Q. I read that there is a way to sterilize sponges in the microwave, but I didn’t get all the instructions. How long do they stay in the microwave?
This technique would be a lot easier for us. Currently my wife pours boiling water on the kitchen sponge every day.
A. Kitchen sponges that sit around are frequently contaminated with nasty germs that can cause illness. Your wife hit upon one way to sterilize the sponge so that wiping a counter doesn’t spread bacteria all over it.
An easier option is to wet the sponge, wring it out and nuke it for two minutes in the microwave. The heat kills the worrisome bacteria along with viruses. When scientists tested an specially prepared infected sponge they found that:
At 100 percent power level, it was found that the heterotrophic plate count (i.e., total bacterial count) of the wastewater was reduced by more that 99 percent within 1 to 2 minutes, and the total coliform and E. coli were totally inactivated after 30 seconds of microwave radiation.
(Journal of Environmental Health, Dec. 2006).
It is important that the sponge be damp. Soon after this recommendation was published, some people tried it without wetting the sponge. Sponges caught on fire, smelled up kitchens and ruined microwave ovens. Please exercise caution and common sense if you plan to microwave your kitchen sponges. As with anything you microwave, please be careful so as not to burn yourself. Those sponges can get got!