Germapalooza: How to Keep Kitchen Sponges Clean

What Are Some Good Ways to Kill the Bacteria?

Since it was discovered that kitchen sponges tend to host large colonies of bacteria, a handful of home remedies for killing the germs have been introduced in recent years. Let's take a look at some of the more popular home remedies:

  1. Wash the sponge in the dishwasher: The most obvious way of cleaning the sponge is to toss it in the dishwasher with the dirty dishes, but there has been little proof that the method actually works. During a TV appearance, Sharon Franke, the kitchen technology and appliances director at Good Housekeeping Research Institute, explained that putting sponges in the dishwasher isn't the best course of action because the water in the dishwasher probably doesn't get hot enough to kill all the bacteria.
  2. Put the sponge in the microwave: A 2007 University of Florida study found that nuking kitchen sponges for about two minutes in the microwave was enough to effectively sterilize the sponge and kill all bacteria in it. Many news outlets reported the findings without mentioning that sponges should be wet before putting them in the microwave, prompting many people to zap dry sponges, which is a serious fire hazard. The University of Florida later issued an advisory that sponges should be completely wet and have no metallic content before they are put in the microwave.
  3. Dip the sponge in bleach: Chlorine bleach is one of the most widely used household disinfectants because it is tried-and-true. Experts recommend regularly soaking sponges in a bleach solution that is heavily diluted with water. When working with bleach, it's a good idea to wear rubber gloves and be careful not to breathe in fumes.
  4. Dip the sponge in lemon juice or vinegar: If you (understandably) feel a bit queasy about using bleach in the same area where food is prepared, you might want to try dipping your sponges in lemon juice or regular old white vinegar. Several studies back it up, proving that vinegar is an effective way of killing bacteria. The U.S. Department of Agriculture (USDA) recommends dipping sponges in lemon juice for about one minute to disinfect them.