No judgement here, but how often do you replace your kitchen sponge? Do you use the same one for dishes and wiping down countertops, or do you have separate sponges for each job?
Kitchen sponges handle a lot of dirty work. Like swimming pools, we understand that they are a favorite hotspot among active bacteria – friendly and not so friendly. To be on the safe side, we think it’s a good idea to sanitize them on a regular basis. How is that typically done? By running them through the dishwasher or heating them up in the microwave.
In our minds, we’re killing the evil bacteria that gets picked up from tables, raw meats, sinks, and countertops. That is, for the people who don’t use paper towels or disposable wipes to clean up the kitchen.
But now, new information suggests that dirty sponges stay dirty, even after being “sanitized.” A study by researchers at a German university found that not only is bacteria surviving on sponges, but it’s possible that cleaning them may actually increase bacterial growth.
Led by microbiologist Dr. Markus Egert, the study examined 14 sponges used in everyday households to compare to ones used and tested in their lab. Sponge donors stated that they regularly cleaned them. However, concentrations of bacteria were found deep in the pores of the sponges as well as the surface area.
But it wasn’t just your average Salmonella strain mixed in with some E. coli. Scientists found over 350 types of bacteria, with the most prevalent being Moraxella osloensis. According to the study, Moraxella has been found on stoves, sinks, faucets, and refrigerator doors. Additionally, one of the sources of Moraxella is human skin.
Even after being disinfected in the microwave or with hot, soapy water, the sponges still harbored large traces of this bacteria and others in smaller amounts. When you’re reusing instead of replacing these sponges, you’re essentially redepositing the bacteria. Cross-contamination is also a problem in a high-traffic area like the kitchen.
Think about that for a moment. The study emphasized that kitchen surfaces and humans are reliable when it comes to germ transmission. With Moraxella, it’s known to cause that funky smell in dirty laundry (from us), as well as the funky smell in used sponges.
Though Moraxella in general isn’t as dangerous as say, E. coli, it’s still been found to cause problems for people with weakened immune systems. Considering all the places that bacteria can be found in a kitchen, it’s recommended to make sure you wash your hands regularly (especially before and during food prep), and cut out any habits that would make an unwelcome microscopic guest feel welcome.
More importantly, if your sponge doesn’t pass the sniff test, it’s time to throw it out. If you can’t remember the last time you switched it out, it’s time to throw it out. These researchers suggest replacing used sponges once a week, while others recommend once a month.
Sorry, but a microwave or hot steaming bath just ain’t cutting it. Bacteria is a fact of life in our kitchens, bathrooms, and bodies, but who wants to purposely hang out with the unsavory versions for weeks at a time? Change your sponge!
Are you guilty of being a sponge neglector sometimes? How do you clean kitchen surfaces? Will this study influence your sponging habits?