I like to keep my kitchen sparkling and often reach for a sponge and some sort of surface cleaner. And although I don't get grossed out easily, the kitchen sponge is something that freaks me out if I think about it too long. All those gross germs hanging around, spreading themselves from surface to surface *shudder* I really can't handle it. However, I know that a sponge is a great kitchen tool - it's a reusable, quick way to wipe down dishes, clean countertops, etc. So what's a gal to do? Do I rinse it under warm soapy water or do I clean it with bleach? What's the best way to keep a sponge in rotation, while keeping the spread of bacteria to a minimum? Well, lucky for us, scientists at the Agricultural Research Service tested several methods for reducing risks in reused sponges. They did this by soaking sponges at room temperature for 48 hours in a ground beef/lab growth mixture, then they went about "cleaning" them. To learn what they discovered,

The ARS scientists treated the sponges in five commonly used ways.

  1. Soaked for 3 minutes in a 10% chlorine bleach solution.
  2. Soaked in lemon juice or deionized water for 1 minute.
  3. Heated in a microwave for 1 minute.
  4. Placed in a dishwasher operating with a drying cycle.
  5. Left untreated.

Strangely, the sponges soaked in the bleach solution, the lemon/deionized water and the sponges left untreated each only killed 37-87% of the bacteria. While microwaving killed 99.9999% and the dishwasher killed 99.9998%. Microwaving and dishwashing also killed most (over 99%) of the mold and yeasts, while the other treatments left them behind.

Long story short, if you really want to clean out those sponges, you might want to take them for a spin in the dishwasher or microwave between uses.

Source: Agricultural Research Service