If you are a person who cooks a lot (or doesn't have a dishwasher), you definitely end up using your fair share of kitchen sponges. Those cheerful bright yellow and green numbers get through a sink full of dishes without number, but there comes a time in every sponge's life when things begin to go downhill. So how can you tell when a sponge is all sponged out?
This is a matter, somewhat, of preference, and of how often and how seriously you use your kitchen sponge. But, as Philip Tierno Jr, a professor of microbiology at the NYU School of Medicine, told Self on the subject, "The kitchen is a germy place, and the germiest item in it is a sponge." Makes sense really—it's a moist, porous environment, and therefore an ideal environment for all kinds of bacteria.
Tack on the fact that we typically use them to wipe up things like raw chicken juice and dirty plates and you’ve got quite the recipe for Salmonella. You're actually much more likely to contract food poisoning from your own kitchen than from a restaurant, and your sponge might be a culprit. Fun! However, Tierno doesn't recommend tossing out your kitchen sponge after every usage, rather sanitizing it way more often.
Fortunately, sanitizing your sponge isn’t hard, and there are a couple of different ways to do it.
To sanitize a sponge, you can either submerge it in a mixture of nine parts water to one part bleach. Afterward, wring it out and let it air dry on a dish rack. Or you can zap it in the microwave in a bowl of water for about a minute. The fact that it’s in water is key, because as the water boils and evaporates it kills bacteria. And here's the thing: You really should be sanitizing your sponge after each and every use to avoid any unfun gastrointestinal distress. Yes, this may sound like an unnecessary drag (and in reality, you’re probably more likely to do it once a day or even once a week), but it’s worth adding to your chore list and making time for sponge sanitizing as often as possible.
If after washing dishes, you walk away and quickly notice your hands wreak of mildew-y kitchen sponge that’s an indication that bacteria has started to form. But just because it stinks like no tomorrow doesn’t mean you have to throw it away. If you notice a stench, stop using the sponge and thoroughly sanitize it before you use it again.
If you do sanitize your sponge after every use, it will probably last you 30 to 45 days, at which point it will likely become too worn out to really use. But if you aren't you might still be wondering how often should you should change it out? The CDC recommends changing your sponge every two weeks. In fact, some experts recommend you change your sponge out once a week. Yes, really.