particles, then put it on the top rack of your machine for a full wash and dry cycle. Once the cycle ends, squeeze excess moisture out of the sponge and let it air dry. With this method, the combined hot wash temperature and heated drying cycle eliminate germs. (There are 53 more things you can clean in the dishwasher if you want to make it a full load.)

Boiling Sponges in Vinegar Water

To deodorize, clean and disinfect your sponge with vinegar, combine 3 cups water and 1 cup white vinegar in a large saucepan. Bring this to a boil, add your kitchen sponge, and let it boil for 2 minutes. Turn off the heat and allow the solution to cool, then wring out your sponge and let it dry.

Bleach and Water

First, rinse your sponge several times to remove food particles, then wring it out well. Next, combine 1 quart of cool water with 2 tablespoons of chlorine bleach in a bowl and let your sponge soak in this mixture for 10 minutes. Finally, squeeze out the excess moisture and let your sponge air dry. Bleach kills germs by damaging their proteins and it will also help remove food stains on your sponge.

How Often Should You disinfect Sponges?

Rinse your sponge after each use and make sure it fully air dries. Disinfect it at least every other day, although daily is ideal. Methods like microwaving or adding them to the dishwasher make this a fairly simple task. If you have neither appliance, consider rotating an assortment of sponges. Keep dirty ones sealed in a plastic bag in the freezer then boil several at a time.

Frequently Asked questions

Below are questions that readers often ask about cleaning and disinfecting sponges. If you have a question not answered below, please leave it in the comments. I update this section frequently to include new questions.

Does spraying with hydrogen peroxide or vinegar work to clean my sponge?

These methods, although popular on the internet, are not strong enough to eliminate dangerous bacteria according to tests by the Agricultural Research Service’s Food Technology and Safety Laboratory (ARS).

How often should I replace my sponge?

Replace cellulose, natural, and polymer foam sponges every two weeks. Microfiber sponges can last several months if properly cleaned.