How To Clean & Disinfect A Kitchen Sponge

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Your kitchen sponge can be handy for spills and a final wipe down, but the rest of the day, it’s just sitting there, growing bacteria and mildew in a moist environment. Before you pick it up and use it again, it needs to be disinfected.

Soap alone will not work; there are two consistent recommendations for killing the bugs currently partying in your kitchen sponge – bleach and heat.

kitchen sponge bacteria

Stay vigilant! One good round of disinfecting kills the bacteria currently on your sponge. Once you start using it again, bacteria will find your sponge very hospitable again.

How To Disinfect A Sponge With Bleach

If you’re sensitive to the smell of bleach, be aware that you can now purchase bleach with improved scents such as lavender and lemon. For those of us with a skin sensitivity to bleach, rubber gloves will be necessary.

If you’re still worried about using such a harsh chemical, you can still get the impact of bleach using a milder solution, which many may find less irritating to skin and eyes.

To save yourself time and make your task more convenient, pre-mix water and bleach together and store it somewhere safe between uses. Every time you want to sterilize your sponge, decant it into a smaller bowl to soak your sponge.

Ensure the stored liquid is sealed with a lid and labeled, and keep it out of reach of small children.

  1. Ensure your sponge is as clean as possible before disinfecting by rinsing it under warm water and adding a little dish soap.
  2. Rinse it thoroughly.
  3. Mix one part bleach to nine parts water – about 14 ounces of bleach to 14 cups of water – in a dedicated cleaning container that you can safely store away.
  4. Decant enough solution into a smaller bowl – use enough to completely immerse your sponge.
  5. Soak your sponge in the liquid and leave it for anywhere from 30 seconds to five minutes.
  6. Remove the sponge and rinse it in water.
  7. Wring the sponge thoroughly and allow it to air dry.
  8. It’s now ready to use.

Soaking your sponge in bleach mixed with water can kill the bacteria on your sponge and keep your kitchen from becoming a biohazard.

Speaking of biohazards, it’s important to remember that no matter what your new bleach smells like, you should never mix it with any ammonia-based product. This mixture results in chloramine vapor, a toxic gas.

If you’re cooking with children and cleaning up together, you may want to move any ammonia-based products out of the kitchen to avoid cross-contamination.​

How To Microwave A Sponge

  1. Clean your sponge using dish soap and wring it out.
  2. Rinse well with water.
  3. Fill a small bowl with water (add lemon juice or vinegar – as below – if you wish) and soak the sponge in the solution.
  4. Remove the sponge from the water and place it on a microwave proof dish in the microwave – your sponge should be well saturated.
  5. Heat on high for two minutes. Never microwave a dry sponge. If you see smoke, stop the process immediately.
  6. Wait a few minutes for the sponge to cool before attempting to touch it, or remove it using tongs.
  7. Squeeze out any remaining water and let it air dry.

You can freshen the air in your kitchen and clean your dishwashing sponge any time you need to by mixing a few drops of lemon juice and water in a small bowl.

Dunk your sponge in this liquid and rinse it, then microwave your sponge. This will cook the bacteria and release a fresh lemon scent in your kitchen. You can also do this any time your sponge starts to smell a little musty.

Vinegar can work as a sponge soak prior to the microwave technique. With products like vinegar and lemon juice, you’ll kill off mold as well as bacteria.

When planning for how to clean a sponge in the microwave, be aware that it’s the heat that’s most important. Vinegar, ammonia and lemon juice have antibiotic qualities, but you’ll have the best effect with a form of acid and heat. Finally, no matter what, never microwave a dry sponge.​

Never microwave a sponge that has a metal component – particularly items like scouring pads. The metal may cause sparks and potentially damage your microwave.

Cleaning Sponge FAQs

Why Do I Need To Disinfect My Sponge?

Sponges are extremely handy for picking up small spills and wiping away crumbs. They are used for any and all kitchen tasks – sometimes even for cleaning up organic messes like meat or blood from cooking.

However, because of their construction, they hold on to moisture and stay damp – thus bacteria friendly – for much longer than a plain dishwashing cloth would.

Deep within the moist cells of your sponge, nasty bacteria have plenty of food and water in which to grow.

Your sponge can easily grow dangerous bacteria like campylobacter, salmonella, staphylococcus, listeria or E.coli; all of these can cause food poisoning and potentially make you very ill.

Soap is not strong enough to kill bacteria, so you need to disinfect your sponge using either high temperatures or bleach.

How Long To Microwave A Sponge?

You need to microwave the sponge long enough for the water to boil – this will help ensure the temperatures are intense enough to kill most bacteria.

We recommend microwaving your wet sponge for two minutes.

Be careful that your sponge is thoroughly soaked; if it’s too dry, there is the chance the sponge may catch on fire.

How Often Should You Change Your Sponge?

Even disinfect your kitchen sponge daily, with regular use it will become thin and less effective.

Your kitchen sponge is one of the most important aspects of keeping your kitchen environment bacteria free, so it should be the cleanest tool.

Both for health and convenience, we recommend you replace your sponge every two to three weeks.

Final Thoughts

Household sponges can be run through a dishwasher to good effect, though this cleaning method is not as effective as bleach or a high dosage of heat.

Also, be aware that sponges can get tossed around in the spray inside your dishwasher to the detriment of your drain mechanism.

Other options include washing sponges in the washing machine or soaking them in ammonia or vinegar. When determining how to sanitize a sponge, it’s important to get into a habit and do it at least once a day.​

Many of us have a hard time using bleach because of skin irritation and may forget to microwave our sponge.

If you have a few sponges on hand, you can run them through the washing machine with other items that need bleach. This option bleaches your sponge, protects your family from dangerous bacteria and lessens the amount of bleach you have to handle.

Written By Tara Williams

Tara is a food writer that has been editing and authoring articles for KitchenSanity since its founding. Her writing offers personal experience from experimentation with food and recipe creation. If you’re looking for simple tips, she will make your journey in the kitchen straightforward with a dash of fun.